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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 53 - 53
23 Jun 2023
Schemitsch EH Nowak LL De Beer J Brink O Poolman R Mehta S Stengel D Bhandari M
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We aimed to use data from a randomized controlled trial (RCT) comparing the sliding hip screw vs. intramedullary nailing (IMN) for trochanteric fractures to examine complication rates between those managed with a short vs. long IMN.

This is a secondary analysis using one arm of an RCT of patients ≥18 years with trochanteric fractures. We examined differences in fracture-related (femoral shaft fracture, implant failure, surgical site infection (SSI), nonunion, limb shortening, and pain) and medical (organ failure, respiratory distress, stroke, deep vein thrombosis [DVT] gastrointestinal upset, pneumonia, myocardial infarction, sepsis, or urinary tract infection) adverse events (AE), and readmission between short vs. long IMNs.

We included 412 trochanteric fracture patients, 339 (82.2%) of whom received a short (170mm–200mm) nail, while 73 (17.7%) received a long (260mm–460 mm) nail. Patients in the long group were more likely to be admitted from home (vs. an institution), and have comorbidities, or more complex fracture types.

Patients in the long group had higher rates of fracture-related AE (12.3%) vs. the short group (3.5%). Specifically, SSI (5.5% vs. 0.3%) and pain (2.7% vs. 0.0%) were significantly higher in the long group. Patients in the long group were also more likely to develop DVT (2.7% vs. 0.3%), and be readmitted to the hospital (28.8% vs. 20.7%).

Following covariable adjustment, long nails remained associated with a higher odds of fracture-related AE (5.11, 1.96–13.33) compared to short nails. We found no association between the adjusted odds of readmission and nail length (1.00, 0.52–1.94).

Our analyses revealed that trochanteric fracture patients managed with long IMN nails may have a higher odds of fracture-related AE compared to short nails. Future research is required to validate these findings with larger event rates, and further optimize IMN for trochanteric fracture patients.


Bone & Joint Open
Vol. 4, Issue 3 | Pages 168 - 181
14 Mar 2023
Dijkstra H Oosterhoff JHF van de Kuit A IJpma FFA Schwab JH Poolman RW Sprague S Bzovsky S Bhandari M Swiontkowski M Schemitsch EH Doornberg JN Hendrickx LAM

Aims

To develop prediction models using machine-learning (ML) algorithms for 90-day and one-year mortality prediction in femoral neck fracture (FNF) patients aged 50 years or older based on the Hip fracture Evaluation with Alternatives of Total Hip arthroplasty versus Hemiarthroplasty (HEALTH) and Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trials.

Methods

This study included 2,388 patients from the HEALTH and FAITH trials, with 90-day and one-year mortality proportions of 3.0% (71/2,388) and 6.4% (153/2,388), respectively. The mean age was 75.9 years (SD 10.8) and 65.9% of patients (1,574/2,388) were female. The algorithms included patient and injury characteristics. Six algorithms were developed, internally validated and evaluated across discrimination (c-statistic; discriminative ability between those with risk of mortality and those without), calibration (observed outcome compared to the predicted probability), and the Brier score (composite of discrimination and calibration).


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 55 - 55
1 Dec 2022
Nowak L Campbell D Schemitsch EH
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To describe the longitudinal trends in patients with obesity and Metabolic Syndrome (MetS) undergoing TKA and the associated impact on complications and lengths of hospital stay.

We identified patients who underwent primary TKA between 2006 – 2017 within the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We recorded patient demographics, length of stay (LOS), and 30-day major and minor complications. We labelled those with an obese Body Mass Index (BMI ≥ 30), hypertension, and diabetes as having MetS. We evaluated mean BMI, LOS, and 30-day complication rates in all patients, obese patients, and those with MetS from 2006-2017. We used multivariable regression to evaluate the trends in BMI, complications, and LOS over time in all patients and those with MetS, and the effect of BMI and MetS on complication rates and LOS, stratified by year.

270,846 patients underwent primary TKA at hospitals participating in the NSQIP database. 63.71% of patients were obese (n = 172,333), 15.21% were morbidly obese (n = 41,130), and 12.37% met criteria for MetS (n = 33,470). Mean BMI in TKA patients increased at a rate of 0.03 per year (0.02-0.05; p < 0 .0001). Despite this, the rate of adverse events in obese patients decreased: major complications by an odds ratio (OR) of 0.94 (0.93-0.96; p < 0 .0001) and minor complications by 0.94 (0.93-0.95; p < 0 .001). LOS also decreased over time at an average rate of −0.058 days per year (-0.059 to −0.057; p < 0 .0001). The proportion of patients with MetS did not increase, however similar improvements in major complications (OR 0.94 [0.91-0.97] p < 0 .0001), minor complications (OR 0.97 [0.94-1.00]; p < 0 .0330), and LOS (mean −0.055 [-0.056 to −0.054] p < 0 .0001) were found. In morbidly obese patients (BMI ≥ 40), there was a decreased proportion per year (OR 0.989 [0.98-0.994] p < 0 .0001). Factors specifically associated with major complications in obese patients included COPD (OR 1.75 [1.55-2.00] p < 0.0001) and diabetes (OR 1.10 [1.02-1.1] p = 0.017). Hypertension (OR 1.12 [1.03-1.21] p = 0.0079) was associated with minor complications. Similarly, in patients with MetS, major complications were associated with COPD (OR 1.72 [1.35-2.18] p < 0.0001). Neuraxial anesthesia was associated with a lower risk for major complications in the obese cohort (OR 0.87 [0.81-0.92] p < 0.0001). BMI ≥ 40 was associated with a greater risk for minor complications (OR 1.37 [1.26-1.50] p < 0.0001), major complications (1.11 [1.02-1.21] p = 0.015), and increased LOS (+0.08 days [0.07-0.09] p < 0.0001).

Mean BMI in patients undergoing primary TKA increased from 2006 - 2017. MetS comorbidities such as diabetes and hypertension elevated the risk for complications in obese patients. COPD contributed to higher rates of major complications. The obesity-specific risk reduction with spinal anesthesia suggests an improved post-anesthetic clinical course in obese patients with pre-existing pulmonary pathology. Encouragingly, the overall rates of complications and LOS in patients with obesity and MetS exhibited a longitudinal decline. This finding may be related to the decreased proportion of patients with BMI ≥ 40 treated over the same period, possibly the result of quality improvement initiatives aimed at delaying high-risk surgery in morbidly obese patients until healthy weight loss is achieved. These findings may also reflect increased awareness and improved management of these patients and their elevated risk profiles.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 80 - 80
1 Dec 2022
Nauth A Dehghan N Schemitsch C Schemitsch EH Jenkinson R Vicente M McKee MD
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There has been a substantial increase in the surgical treatment of unstable chest wall injuries recently. While a variety of fixation methods exist, most surgeons have used plate and screw fixation. Rib-specific locking plate systems are available, however evidence supporting their use over less-expensive, conventional plate systems (such as pelvic reconstruction plates) is lacking. We sought to address this by comparing outcomes between locking plates and non-locking plates in a cohort of patients from a prior randomized trial who received surgical stabilization of their unstable chest wall injury.

We used data from the surgical group of a previous multi-centred, prospective, randomized controlled trial comparing surgical fixation of acute, unstable chest wall injuries to non-operative management. In this substudy, our primary outcome was hardware-related complications and re-operation. Secondary outcomes included ventilator free days (VFDs) in the first 28 days following injury, length of ICU and hospital stay, and general health outcomes (SF-36 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores). Categorical variables are reported as frequency counts and percentages and the two groups were compared using Fisher's Exact test. Continuous data are reported as median and interquartile range and the two groups were compared using the Wilcoxon rank-sum test.

From the original cohort of 207 patients, 108 had been treated surgically and had data available on the type of plate construct used. Fifty-nine patients (55%) had received fixation with non-locking plates (primarily 3.5 or 2.7 mm pelvic reconstruction plates) and 49 (45%) had received fixation with locking plates (primarily rib-specific locking plates). The two groups were similar in regard to baseline and injury characteristics. In the non-locking group, 15% of patients (9/59) had evidence of hardware loosening versus 4% (2/49 patients) in the locking group (p = 0.1). The rate of re-operation for hardware complications was 3% in the non-locking group versus 0% in the locking group (p = 0.5). No patients in either group required revision fixation for loss of reduction or nonunion. There were no differences between the groups with regard to VFDs (26.3 [19.6 – 28] vs. 27.3 [18.3 – 28], p = 0.83), length of ICU stay (6.5 [2.0 – 13.1] vs 4.1 [0 – 11], p = 0.12), length of hospital stay (17 [10 – 32] vs. 17 [10 – 24], p = 0.94) or SF-36 PCS (40.9 [33.6 – 51.0] vs 43.4 [34.1 – 49.6], p = 0.93) or MCS scores (47.8 [36.9 – 57.9] vs 46.9 [40.5 – 57.4], p = 0.95).

We found no statistically significant differences in outcomes between patients who received surgical stabilization of their unstable chest wall injury when comparing non-locking plates versus locking plates. However, the rate of hardware loosening was nearly 4 times higher in the non-locking plate group and trended towards statistical significance, although re-operation related to this was less frequent. This finding is not surprising, given the inherent challenges of rib fixation including thin bones, comminution, potential osteopenia and a post-operative environment of constant motion. We believe that the increased cost of locking plate fixation in this setting is likely justifiable given these findings.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 7 - 7
1 Dec 2022
Nowak L Moktar J Henry P Schemitsch EH
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This study aimed to determine if multiple failed closed reductions (CRs) prior to fixation of distal radius fracture is associated with the odds of complication-related reoperation up to two years post fracture.

We identified all distal radius fracture patients aged 18 or older between the years of 2003-2016 in Ontario, Canada from linked administrative databases. We used procedural and fee codes to identify patients who underwent primary outpatient surgical fixation between 8 and 14 days post fracture, and grouped patients by the number of CRs they underwent prior to definitive fixation. We excluded patients who underwent fixation within 7 days of their fracture to exclude more complex fracture types and/or patients who required more immediate surgery. We grouped patients according to the number of CRs they underwent prior to definitive fixation. We used intervention and diagnostic codes to identify reoperations within two years of fixation. We used multi-level multivariable logistic regression to compare the association between the number of CRs and reoperation while accounting for clustering at the surgeon level and adjusting for other relevant covariables. We performed an age-stratified analysis to determine if the association between the number of CRs and reoperation differed by patient age.

