Aims

Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we sought to determine if a difference in functional outcomes exists between monopolar and bipolar hemiarthroplasty (HA).

Aims

The aim of this study was to explore the functional results in a fitter subgroup of participants in the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial to determine whether there was an advantage of total hip arthroplasty (THA) versus hemiarthroplasty (HA) in this population.

Aims

To evaluate the impact of negative pressure wound therapy (NPWT) on the odds of having deep infections and health-related quality of life (HRQoL) following open fractures.

Aims

This study investigates head-neck taper corrosion with varying head size in a novel hip simulator instrumented to measure corrosion related electrical activity under torsional loads.

Many studies report the incidence and prevalence of surgical site infections (SSIs) following open fractures; however, there is limited information on the treatment and subsequent outcomes of superficial SSIs in open fracture patients. There is also a lack of clinical studies describing the prognostic factors that are associated with failure of antibiotic treatment (non-operative) for superficial SSI. To address this gap, we used data from the FLOW (Fluid Lavage in Open Fracture Wounds) trial to determine how successful antibiotic treatment was for superficial SSIs and to identify prognostic factors that could be predictive of antibiotic treatment failure.

This is a secondary analysis of the FLOW trial dataset. The FLOW trial included 2,445 operatively managed open fracture patients. FLOW participants who had a non-operatively managed superficial SSI diagnosed in the 12 months post-fracture were included in this analysis. Participants were grouped into two categories: 1) participants whose superficial SSI resolved with antibiotics alone and 2) participants whose SSI did not resolve with antibiotics alone (defined as requiring surgical management or SSI being unresolved at final follow-up (12-months post-fracture for the FLOW trial)). Antibiotic treatment success and the date when this occurred was defined by the treating surgeon. A logistic binary regression analysis was conducted to identify factors associated with superficial SSI antibiotic success. Based on biologic rationale and previous literature, a priori we identified 13 (corresponding to 14 levels) potential factors to be included in the regression model.

Superficial SSIs were diagnosed