We identified 5,464 patients with distal radius fractures managed with outpatient fixation between 8 and 14 days of their fracture. A total of 1,422 patients (26.0%) underwent primary surgical fixation (mean time to fixation 10.6±2.0 days), while 3,573 (65.4%) underwent secondary fixation following one failed CR (mean time to fixation 10.1±2.2 days, time to CR 0.3±1.2 days), and 469 (8.6%) underwent fixation following two failed CRs (mean time to fixation 10.8±2.2 days, time to first CR 0.0±0.1 days, time to second CR 4.7±3.0 days). The CR groups had higher proportions of female patients compared to the primary group, and patients who underwent two failed CRs were more likely to be fixed with a plate (vs. wires or pins). The unadjusted proportion of reoperations was significantly higher in the group who underwent two failed CRs (7.5%) compared to those who underwent primary fixation (4.4%), and fixation following one failed CR (4.9%). Following covariable adjustment, patients who underwent two failed CRs had a significantly higher odds of reoperation (odds ratio [OR] 1.72 [1.12-2.65]) compared to those who underwent primary fixation. This association appeared to worsen for patients over the age of 60 (OR 3.93 [1.76-8.77]). We found no significant difference between the odds of reoperation between patients who underwent primary fixation vs. secondary fixation following one failed CR.

We found that patients with distal radius fractures who undergo multiple CRs prior to definitive fixation have a significantly higher odds of reoperation compared to those who undergo primary fixation, or fixation following a single CR. This suggests that surgeons should offer fixation if indicated following a single failed CR rather than attempt multiple closed reductions. Prospective studies are required to confirm these findings.


Bone & Joint Open
Vol. 2, Issue 8 | Pages 646 - 654
16 Aug 2021
Martin JR Saunders PE Phillips M Mitchell SM Mckee MD Schemitsch EH Dehghan N

Aims

The aims of this network meta-analysis (NMA) were to examine nonunion rates and functional outcomes following various operative and nonoperative treatments for displaced mid-shaft clavicle fractures.

Methods

Initial search strategy incorporated MEDLINE, PubMed, Embase, and the Cochrane Library for relevant randomized controlled trials (RCTs). Four treatment arms were created: nonoperative (NO); intramedullary nailing (IMN); reconstruction plating (RP); and compression/pre-contoured plating (CP). A Bayesian NMA was conducted to compare all treatment options for outcomes of nonunion, malunion, and function using the Disabilities of the Arm Shoulder and Hand (DASH) and Constant-Murley Shoulder Outcome scores.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 68 - 68
1 Aug 2020
Atwan Y Sprague S Bzovsky S Jeray K Petrisor B Bhandari M Schemitsch EH
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Negative pressure wound therapy (NPWT) is commonly used to manage severe open fracture wounds. The recently completed X randomized controlled trial (RCT) evaluated the effect of NPWT versus standard wound management on 12-month disability and rate of deep infection among patients with severe open fractures of the lower limb and reported no differences. Using data from the Y trial of open fracture patients, we aimed to evaluate the impact of NPWT on the odds of having deep infections and health-related quality of life (HRQL).

Our analyses included participants from the Y trial who had Gustilo II and III lower extremity fractures. To adjust for the influence of injury characteristics on type of dressing received, a propensity score was developed from the dataset. A one-to-one matching algorithm was then used to pair patients with a similar propensity for NPWT.

Mixed effects logistic regression was used to evaluate the association between type of wound dressing and development of a deep infection requiring operative management (dependent variable) in the matched cohort. Gustilo type, irrigation solution, fracture location, mechanism of injury, and degree of contamination were included as adjustment variables. To determine any differences in HRQL between the NPWT and standard wound dressing groups, we conducted two multi-level models with three levels (centre, patient, and time) and included Short Form-12 (SF-12) Physical Health Component (PCS) and SF-12 Mental Health Component (MCS) as dependent variables. Gustilo type, irrigation solution, fracture location, mechanism of injury, degree of contamination, and pre-injury SF-12 scores were included as adjustment variables. All tests were 2-tailed with alpha=0.05.

After applying propensity score-matching to adjust for the influence of injury characteristics on type of dressing used, there were 270 matched pairs of patients available for comparison. The odds of developing a deep infection requiring operative management within 12 months of initial surgery was 4.22 times higher in patients who received NPWT compared to those who did not receive NPWT (Odds Ratio (OR) 4.22, 95% Confidence Interval (CI) 2.26–7.87.

1,329 participants were included in our HRQL analysis and those treated with NPWT had significantly lower SF-12 PCS at all follow-up visits (6w, 3m, 6m, 12m) post fracture (p=0.01). Participants treated with NPWT had significantly lower SF-12 MCS at 6-weeks post-fracture (p=0.03).

Unlike the X trial, our analysis found that patients treated with NPWT had higher odds of developing a deep infection requiring operative management and that being treated with NPWT was associated with lower physical quality of life in the 12 months post-fracture. While there may have been other potential adjustment variables not controlled for in this analysis, our results suggest that the use of this treatment should be re-evaluated.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 31 - 31
1 Aug 2020
Nowak L DiGiovanni R Walker R Sanders DW Lawendy A MacNevin M McKee MD Schemitsch EH
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Delayed management of high energy femoral shaft fractures is associated with increased complication rates. It has been suggested that there is less urgency to stabilize lower energy femoral shaft fractures. The purpose of this study was to evaluate the effect of surgical delay on 30-day complications following fixation of lower energy femoral shaft fractures.

Patients ≥ 18 years who underwent either plate or nail fixation of low energy (falls from standing or up to three steps' height) femoral shaft fractures from 2005 – 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) via procedural codes. Patients with pathologic fractures, fractures of the distal femur or femoral neck were excluded. Patients were categorized into early (< 2 4 hours) or delayed surgery (2–30 days) groups. Bivariate analyses were used to compare demographics and unadjusted rates of complications between groups. A multivariable logistic regression was used to compare the rate of major and minor complications between groups, while adjusting for relevant covariables. Head injury patients and polytrauma patients are not included in the NSQIP database.

Of 2,716 lower energy femoral shaft fracture patients identified, 2,412 (89%) were treated within 1 day of hospital admission, while 304 (11.2%) were treated between 2 and 30 days post hospital admission. Patient age, American Society of Anesthesiologists (ASA) classification score, presence of diabetes, functional status, smoking status, and surgery type (nail vs. plate) were significantly different between groups (p After adjusting for all relevant covariables, delayed surgery significantly increased the odds of 30-day minor complications (p=0.02, OR = 1.48 95%CI 1.01–2.16), and 30-day mortality (p < 0 .001), OR = 1.31 (95%CI 1.03–2.14).

The delay of surgical fixation of femoral shaft fractures appears to significantly increase patients' risk of minor adverse events as well as increase mortality. With only 89% of patients being treated in the 24 hour timeframe that constitutes best practice for treatment of femoral shaft fractures, there remains room for improvement. These results suggest that early treatment of all femoral shaft fractures, even those with a lower energy mechanism of injury, leads to improved outcomes.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 32 - 32
1 Aug 2020
Nowak L Schemitsch EH
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Increased operative time has been previously identified as a risk factor for complications following total joint arthroplasty. The purpose of this study was to evaluate the influence of surgical time on 30-day complications following Total Knee Arthroplasty (TKA) and to determine if there were specific time intervals associated with worse outcomes.

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was utilized to identify patients ≥18 years who underwent TKA between 2005 and 2016 using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complication rates were captured. Multivariable logistic regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for age, sex, American Society of Anaesthesiologists (ASA) class, functional status, smoking status, comorbidities, anesthesia type, and Body Mass Index (BMI). Multivariable linear regression was used to identify independent predictors of duration of surgery.

A total of 213,921 TKA patients (average age 67 ± 10 years) were identified from the database. Within 30-days of the index procedure, 3,321 (1.55%) experienced a major complication, and 6,144 (2.86%) experienced a minor complication. Mean surgical duration was 92 minutes (range 20 – 240). Underweight, or overweight/obese BMI, male sex, hypertension, cancer, dependent functional status, epidural anaesthesia, and ASA class III and IV were determined to be independent predictors of prolonged operation length, while COPD, current smoking, spinal anesthesia, and older age predicted lower operation times.

Operation lengths ≥ 90 minutes significantly increased the risk of both major and minor complications (P>0.01). Specifically, the rates of deep vein thrombosis (DVT), unplanned reintubation, surgical site infection (SSI), sepsis, and wound disruption were higher for patients whose operations lasted ≥ 90 minutes (p 0.05). With respect to specific complications, following covariate adjustment, operation lengths ≥ 90 minutes increased the risk of DVT, deep and superficial incisional SSI, and wound disruption, while operation lengths ≥ 120 minutes increased the risk of deep, non-incisional SSI, and sepsis (P < 0 .01).

Surgical times of ≥90 minutes independently increase the 30-day risk of DVT, infection, and wound disruption following TKA after controlling for other variables that influence operation length. This study confirms the importance of surgical duration on early outcomes following TKA.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 13 - 13
1 Aug 2020
Atrey A Wu J Waddell JP Schemitsch EH Khoshbin A Ward S Bogoch ER
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The purpose of this investigation is to assess the rate of wear the effect once the “bedding in period”/ poly creep had been eliminated. Creep is the visco-elastic deformation that polyethylene exhibits in the first 6–12 weeks. We also assessed the wear pattern of four different bearing couples in total hip arthroplasty (THA): cobalt-chrome (CoCr) versus oxidized zirconium (OxZir) femoral heads with ultra-high molecular weight polyethylene (UHMWPE) versus highly-crosslinked polyethylene (XLPE) acetabular liners.

This was a randomized control study involving 92 patients undergoing THA. They were randomized to one of four bearing couples: (1) CoCr/UHMWPE (n= 23), (2) OxZir/UHMWPE (n=21), (3) CoCr/XLPE (n=24), (4) OxZir/XLPE (n=24). Patients underwent a posterior approach from one of three surgeons involved in the study. All patients received a porous-coated cementless acetabular shell and a cylindrical proximally coated stem with 28 mm femoral heads. Each patient was reviewed clinically and radiographically at six weeks, three and 12 months, two, five and 10 years after surgery. Standardized anteroposterior and lateral radiographs were taken. All polyethylene wear was measured by an independent blinded reviewer. Linear and volumetric wear rates were measured on radiographs using a validated computer software (Polyware Rev. 5). Creep was defined as the wear at 6 or 12 weeks, depending on if there was a more than 10% difference between both measurements. If a greater than 10% difference occurred than the later period's wear would be defined as creep.

72 hips were included in analysis after exclusion of seven revisions, three deaths and 10 losses to follow-up. The annual linear wear rates (in mm/y) at 10 years were (1) 0.249, (2) 0.250, (3) 0.074 and (4) 0.050. After adjusting for creep these rates become were (1) 0.181, (2) 0.142, (3) 0.040 and (4) 0.023. There is statistical differences between raw and adjusted linear wear rates for all bearing couples. The percentage of the radiographically measured wear at 10 years due to creep is (1) 30% (2) 44%, (3) 58.5% and (4) 51.5% with significant differences in couples with XLPE versus those with UHMWPE. There was no significant correlation between age, gender, cup size, tilt, planar anteversion and the linear or volumetric wear rates.

The linear wear rate of both UHMWPE and XLPE are even lower thxdsxzan previously described when creep is factored out. XLPE has again demonstrated far superior linear wear rates at 10 years than UHMWPE. There were no significant differences in wear rate at 10 years between CoCr and OxZir, this may be due to an underpowered study. XLPE exhibits proportionally more creep than UHMWPE within the first 6–12 weeks and accounts for more of the total wear at 10 years as measured radiographically at the end period.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 34 - 34
1 Aug 2020
Nowak L MacNevin M McKee MD Sanders DW Lawendy A Schemitsch EH
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Distal radius fractures are the most common adult fractures, yet there remains some uncertainty surrounding optimal treatment modalities. Recently, the rate of operative treatment of these injuries has been increasing, however, predictors of outcomes in patients treated surgically remain poorly understood. The purpose of this study was to evaluate independent predictors of 30-day readmission and complications following internal fixation of distal radius fractures.

Patients ≥18 years who underwent surgical intervention for distal radius fractures between 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) using procedural codes. Patient demographics, as well as 30-day readmission, complication, and mortality rates were ascertained. Multivariable logistic regression was used to determine independent predictors of 30-day outcomes while adjusting for patient age, sex, American Society of Anaesthesiologists (ASA) class, functional status, smoking status, comorbidities, and Body Mass Index (BMI).

A total of 10,051 patients were identified (average age 58 ±16). All patients received open reduction and internal fixation with no cases of external fixation identified in the data set. Included fractures were 37% extraarticular and 63% intraarticular. Within 30-days of initial fixation 143 (1.42%) patients were readmitted to the hospital, 71 patients experienced a complication, and 18 (0.18%) patients died. After adjusting for relevant covariables, current smoking increased the odds of readmission by 1.73 (95%Confidence interval [95%CI] 1.15 – 2.50), ASA class III/IV vs. I/II increased the odds of readmission by 2.74 (95%CI 1.85 – 4.06), and inpatient surgery vs. outpatient surgery increased the odds of readmission by 2.10 (95%CI 1.46 – 3.03). Current smoking also increased the odds of complications by 2.26 (95%CI 1.32 – 3.87), while ASA class III/IV increased it by 2.78 (95%CI 1.60 – 4.85), inpatient surgery increased it by 2.26 (95%CI 1.37 – 3.74), and dependent functional status increased it by 2.55 (1.16 – 5.64).

In conclusion, patients with severe systemic disease, current smokers and patients undergoing inpatient surgery are at risk for 30-day readmissions and complications following operative treatment of distal radius fractures. In addition, patients with dependent functional statuses are more likely to experience a complication within 30-days.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 32 - 32
1 Jul 2020
Colgan SM Schemitsch EH Adachi J Burke N Hume M Brown J McErlain D
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Fragility fractures associated with osteoporosis (OP) reduce quality of life, increase risk for subsequent fractures, and are a major economic burden. In 2010, Osteoporosis Canada produced clinical practice guidelines on the management of OP patients at risk for fractures (Papaioannou et al. CMAJ 2010). We describe the real-world incidence of primary and subsequent fragility fractures in elderly Canadians in Ontario, Canada in a timespan (2011–2017) following guideline introduction.

This retrospective observational study used de-identified health services administrative data generated from the publicly funded healthcare system in Ontario, Canada from the Institute for Clinical Evaluative Sciences. The study population included individuals ≥66 years of age who were hospitalized with a primary (i.e. index) fragility fracture (identified using ICD-10 codes from hospital admissions, emergency and ambulatory care) occurring between January 1, 2011 and March 31, 2015. All relevant anatomical sites for fragility fractures were examined, including (but not limited to): hip, vertebral, humerus, wrist, radius and ulna, pelvis, and femur. OP treatment in the year prior to fracture and subsequent fracture information were collected until March 31, 2017. Patients with previous fragility fractures over five years prior to the index fracture, and those fractures associated with trauma codes, were excluded.

115,776 patients with an index fracture were included in the analysis. Mean (standard deviation) age at index fracture was 80.4 (8.3) years. In the year prior to index fracture, 32,772 (28.3%) patients received OP treatment. The incidence of index fractures per 1,000 persons (95% confidence interval) from 2011–2015 ranged from 15.16 (14.98–15.35) to 16.32 (16.14–16.51). Of all examined index fracture types, hip fractures occurred in the greatest proportion (27.3%) of patients (Table). The proportion of patients incurring a second fracture of any type ranged from 13.4% (tibia, fibula, knee, or foot index fracture) to 23% (vertebral index fracture). Hip fractures were the most common subsequent fracture type and the proportion of subsequent hip fractures was highest in patients with an index hip fracture (Table). The median (interquartile range [IQR]) time to second fracture ranged from 436 (69–939) days (radius and ulna index fracture) to 640 (297–1,023) days (tibia, fibula, knee, or foot index fracture). The median (IQR) time from second to third fracture ranged from 237 (75–535) days (pelvis index fracture) to 384 (113–608) days (femur index fracture).

This real-world study found that elderly patients in Ontario, Canada incurring a primary fragility fracture from 2011–2015 were at risk for future fractures occurring over shorter periods of time with each subsequent fracture. These observations are consistent with previous reports of imminent fracture risk and the fragility fracture cascade in OP patients (Balasubramanian et al. ASBMR 2016, Toth et al. WCO-IOF-ESCEO 2018). Overall, these data suggest that in elderly patients with an index fragility fracture at any site (with the exception of the radius or ulna), the most likely subsequent fracture will occur at the hip in less than 2 years.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 60 - 60
1 Jul 2020
Nowak L Schemitsch EH
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Previous studies have indicated that prolonged surgical time may lead to higher rates of infection following total hip arthroplasty (THA). The purpose of this study was to evaluate the influence of surgical time on 30-day complications following THA and to determine if there was a time interval associated with worse outcomes.

Patients ≥18 years who underwent THA between 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database using procedural codes. Patients with surgical durations >240 minutes were excluded. Patient demographics, operation length, and 30-day major and minor complications were ascertained. Multivariable regression was used to determine if the rate of complications differed depending on length of operation, while adjusting for relevant covariables, and to identify independent predictors of operation length. Covariables of interest included age, sex, American Society of Anaesthesiologists (ASA) class, smoking status, functional status, comorbidities, anesthesia type, and Body Mass Index (BMI).

A total of 131,361 THA patients (average age 65 ±12 years) were identified from the database. Of these, 2,177 (1.64%) experienced a major complication, and 3,504 (2.64%) experienced a minor complication within 30-days of the initial procedure. Average operation length was 91.9 minutes (range 20 – 240 minutes). Independent predictors of prolonged operation length included overweight/obese BMI, male sex, cancer, dependent functional status, epidural anaesthetic, lower pre-operative hematocrit, and ASA class II, III or IV vs. I Alternatively, older age, current smoking, and spinal anaesthetic were associated with shorter surgical durations.

Unadjusted rates of both major and minor complications were significantly higher for patients whose operation lengths were ≥ 120 minutes (P>0.001). Specifically, patients whose operations lasted ≥ 120 minutes had higher rates of septic shock, sepsis, pulmonary embolism (PE), deep vein thrombosis (DVT), urinary tract infection (UTI), renal insufficiency, surgical site infection(SSI) and wound disruption. After covariable adjustment, surgical durations of 90–119 minutes increased the risk of minor complications by 1.2 (95%Confidence interval [95%CI] 1.1–1.3), while surgical durations of 120–179 minutes increased the risk of major complications by 1.4 (95%CI 1.3 – 1.6), and minor complications by 1.4 (95%CI 1.2 – 1.5), and surgical durations ≥180 minutes increased the risk of major complications by 2.1 (95%CI 1.8 – 2.6), and minor complications by 1.9 (95%CI 1.6 – 2.3). There was no difference in the overall risk of complications for operation times lasting 20 – 39, 40 – 59, or 60 – 89 minutes (P>0.05).

In terms of specific complications, operation length ≥90 minutes was determined to be an independent risk factor for deep and superficial incisional SSI, as well as wound disruption, while operation length ≥ 120 minutes was an independent risk factor for sepsis, UTI, and deep, non-incisional SSI and operation length ≥ 180 minutes was an independent risk factor for PE, DVT, and cardiac arrest (p < 0 .05). These data indicate that prolonged surgical durations may be an independent predictor of major and minor complications following THA. This suggests that quality improvements could be made to improve operating room efficiency and surgical times and therefore postoperative outcomes.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 147 - 147
1 Jul 2020
Godbout C Nauth A Schemitsch EH Fung B Lad H Watts E Desjardins S Cheung KLT
Full Access

The Masquelet or induced membrane technique (IMT) is a two-stage surgical procedure used for the treatment of segmental bone defects. In this technique, the defect is first filled with a polymethyl methacrylate (PMMA) spacer, which triggers the formation of a membrane that will encapsulate the defect. During the second surgery, the spacer is carefully removed and replaced by autologous bone graft while preserving the membrane. This membrane is vascularized, contains growth factors, and provides mechanical stability to the graft, all of which are assumed to prevent graft resorption and promote bone healing.

The technique is gaining in popularity and several variations have been introduced in the clinical practice. For instance, orthopaedic surgeons now often include antibiotics in the spacer to treat or prevent infection. However, the consequences of this approach on the properties of the induce membrane are not fully understood. Accordingly, in a small animal model, this study aimed to determine the impact on the induced membrane of impregnating spacers with antibiotics frequently used in the IMT.

We surgically created a five-mm segmental defect in the right femur of 25 adult male Sprague Dawley rats. The bone was stabilized with a plate and screws before filling the defect with a PMMA spacer. Animals were divided into five equal groups according to the type and dose of antibiotics impregnated in the spacer: A) no antibiotic (control), B) low-dose tobramycin (1.2 g/40 g of PMMA), C) low-dose vancomycin (1 g/40 g of PMMA), D) high-dose tobramycin (3.6 g/40 g of PMMA), E) high-dose vancomycin (3 g/40 g of PMMA). The animals were euthanized three weeks after surgery and the induced membranes were collected and divided for analysis. We assessed the expression of selected genes (Alpl, Ctgf, Runx2, Tgfb1, Vegfa) within the membrane by quantitative real-time PCR. Moreover, frozen sections of the specimens were used to quantify vascularity by immunohistochemistry (CD31 antigen), proliferative cells by immunofluorescence (Ki-67 antigen), and membrane thickness. Microscopic images of the entire tissue sections were taken and analyzed using FIJI software. Finally, we measured the concentration of vascular endothelial growth factor (VEGF) in the membranes by ELISA.

No significant difference was found among the groups regarding the expression of genes related to osteogenesis (Alpl, Runx2), angiogenesis (Vegfa), or synthesis of extracellular matrix (Ctgf, Tgfb1) (n = four or five). Similarly, the density of proliferative cells and blood vessels within the membrane, as well as the membrane thickness, did not vary substantially between the control, low-dose, or high-dose antibiotic groups (n = four or five). The concentration of VEGF was also not significantly influenced by the treatment received (n = four or five).

The addition of tobramycin or vancomycin to the spacer, at the defined low and high doses, does not significantly alter the bioactive characteristics of the membrane. These results suggest that orthopaedic surgeons could use antibiotic-impregnated spacers for the IMT without compromising the induced membrane and potentially bone healing.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 16 - 16
1 Oct 2019
Nowak L Schemitsch EH
Full Access

Introduction

We designed this study to compare 30-day complications and length of hospital stay between patients undergoing total knee arthroplasty (TKA) with general anesthesia, to those undergoing TKA with spinal, epidural anesthesia, or Monitored Anesthesia Care (MAC, a combination of local anesthesia with sedation and analgesia provided by an anesthesiologist) with or without regional nerve blocks.

Methods

We identified patients ≥18 years undergoing TKA between the years of 2006 and 2017 from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). We collected patient demographics, anesthesia type, 30-day complications, length of operation and hospital stay from the database. We used multivariable regression to compare complications and length of stay (LOS) between anesthesia types, while adjusting for relevant covariables


The Bone & Joint Journal
Vol. 101-B, Issue 10 | Pages 1272 - 1279
1 Oct 2019
Nowak LL Hall J McKee MD Schemitsch EH

Aims

To compare complication-related reoperation rates following primary arthroplasty for proximal humerus fractures (PHFs) versus secondary arthroplasty for failed open reduction and internal fixation (ORIF).

Patients and Methods

We identified patients aged 50 years and over, who sustained a PHF between 2004 and 2015, from linkable datasets. We used intervention codes to identify patients treated with initial ORIF or arthroplasty, and those treated with ORIF who returned for revision arthroplasty within two years. We used multilevel logistic regression to compare reoperations between groups.


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 70 - 76
1 Jul 2019
Nowak LL Schemitsch EH

Aims

To evaluate the influence of discharge timing on 30-day complications following total knee arthroplasty (TKA).

Patients and Methods

We identified patients aged 18 years or older who underwent TKA between 2005 and 2016 from the American College of Surgeons’ National Surgical Quality Improvement Program (NSQIP) database. We propensity score-matched length-of-stay (LOS) groups using all relevant covariables. We used multivariable regression to determine if the rate of complications and re-admissions differed depending on LOS.


The Bone & Joint Journal
Vol. 101-B, Issue 6_Supple_B | Pages 51 - 56
1 Jun 2019
Nowak LL Schemitsch EH

Aims

The aim of this study was to assess the influence of operating time on 30-day complications following total hip arthroplasty (THA).

Patients and Methods

We identified patients aged 18 years and older who underwent THA between 2006 and 2016 from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. We identified 131 361 patients, with a mean age of 65 years (sd 12), who underwent THA. We used multivariable regression to determine if the rate of complications and re-admissions was related to the operating time, while adjusting for relevant covariables.


The Bone & Joint Journal
Vol. 100-B, Issue 3 | Pages 361 - 369
1 Mar 2018
Sprague S Bhandari M Heetveld MJ Liew S Scott T Bzovsky S Heels-Ansdell D Zhou Q Swiontkowski M Schemitsch EH

Aims

The primary aim of this prognostic study was to identify baseline factors associated with physical health-related quality of life (HRQL) in patients after a femoral neck fracture. The secondary aims were to identify baseline factors associated with mental HRQL, hip function, and health utility.

Patients and Methods

Patients who were enrolled in the Fixation using Alternative Implants for the Treatment of Hip Fractures (FAITH) trial completed the 12-item Short Form Health Survey (SF-12), Western Ontario and McMaster Universities Arthritis Index, and EuroQol 5-Dimension at regular intervals for 24 months. We conducted multilevel mixed models to identify factors potentially associated with HRQL.


The Bone & Joint Journal
Vol. 99-B, Issue 12 | Pages 1590 - 1595
1 Dec 2017
Atrey A Ward SE Khoshbin A Hussain N Bogoch E Schemitsch EH Waddell JP

Aims

We present the ten-year data of a cohort of patients, aged between 18 and 65 years (mean age 52.7 years; 19 to 64), who underwent total hip arthroplasty. Patients were randomised to be treated with a cobalt-chrome (CoCr) femoral head with an ultra-high molecular weight polyethylene (UHMWPE), highly cross-linked polyethylene (XLPE) or ceramic-on-ceramic (CoC) bearing surface.

Patients and Methods

A total of 102 hips (91 patients) were randomised into the three groups. At ten years, 97 hips were available for radiological and functional follow-up. Two hips (two patients) had been revised (one with deep infection and one for periprosthetic fracture) and three were lost to follow-up. Radiological analysis was performed using a validated digital assessment programme to give linear, directional and volumetric wear of the two polyethylene groups.


The Bone & Joint Journal
Vol. 98-B, Issue 9 | Pages 1175 - 1179
1 Sep 2016
Olsen M Lewis PM Morrison Z McKee MD Waddell JP Schemitsch EH

Aims

One method of femoral head preservation following avascular necrosis (AVN) is core decompression and insertion of a tantalum rod. However, there may be a high failure rate associated with this procedure. The purpose of this study was to document the clinical and radiological outcomes following total hip arthroplasty (THA) subsequent to failed tantalum rod insertion.

Patients and Methods

A total of 37 failed tantalum rods requiring total hip arthroplasty were identified from a prospective database. There were 21 hips in 21 patients (12 men and nine women, mean age 37 years, 18 to 53) meeting minimum two year clinical and radiographic follow-up whose THAs were carried out between November 2002 and April 2013 (mean time between tantalum rod implantation and conversion to a THA was 26 months, 6 to 72). These were matched by age and gender to individuals (12 men, nine women, mean age 40 years, 18 to 58) receiving THA for AVN without prior tantalum rod insertion.


The Bone & Joint Journal
Vol. 95-B, Issue 4 | Pages 517 - 522
1 Apr 2013
Henry PDG Dwyer T McKee MD Schemitsch EH

Latissimus dorsi tendon transfer (LDTT) is technically challenging. In order to clarify the local structural anatomy, we undertook a morphometric study using six complete cadavers (12 shoulders). Measurements were made from the tendon to the nearby neurovascular structures with the arm in two positions: flexed and internally rotated, and adducted in neutral rotation. The tendon was then transferred and measurements were taken from the edge of the tendon to a reference point on the humeral head in order to assess the effect of a novel two-stage release on the excursion of the tendon.

With the shoulder flexed and internally rotated, the mean distances between the superior tendon edge and the radial nerve, brachial artery, axillary nerve and posterior circumflex artery were 30 mm (26 to 34), 28 mm (17 to 39), 21 mm (12 to 28) and 15 mm (10 to 21), respectively. The mean distance between the inferior tendon edge and the radial nerve, brachial artery and profunda brachii artery was 18 mm (8 to 27), 22 mm (15 to 32) and 14 mm (7 to 21), respectively. Moving the arm to a neutral position reduced these distances. A mean of 15 mm (8 to 21) was gained from a standard soft-tissue release, and 32 mm (20 to 45) from an extensile release.

These figures help to define further the structural anatomy of this region and the potential for transfer of the latissimus dorsi tendon.

Cite this article: Bone Joint J 2013;95-B:517–22.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 11 - 11
1 Sep 2012
Sheth U Simunovic N Klein G Fu F Einhorn T Schemitsch EH Ayeni O Bhandari M
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Purpose

The recent emergence of autologous blood concentrates, such as platelet rich plasma (PRP), as a treatment option for patients with orthopaedic injuries has led to an extensive debate about their clinical benefit. Our objective was to determine the effectiveness of autologous blood concentrates compared with control therapy in improving pain in patients with orthopaedic bone and soft tissue injuries.

Method

We conducted a systematic review of MEDLINE and EMBASE from 1996 and 1947, respectively, up to July 2010. Additional studies were identified by contacting experts, searching the bibliographies of the included studies as well as orthopaedic meeting archives. We included published and unpublished randomized controlled trials or prospective cohort studies that compared autologous blood concentrates with a control therapy in patients with an orthopaedic injury. Two reviewers, working in duplicate, abstracted data on study characteristics and protocol. Reviewers resolved disagreement by consensus.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 43 - 43
1 Sep 2012
Olsen M Edwards M Sellan M Crookshank MC Bristow L Schemitsch EH
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Purpose

Computer navigation for hip resurfacing has been shown to reduce the incidence of technical error during femoral head preparation and provides increased accuracy compared to conventional instrumentation for insertion of the initial femoral guidewire. Limitations to the widespread use of navigation in hip resurfacing include access and cost. A novel, patient specific nylon jig has been developed as a cost effective alternative for placement of the initial guidewire. The purpose of this study was to compare the accuracy of femoral guidewire insertion between imageless navigation, conventional instrumentation and a new type of CT-based custom jig.

Method

Six pairs of cadaveric femora were used in the study. Each pair was divided randomly between a group utilizing firstly a conventional lateral pin jig (BHR, Smith & Nephew Inc.) followed by navigation (Vector Vision SR, BrainLAB) and a group utilizing a CT-based, patient specific custom jig (Visionaire, Smith & Nephew Inc.). A single surgeon inserted all guidewires. The planned guidewire position was approximately 10 degrees of relative valgus to the native neck-shaft angle in the coronal plane and neutral version in the sagittal plane. The same coronal alignment angle was used between paired femora. Femurs were positioned in a draped synthetic foam hip model prepared with a standard posterior approach. Guidewire insertion time and placement accuracy for each of the three alignment methods was assessed. Guidewire placement accuracy for coronal inclination and version was assessed by anteroposterior and lateral digital radiographs and was defined as the mean deviation from the planned alignment value.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 70 - 70
1 Sep 2012
Schemitsch EH Investigators S Sanders DW
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Purpose

There is no clear definition of a critical sized defect of the tibia. We defined it as a fracture gap at least one centimeter in length and involving over 50% of the cortical diameter. We explored if the presence of a critical-sized defect predicted reoperation, and which other factors predict reoperation in patients with the critical defect. The patient based outcomes of these patients were compared to patients without a critical defect.

Method

Patients enrolled in the SPRINT trial with a critical sized defect were evaluated for secondary interventions to gain union. Other factors predicting the need for reoperation were studied. We also compared the patients with critical sized defects to the larger cohort of patients without a defect with respect to demographics, injury mechanism, fracture characteristics, and patient-based outcome.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 72 - 72
1 Sep 2012
Schemitsch EH Investigators S Bhandari M
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Purpose

Our hypothesis was that closed tibia fractures treated with intramedullary nails are impacted by surgeon and center volumes.

Method

Data from 813 patients with closed tibia fractures were obtained from the SPRINT study. Using multiple regression, we examined the effect of center and surgeon volume (categorized as high, moderate, or low), and geographic differences by country (Canada, USA, and the Netherlands) on health-related quality-of-life and revision surgeries to gain union at one year. Our measures of quality-of-life were the Short-Form 36 Health Survey Questionnaire (SF-36 PCS) and the Short Musculoskeletal Function Assessment (SMFA).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 202 - 202
1 Sep 2012
Schemitsch EH Schemitsch L Veillette C McKee MD COTS COTS
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Purpose

There is increasing evidence that primary fixation of displaced mid-shaft fractures of the clavicle results in superior short-term outcomes when compared to traditional non-operative methods. However, the results from published studies are limited to relatively short-term (one year or less) follow-up. Accurate data of longer follow-up is important for a number of reasons, including patient prognostication, counseling and care, the design of future trials, and the economic analysis of treatment. The purpose of this paper was to examine the results of the two year follow up of patients enrolled in a previously published randomized clinical trial of operative versus non-operative treatment of displaced fractures of the clavicle.

Method

Using a comprehensive and standard assessment that included DASH (Disabilities of the Arm, Shoulder and Hand) and CSS (Constant Shoulder Scores) scores, we evaluated ninety-five patients of the original cohort of one hundred and thirty-two patients at two years following their injury.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 161 - 161
1 Sep 2012
Waddell JP Edwards M Lutz M Keast-Butler O Escott B Schemitsch EH
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Purpose

To review prospectively collected data on patients undergoing primary total hip arthroplasty utilizing two different cementless acetabular components.

Method

All patients undergoing primary total hip replacement surgery at our institution are entered prospectively into a database which includes history and physical examination, radiology, WOMAC and SF-36 scores. The patients are re-examined, re-x-rayed and re-scored at 3 months, 6 months and 1 year after surgery and yearly thereafter.

Using this database we are able to identify patients who have undergone total hip replacement using one of two geometric variants of the acetabular component. The first design is hemispherical and the second design has a peripheral rim expansion designed to increase initial press-fit stability.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 165 - 165
1 Sep 2012
Powell JN Beaulé PE Antoniou J Bourne RB Schemitsch EH Vendittoli P Smith F Werle J Lavoie G Burnell C Belzile É Kim P Lavigne M Huk OL O'Connor G Smit A
Full Access

Purpose

The purpose of the study was to determine the rate of conversion from RSA to THR in a number of Canadian centers performing resurfacings

Method

Retrospective review was undertaken in 12 Canadian Centers to determine the rate of revision and reason for conversion from RSA to THR. Averages and cross-tabulation with Chi-Squared analysis was performed. kaplan Meier survivorship was calculated.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 160 - 160
1 Sep 2012
Kuzyk PR Saccone M Sprague S Simunovic N Bhandari M Schemitsch EH
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Purpose

Cross-linking of polyethylene greatly reduces its wear rate in hip simulator studies. We conducted a systematic review and meta-analysis of randomized controlled trials comparing cross-linked to conventional polyethylene liners for total hip arthroplasty to determine if there is a clinical reduction of: 1) wear rates, 2) radiographic osteolysis, and 3) need for total hip revision.

Method

A systematic search of MEDLINE, EMBASE, and COCHRANE databases was conducted from inception to May 2010 for all trials involving the use of cross-linked polyethylene for total hip arthroplasty. Eligibility for inclusion in the review was: use of a random allocation of treatments; a treatment arm receiving cross-linked polyethylene and a treatment arm receiving conventional polyethylene for total hip arthroplasty; and use of radiographic wear as an outcome measure. Eligible studies were obtained and read in full by two co-authors who then independently applied the Checklist to Evaluate a Report of a Nonpharmacological Trial to each study. Pooled mean differences were calculated for the following continuous outcomes: bedding-in, linear wear rate, three dimensional linear wear rate, volumetric wear rate, and total linear wear. Pooled risk ratios were calculated for radiographic osteolysis and revision hip arthroplasty.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 148 - 148
1 Sep 2012
McKee RC Whelan DB Schemitsch EH McKee MD
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Purpose

Displaced midshaft clavicular fractures are a common injury with a high occurrence rate in young, active individuals. Non-operative care has traditionally been the standard of care for such fractures, but more recent studies have suggested benefits following primary operative fixation. The purpose of this study was to review the literature on displaced midshaft clavicle fractures, identify randomized controlled trials of operative versus non-operative treatment, and pool the functional outcome and complication rates (including nonunion and symptomatic malunion), to arrive at summary estimates of these outcomes.

Method

A systematic review of the literature was performed to identify studies of randomized controlled trials comparing operative versus non-operative care for displaced midshaft clavicle fractures. Meeting abstracts were also searched and included in this study.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 2 - 2
1 Sep 2012
Li R Qamirani E Atesok K Nauth A Wang S Li C Schemitsch EH
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Purpose

Angiogenesis and osteogenesis are essential for bone growth, fracture repair, and bone remodeling. VEGF has an important role in bone repair by promoting angiogenesis and osteogenesis. In our previous study, endothelial progenitor cells (EPCs) promoted bone healing in a rat segmental bone defect as confirmed by radiological, histological and microCT evaluations (Atesok, Li, Schemitsch 2010); EPC treatment of fractures resulted in a significantly higher strength by biomechanical examination (Li, Schemitsch 2010). In addition, cell-based VEGF gene transfer has been effective in the treatment of segmental bone defects in a rabbit model (Li, Schemitsch et al 2009); Purpose of this study: Evaluation of VEGF gene expression after EPC local therapy for a rat segmental bone defect.

Method

Rat bone marrow-derived EPCs were isolated from the rat bone marrow by the Ficoll-paque gradient centrifuge technique. The EPCs were cultured for 7 to 10 days in endothelial cell growth medium with supplements (EGM-2-MV-SingleQuots, Clonetics). and collected for treatment of the rat segmental bone defect. EPCs were identified by immunocytochemistry staining with primary antibodies for CD34, CD133, FLK-1, and vWF. A total of fifty six rats were studied. A five millimeter segmental bone defect was created in the middle 1/3 of each femur followed by mini plate fixation. The treatment group received 1×106 EPCs locally at the bone defect and control animals received saline only. Seven control and seven EPC treated rats were included in each group at 1, 2, 3 and 10 weeks. Animals were sacrificed at the end of the treatment period, and specimens from the fracture gap area were collected and immediately frozen. Rat VEGF mRNA was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantified by VisionWorksLS. All measurements were performed in triplicate.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 200 - 200
1 Sep 2012
Crookshank MC Edwards M Sellan M Whyne CM Schemitsch EH
Full Access

Purpose

Femoral shaft fractures are routinely treated using antegrade intramedullary nailing under fluoroscopic guidance. Malreduction is common and can be due to multiple factors. Correct entry point identification can help minimize malreduction and the risk of iatrogenic fracture. This study aims to compare landmark identification used to guide nail entry, the piriformis fossa (PF) and the trochanteric tip (T), via computer navigation and conventional fluoroscopy.

Method

The location of the PF and T were digitized under direct visualization with a three-dimensional scribe on ten, fresh-frozen cadaveric right femora (two male, eight female) by three fellowship trained orthopaedic surgeons. To estimate inter- and intraobserver reliability of the direct measurements, an intraclass correlation coefficient was calculated with a minimum of two weeks between measurements. Under navigation, each specimen was draped and antero-posterior (AP) and lateral radiographs of the proximal femur were taken with a c-arm and image intensifier. The c-arm was positioned in a neutral position (0 for AP, 90 for lateral) and rotated in 5 increments, yielding a range of acceptable images. Images, in increments of 5, within the AP range (with a neutral lateral) were loaded into a navigation system (Stryker, MI). A single surgeon digitized the T and PF directly based on conventional fluoroscopy, and again directed by navigation, yielding two measurements per entry point per specimen. This was repeated for the lateral range. Hierarchical linear modelling and a Wilcox rank test were used to determine differences in accuracy and precision, respectively, in the identification of PF and T using computer navigation vs. conventional fluoroscopy.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 163 - 163
1 Sep 2012
Kuzyk PR Sellan M Morison Z Waddell JP Schemitsch EH
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Purpose

Femoroacetabular impingement (FAI) may contribute to the development of early onset hip osteoarthritis (OA). A cam lesion (or pistol grip deformity) of the proximal femur reduces head-neck offset resulting in cam type FAI. The alpha angle is a radiographic measurement recommended for diagnosis of cam type FAI. The purpose of this study was to determine if patients that develop end stage hip OA prior to 55 years of age have radiographic evidence of cam type FAI.

Method

The anteroposterior (AP) pelvis and lateral hip radiographs of 244 patients (261 hips) who presented to our institution for hip arthroplasty or hip fracture fixation between 2006 and 2008 were retrospectively reviewed. Three cohorts were compared: 1) patients with end stage hip OA < 55 years old (N=76); 2) patients with end stage hip OA > 55 years old (N=84); 3) hip fracture patients > 65 years old without radiographic evidence of hip arthritis were used as controls (N=101). Patients with inflammatory arthritis, avascular necrosis and post-traumatic hip OA were excluded. Alpha angles were measured on the AP pelvis and lateral radiographs by three coauthors using ImageJ 1.43 software (National Institutes of Health, USA). For patients with end stage hip OA, AP alpha angles were measured on both the hip with OA and the contralateral hip. Lateral alpha angles were measured only on the hip with OA. For patients with hip fracture, AP alpha angles were measured on the non-fractured hip and lateral alpha angles were measured on the fractured hip. A one-way ANOVA with post hoc Tukeys HSD test was used to compare the AP and lateral alpha angles for the three cohorts.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 114 - 114
1 Sep 2012
Olsen M Sellan M Zdero R Waddell JP Schemitsch EH
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Purpose

The Birmingham Mid-Head Resection (BMHR) is a bone-conserving, short-stem alternative to hip resurfacing for patients with compromised femoral head anatomy. It is unclear, however, if an uncemented, metaphyseal fixed stem confers a mechanical advantage to that of a traditional hip resurfacing in which the femoral prosthesis is cemented to the prepared femoral head. Thus, we aimed to determine if a metaphyseal fixed, bone preserving femoral component provided superior mechanical strength in resisting neck fracture compared to a conventional hip resurfacing arthroplasty.

Method

Sixteen matched pairs of human cadaveric femurs were divided evenly between specimens receiving a traditional epiphyseal fixed hip resurfacing arthroplasty (BHR) and those receiving a metaphyseal fixed BMHR. Pre-preparation scaled digital radiographs were taken of all specimens to determine anatomical parameters as well as planned stem-shaft angles and implant sizes. A minimum of 10 degrees of relative valgus alignment was planned for all implants and the planned stem-shaft angles and implant sizes were equal between femur pairs. Prior to preparation, bone mineral density scans of the femurs were obtained. Prepared specimens were potted, positioned in single-leg stance and tested to failure using a mechanical testing machine. Load-displacement curves were used to calculate construct stiffness, failure energy and ultimate failure load.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 135 - 135
1 Sep 2012
Schemitsch EH Investigators S
Full Access

Purpose

The SPRINT trial randomized 1226 patients with tibial shaft fractures treated by intramedullary (IM) nailing to reamed versus unreamed groups. Using data from this trial, we completed a subgroup analysis of those patients who required two or more reoperations following the initial IM fracture stabilization.

Method

We identified 44 patients with tibial shaft fractures who required two or more reoperations following IM nailing. We considered those that were reamed vs unreamed, open vs closed, those that were planned for reoperation after the 12 month follow up, and the indications for reoperation.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVIII | Pages 107 - 107
1 Sep 2012
Waddell JP Nikolaou V Edwards M Bogoch E Schemitsch EH
Full Access

Purpose

This prospective randomised controlled trial aims to compare the clinical and radiological outcomes of ceramic on ceramic, cobalt chrome on ultra-high molecular weight polyethylene, and cobalt chrome on highly cross-linked polyethylene bearing surfaces at a minimum of five years.

Method

One hundred and two primary total hip replacements were performed in ninety one patients between February 2003 and March 2005. All patients were younger than 65 (mean 52.7, 19–64). They were randomised to receive one of the three bearing surfaces. All patients had 28mm articulations with a Reflection uncemented acetabular component and a Synergy stem (Smith & Nephew, Memphis, Tennessee). Patients were followed up periodically up to at least sixty months following surgery. Outcome measures included WOMAC and SF12 scores. Radiological assessment included implant position, evidence of osteolysis and measurement of linear wear.


The Journal of Bone & Joint Surgery British Volume
Vol. 94-B, Issue 4 | Pages 459 - 465
1 Apr 2012
Nikolaou VS Edwards MR Bogoch E Schemitsch EH Waddell JP

The ideal bearing surface for young patients undergoing total hip replacement (THR) remains controversial. We report the five-year results of a randomised controlled trial comparing the clinical and radiological outcomes of 102 THRs in 91 patients who were <  65 years of age. These patients were randomised to receive a cobalt–chrome on ultra-high-molecular-weight polyethylene, cobalt–chrome on highly cross-linked polyethylene, or a ceramic-on-ceramic bearing. In all, 97 hip replacements in 87 patients were available for review at five years. Two hips had been revised, one for infection and one for peri-prosthetic fracture.

At the final follow-up there were no significant differences between the groups for the mean Western Ontario and McMaster Universities osteoarthritis index (pain, p = 0.543; function, p = 0.10; stiffness, p = 0.99), Short Form-12 (physical component, p = 0.878; mental component, p = 0.818) or Harris hip scores (p = 0.22). Radiological outcomes revealed no significant wear in the ceramic group.

Comparison of standard and highly cross-linked polyethylene, however, revealed an almost threefold difference in the mean annual linear wear rates (0.151 mm/year versus 0.059 mm/year, respectively) (p < 0.001).


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 561 - 561
1 Nov 2011
Walmsley DW Peskun C Waddell JP Schemitsch EH
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Purpose: There is growing support in the medical literature that patient outcomes are adversely affected by physician fatigue in operator-dependent cognitive and technical tasks. The recent increase in total joint arthroplasty case load has resulted in longer operative days and increased surgeon fatigue. The purpose of this study was to determine if time of day predicts perioperative outcomes and complications in total hip and knee arthroplasty surgery.

Method: The records of all primary Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA) surgery performed for primary osteoarthritis, during 2007 at one large university hospital, were retrospectively reviewed. Complete demographic data (age, gender, Body Mass Index), start time of surgery, intraoperative complications, duration of surgery, radiographic component alignment, and functional outcome scores (SF-12 and WOMAC) for 341 THA and 292 TKA patients were collected and analyzed using linear and nonparametric rank correlation statistics. Data was corrected for gender, body mass index (BMI), surgeon, and post-call operating days.

Results: In the THA cohort, a later start time of surgery was significantly related to duration of surgery (p=0.0013). In addition, there was a trend towards significance for intraoperative femur fracture (p=0.0542) later in the day. Postoperative complications, component alignment, and functional outcome scores were not significantly affected by start time of surgery. There were no significant findings for any of the intraoperative or postoperative outcomes in the TKA cohort.

Conclusion: This study demonstrates that duration of surgery and the incidence of intraoperative complications for THA may increase as the start time of surgery becomes later in the day. These findings should be taken into consideration when planning operative days involving THA.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 567 - 567
1 Nov 2011
Beaulé PE Smith F Powell JN Antoniou J Bourne RB Lavigne M Belzile E Schemitsch EH Garbuz D
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Purpose: Recently, there has been concern raised on the occurrence of pseudotumors after metal on metal hip resurfacing. A pseudotumor is defined as a local soft tissue mass associated with localized bony and/or tissue (muscle) destruction. The primary purpose of this study is to determine the incidence of this complication in several high volume Canadian academic centres.

Method: Nine of the 11 Canadian academic centres who perform metal on metal hip resurfacings were surveyed. The number of metal on metal hip resurfacing arthroplasties performed at each centre was first determined, as were the number of those who have presented with a pseudotumour, and subsequently gone on to revision surgery. The basic demographics of the group were recorded, as were the radiographic and implant design variables for those cases presenting with a pseudotumour.

Results: A sample of 3,400 hip resurfacing arthroplasties performed between 2002 and December 2008 were surveyed. Demographics were tabulated for a sub-sample of these patients. 76% were male, the mean length of follow-up was 3.02 years, mean BMI was 28.65, and mean age was 52.10 years. Three of 3,400 cases presented with a pseudotumour, an incidence of .09%.

Conclusion: Although pseudotumors remain a concern after metal on metal hip resurfacing, the incidence at short to mid term follow-up is very low in this multi-centre academic survey. This information is significantly lower than what other groups have recently reported. Continued close monitoring is required in order to determine what clinical factors are at play.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 577 - 577
1 Nov 2011
Morison Z Higgins GA Olsen M Lewis PM Schemitsch EH
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Purpose: Surgeons performing hip resurfacing antevert and translate the femoral component anteriorly to maximize head/neck offset and reduce impingement. The anterior femoral neck is under tensile forces during gait similarly to the superior neck [6]. This study was designed to determine the risk of femoral neck fracture after anterior or posterior notching of the femoral neck.

Method: Forty seven fourth generation synthetic femora were implanted with Birmingham Hip Resurfacing prostheses (Smith & Nephew Inc. Memphis, USA). Implant preparation was performed using imageless computer navigation (VectorVision SR 1.0, BrainLAB, Germany). The prosthesis was initially planned for neutral version and translated anterior, or posterior, to create a femoral neck notch. The femora were fixed in a single-leg stance and tested with axial compression using a mechanical testing machine. This method enabled comparison with previously published data. The synthetic femora were prepared in eight experimental groups:two mm and five mm anterior notches, two mm and five mm posterior notches, neutral alignment with no notching (control), five mm superior notch, five mm anterior notch tested with the femur in 25° flexion and five mm posterior notch tested with the femur in 25° extension We tested the femora flexed at 25° flexion to simulate loading as seen during stair ascent. [3] The posterior five mm notched femoral necks were tested in extension to simulate sporting activities like running. The results were compared to the control group in neutral alignment using a one – way ANOVA:

Results: Testing Group Mean load to failure Significance (p-value) Anterior 2mm 3926.61 ± 894.17 .843 Anterior 5mm 3374.64 ± 345.65 .155 Neutral (Control) 4539.44 ± 786.44 – Posterior 2mm 4208.09 ± 1079.81 .994 Posterior 5mm 3988.06 ± 728.59 .902 Superior 5mm 2423.07 ± 424.17 .001 Anterior 5mm in 25° flexion 3048.11 ± 509.24 .027 Posterior 5mm in 25° extension 3104.62 ± 592.67 .038 Our data suggests that anterior and posterior two mm or five mm notches are not significantly weaker in axial compression. Anterior and posterior 5mm notches are significantly weaker in flexion/extension (p=0.027/ p=0.038). The five mm superior notch group was significantly weaker with axial compression supporting previous published data (p=0.001).

Conclusion: We conclude that anterior or posterior two mm notching of the femoral neck has no clinical implications, however five mm anterior or posterior femoral neck notching significantly weakens the femoral neck. Fracture is more likely to occur with stair ascent or activities involving weight bearing in extension. Hip resurfacing is commonly performed on active patients and five mm neck notching has clinically important implications.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 591 - 591
1 Nov 2011
Zahrai A Chahal J Stojimirovic D Yee A Schemitsch EH Kraemer W
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Purpose: Given recent evolving guidelines regarding maximum allowable work hours and emphasis on resident quality of life, novel strategies are required for implementing call schedules. The night float system has been used by some institutions as a strategy to decrease the burden of call on resident quality of life in level one trauma centres. The purpose of this study was to determine whether there are differences in quality of life, work-related stressors, and educational experience between orthopaedic surgery residents in the night float and standard call systems at two level one trauma centres.

Method: This was a prospective cohort study at two level one trauma hospitals comprised of a standard call (1 in 4) group and a night float (5pm-7am, Sunday to Friday) group for each hospital, respectively. Residents completed the Short Form 36 (SF-36) general quality-of-life questionnaire, as well as, questionnaires on stress level and educational experience before the rotation (baseline), at two, four and subsequently at six months. An analysis of covariance (ANCOVA) approach was used to compare between-group differences using the baseline scores as covariates. Wilcoxon Signed-Rank tests (non-parametric) were used to determine if the residents’ SF-36 scores were different from the age and sex matched Canadian norms. Predictors of resident quality of life were analyzed using multivariable mixed models.

Results: Seven residents were in the standard call group and nine in the night float group for a total of 16 residents (all males, mean age=35.1 yrs). Controlling for between-group differences at baseline, residents on the night float rotation had significantly lower role physical (RP), bodily pain (BP), social function (SF) subscale scores (p< 0.05).

Conclusion: Our study suggests that the residents in the standard call group had better health related quality of life in comparison with the night float group. No differences existed in subjective educational benefits and stress level between the groups. The study findings may be limited due to the small sample size. However, this sample size is substantial given the size of most orthopaedic residency programs in North America.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 575 - 575
1 Nov 2011
Bhandari M Kooistra BW Busse J Walter SD Tornetta P Schemitsch EH
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Purpose: We aimed to preliminarily validate a newly developed system, the radiographic union scale for tibial (RUST) fracture healing. We hypothesized that RUST would demonstrate better inter-rater reliability than assessment of the number of cortices bridged and correlate with functional outcomes at least as strongly as surgeon’s assessment of cortical bridging.

Method: Three blinded orthopaedic trauma surgeons independently assigned a RUST score and a number of cortices bridged by callus (zero to four) to each set of AP and lateral radiographs at each follow up period. RUST is scored from four (definitely not healed) to 12 (definitely healed) based on the presence or absence of callus and of a visible fracture line at the total of four cortices visible.

Results: For 549 sets of reviewed radiographs, inter-rater reliability for RUST scores were found to be substantially higher than for assessment of the number of cortices bridged (intra-class correlation coefficient=0.84; 95% CI, 0.80–0.87 versus kappa = 0.73; 95% CI, 0.64 – 0.81, respectively). Both methods of assessing radiographic healing were strongly correlated with weight-bearing status (r and ρ> 0.50), moderately correlated with patient-reported functional recovery and the SF-36 Physical Functioning component scores (r and ρ> 0.30), and minimally correlated with HUI Mark II scores, return to work, and the SF-36 Role Physical component and Physical Component Summary scores (r and ρ> 0.10). Neither assessment was correlated with patient-reported pain scores. All correlations were similar for RUST and the number of cortices bridged.

Conclusion: This study provides preliminary evidence that RUST can be used as a valid and reliable alternative assessment of tibial fracture healing.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 562 - 562
1 Nov 2011
Sprague S Rocca GD Dosanjh S Schemitsch EH Bhandari M
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Purpose: In recent years, there has been an increased appreciation of the importance of intimate partner violence (IPV), which is also known as domestic violence, spouse abuse, and battering, as a serious public health problem. Domestic violence is the most common cause of nonfatal injury to women in North America. As providers of musculoskeletal care and first-contact health care practitioners for many patients, orthopaedic surgeons should be knowledgeable regarding screening and possible interventions for IPV victims. The Canadian Orthopaedic Association and the American Academy of Orthopaedic Surgeons have both prepared explicit statements that orthopaedic surgeons should play a role in the screening and appropriate identification of victims of IPV. We aimed to identify the knowledge, attitudes, and beliefs about IPV among orthopaedic surgeons who are members of the Orthopaedic Trauma Association.

Method: We surveyed members of the Orthopaedic Trauma Association to identify attitudes toward IPV by posting a survey on the Orthopaedic Trauma Association website for its membership to complete. The survey consisted of three sections:

the general attitude of the orthopaedic surgeon toward intimate partner violence,

the attitude of the orthopaedic surgeon toward victims and batterers, and

the clinical relevance of intimate partner violence in orthopaedic surgery.

Results: One-hundred-and-fifty-three orthopaedic surgeons responded. The majority of the respondents were male (99%) with practices in North America (96%). Surgeons underestimated the prevalence of IPV in their practices and communities and manifested several key misconceptions:

victims must be getting something out of the abusive relationships (16%);

some women have personalities that cause the abuse (20%); and

the battering would stop if the batterer quite abusing alcohol (40%).

In the past year, approximately half of the surgeons (50.8%) acknowledged identification of a victim of IPV; however, only 4.0% of respondents currently screened for IPV among female patients with injuries. Surgeons expressed concerns about lack of knowledge in the management of abused women (30%) Guidelines for the detection and management of IPV were uncommon in most surgeons’ practices (7.8%).

Conclusion: There is a strong rationale for addressing IPV as an issue that is relevant to the field of orthopaedic surgery just as it has been shown to be relevant to primary care, emergency medicine, and obstetrics and gynecology. Our study found that orthopaedic surgeons underestimated the prevalence of IPV in their practices, held multiple misperceptions about IPV, and demonstrated discomfort in identifying and treating IPV. Targeted educational programs on IPV are needed for surgeons who routinely care for injured women.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 590 - 591
1 Nov 2011
Schemitsch EH Bhandari M
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Purpose: Intimate partner violence (IPV), also known as domestic violence, is a pattern of coercive behaviors that include repeated physical, sexual and emotional abuse. Musculoskeletal injuries are common manifestations of IPV. We aimed to determine the proportion of women presenting to orthopaedic fracture clinics for treatment of orthopaedic injuries that have experienced IPV defined as physical, sexual, or emotional abuse within the past 12 months.

Method: We completed a cross-sectional study of 282 injured women attending two Level I trauma centres in Canada. Female patients presenting to the orthopaedic fracture clinics completed two validated self-reported written questionnaires (Woman Abuse Screening Tool (WAST) and the Partner Violence Screen (PVS)) to determine the prevalence of IPV. The questionnaire also contained questions that pertain to the participant’s demographic, fracture characteristics, and experiences with health care utilization.

Results: The overall prevalence of IPV (emotional, physical, and sexual abuse) within the last 12 months was 32% (95% Confidence Interval 26.4% to 37.2%) (89 of 282 women). One in 12 injured women disclosed a history of physical abuse (24/282, 8.5%) in the past year. Seven women (2.5%) indicated the cause for their current visit was directly related to physical abuse, of which five were fractures. We did not identify any significant trends in ethnicity, socioeconomic status, or injury patterns as markers of domestic abuse. Of 24 women with physical injuries, only four had been asked about IPV by a physician, none of whom were their treating orthopaedic surgeons.

Conclusion: Our study confirms a high prevalence of IPV among female patients with injuries attending orthopaedic surgical clinics in Ontario. Similar to previous research our study found that women of all ages, ethnicities, social economic status, and injury patterns may experience IPV. Surgeons should consider screening all injured women for domestic violence in their clinics.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 566 - 566
1 Nov 2011
Kuzyk PR Higgins G Tunggal J Schemitsch EH Waddell JP
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Purpose: The purpose of this study was to evaluate the accuracy and precision of 3 common methods used to produce posterior tibial slope during total knee arthroplasty.

Method: The study population consisted of 110 total knee arthroplasties in 102 patients that underwent total knee arthroplasty. All procedures were performed using a standard medial parapatellar approach and all knees were replaced using the Scorpio Knee System (Stryker, Mahwah, NJ) of implants and instruments. Three treatment groups were identified retrospectively based on the method used to produce the posterior tibial slope. Group 1 used an extramedullary guide with a 0 degree cutting block tilted by placing 2 fingers between the tibia and the extramedullary guide proximally and three fingers between the tibia and guide distally to produce a 3 degree posterior slope (N=40). Group 2 used computer navigation (Stryker Navigation System, Stryker, Mahwah, NJ) to produce a 3 degree posterior slope (N=30). Group 3 used an extramedullary guide placed parallel to the anatomic axis of the tibia with a 5 degree cutting block to produce a 5 degree posterior slope (N=40). Posterior tibial slope was measured from lateral radiographs by 2 independent reviewers that were blinded to the treatment group. The reported posterior tibial slope for each sample was an average of these two measurements. Accuracy of the treatment group was evaluated using a one sample t test. Groups 1 and 2 were tested for an ideal slope of 3 degrees, and Group 3 was tested for an ideal slope of 5 degrees. An a priori sample size calculation with α=0.05 and β=0.20 showed that at least 24 samples in each treatment group were required to determine a difference of 1.5 degrees between the treatment group mean posterior tibial slope and the ideal posterior tibial slope.

Results: The mean posterior slope measurements for treatment Group 1 (4.15±3.24 degrees) and treatment Group 2 (1.60±1.62 degrees) were both significantly different than the ideal slope of 3 degrees (p=0.03 for Group 1 and p< 0.01 for Group 2). This indicates that treatment Groups 1 and 2 failed to accurately produce the ideal posterior tibial slope of 3 degrees. The mean posterior tibia slope of treatment Group 3 (5.00±2.87 degrees) was not significantly different than the ideal posterior tibial slope of 5 degrees (p=1.00). This indicates that Group 3 accurately produced the ideal tibial slope of 5 degrees.

Conclusion: The most accurate method to produce posterior tibial slope was the 5 degree cutting block with an extramedullary guide. Computer navigation had the lowest standard deviation and therefore was the most precise method. However, computer navigation was not as accurate in producing the desired posterior tibial slope as the extramedullary guide with the 5 degree cutting block. The manual method of producing tibial slope with an extramedullary guide and a 0 degree cutting block was the least precise method and not as accurate as the extramedullary guide with a 5 degree cutting block.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 575 - 575
1 Nov 2011
Schemitsch EH Lescheid J Zdero R Shah S Kuzyk PR
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Purpose: Optimal fixation for comminuted proximal humerus fractures is controversial. Complications using locked plates have been addressed by anatomic reduction or medial cortical support. The current study measured relative mechanical contributions of varus malalignment and medial cortical support.

Method: Forty synthetic humeri were divided into three groups, osteotomized, and fixed at 0, 10, and 20 degrees of varus malreduction with locked proximal humerus plates (AxSOS, Global model, Stryker, Mahwah, NJ, USA). This simulated mechanical medial support with the cortex intact. Axial, torsional, and shear stiffness were experimentally measured. Half of the specimens in each of the groups underwent a second osteotomy to create a segmental defect which simulated loss of medial support with the cortex removed. Axial, torsional, and shear stiffness experiments were repeated, followed by shear load to failure in 20 degrees of abduction.

Results: For isolated malreduction with the cortex intact, the repair construct at 0 degrees showed statistically equivalent or higher axial, torsional, and shear stiffness than other groups assessed. Subsequent removal of cortical support in half the specimens resulted in a drastic effect on axial, torsional, and shear stiffness at all varus angles. Repair constructs with the cortex intact at 0 and 10 degrees resulted in mean shear failure forces of 12965.4 N and 9341.1 N, respectively. These were statistically higher (p< 0.05) compared to most other groups tested. Specimens failed mainly by plate bending as the femoral head was pushed down medially and distally.

Conclusion: Anatomic reduction with the medial cortex intact was the stiffest construct after a simulated two-part fracture. This study also supports the practice of achieving medial cortical support by fixing proximal humeral fractures in varus if necessary. This may be preferable to fixing the fracture in anatomic alignment when there is a medial fracture gap.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 552 - 552
1 Nov 2011
Nauth A Schemitsch EH Li R
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Purpose: The purpose of this study was to compare the effects of two types of stem/progenitor cells on the healing of critical sized bone defects in a rat model. Endothelial Progenitor Cells (EPCs), a novel cell type with previously demonstrated effects on angiogenesis in animal models of vascular disease, were compared to both a control group of no cell therapy, and a treatment group of Mesenchymal Stem Cells (MSCs). The hypothesis was that EPCs would demonstrate both superior bone healing and angiogenesis, when compared to the control group and MSC group.

Method: EPCs and MSCs were isolated from the bone marrow of syngeneic rats by differential culture and grown ex vivo for 10 days. Subsequently the cells were harvested, seeded on a gelfoam scaffold, and implanted into a 5mm segmental defect in a rat femur that had been stabilized with a plate and screws. Bone healing was assessed radiographically and by microCT. Angiogenesis was assessed by histology and physiologically, using laser doppler to assess blood flow in the bone and soft tissues. All animal protocols were approved by and performed in accordance with the St. Michael’s Hospital Animal Care Committee. ANOVA was used to test for significant differences between the groups, and a p-value of < 0.05 was considered statistically significant.

Results: The EPC (n=14) group demonstrated radiographic evidence of healing of the bone defect as early as 2 weeks, and all specimens were radiographically healed at 6 weeks. Both the control group (n=14) and the MSC group (n=14) showed no radiographic evidence of healing at 10 weeks. MicroCT comparison of the EPC group versus the control group showed significantly greater bone volume and density at the defect site (p< 0.001). More blood vessel formation was observed in the EPC group versus the control group on histology at 2 weeks. Laser Doppler assessment showed significantly more soft tissue and bone blood flow at 2 and 3 weeks in the EPC group versus the control group (p=0.021).

Conclusion: The results of this study demonstrate that EPCs are effective as cell-based therapy for healing critical sized bone defects in a rat model. In this model EPCs demonstrated superiority to MSCs with regard to bone healing. In addition, EPCs demonstrated superior angiogenesis over controls in a rat model of fracture healing. These results strongly suggest that EPCs are effective for therapeutic angiogenesis and osteogenesis in fracture healing. There is a clinical need for effective strategies in the management of traumatic bone defects and nonunions. Investigation into the use of MSCs as an effective alternative to autologous bone grafting has failed to translate into clinical use. It is possible that EPCs are more effective at the regeneration of bone in segmental defects because of their synergistic effect on angiogenesis and osteogenesis. Further research into EPC based therapies for fracture healing is warranted.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 592 - 592
1 Nov 2011
Hoang-Kim M Bhandari M Beaton DE Schemitsch EH
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Purpose: Today, numerous functional outcome tools exist to assess the patient’s ability to carry out basic and instrumental activities of daily living. Furthermore, the increase in range of mobility measures reflect differences in rating scales, scores, administration and scoring options which make outcome results difficult to assess across trials. Because of the lack of consensus among investigators, we wanted to identify the citation patterns of the functional outcomes tools used by investigators in hip fracture RCTs. We believed that the lack of proper citation is an underlying factor in the diverse usage of outcome tools.

Method: We extracted the citations of disability tools from 59 Level 1 hip fracture RCTs. Disability was defined using the WHO classification (ICF). We excluded measures assessing body structure. The text and reference lists of the identified articles were screened in order to compile relevant literature on the instrument used in the RCT. Disability tools which were cited in the references were also compared to original development articles.

Results: Overall 68 different instruments were identified that measured disability in the hip fracture literature. According to ICF, 47 tools measured body function alone, 13 tools evaluated activity limitations and participation restriction and 8 were composite scoring systems. We found that 34.2% of the trials did not provide any citations to the tools assessing body function. In trials measuring activity and participation, 23.2% provided instrument citations. In trials using composite scoring systems, 19.4% of the trials provided instrument citations. All of the instrument citations when provided by the investigators were found to correspond to original development articles or trials.

Conclusion: The appropriate choice of a functional outcome instrument is fundamental in order to ensure that the results that are obtained reflect the patient. However, if citations of the indices and scales themselves are lacking, trial methodology and results could be informative but not replicated. In the future, we recommend that rigor in quality reporting include proper instrument citations.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 551 - 551
1 Nov 2011
Li R Atesok K Wright D Nauth A Whyne CM Schemitsch EH
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Purpose: Severe fractures damage blood vessels and disrupt circulation at the fracture site resulting in an increased risk of poor fracture healing. Endothelial progenitor cells (EPCs) are bone-marrow derived cells with the ability to differentiate into endothelial cells and contribute to neovascularization and re-endothelialization after tissue injury and ischemia. We have previously reported that EPC therapy resulted in improved radiographic healing and histological blood vessel formation in a rat fracture model. The purpose of this study was to further quantify the effects of EPC therapy with microCT and biomechanical analyses.

Method: Five-millimeter segmental defects were created and stabilized in the femora of 14 fisher 344 rats. The treatment group (n=7) received 1x106 EPCs within gelfoam locally at the area of the bone defect and control animals (n=7) received only saline-gelfoam with no cells. The formation and healing of bone after 10 weeks were asessed by radiographic, micro-CT and biomechanical analyses.

Results: Radiographically all the animals in EPC-treated group healed with bridging callus formation, whereas control group animals demonstrated radiographic non-union. Micro-CT assessment demonstrated significantly improved parameters of bone volume (35.34 to 20.68 mm3, p=0.000), bone volume density (0.24 to 0.13%, p=0.001), connectivity density (25.13 to 6.15%, p=0.030), trabecular number (1.14 to 0.51 1/mm, p=0.000), trabecular thickness (0.21 to 0.26 mm, p=0.011), trabecular spacing (0.71 to 1.88 mm, p=0.002), bone surface area (335.85 to 159.43mm, p=0.000), and bone surface to bone volume ratio (9.43 to 7.82 1/mm, p=0.013) in the defect site for the EPC group versus the control group respectively. Biomechanical testing showed that the EPC treatment group had a significantly higher torsional strength compared with the control group (EPC=164.6±27.9 Nmm, Control=29.5±3.8 Nmm; p value = 0.000). Similarly, the EPC treated fractures demonstrated significantly higher torsional stiffness versus controls (EPC=30.3±5.0 Nmm/ deg, Control=0.9±0.1 Nmm/deg; p value = 0.000). When biomechanically compared to contralateral intact limbs, the EPC treated limbs had similar torsional stiffness (p=0.996), but significantly lower torsional strength (p=0.000) and smaller angle of twist (p=0.002).

Conclusion: These results suggest that local EPC therapy significantly enhances fracture healing in an animal model. The biomechanical results show that control animals develop a mechanically unstable non-union. In contrast, EPC therapy results in fracture healing that restores the biomechanical properties of the fractured bone closer to that of intact bone.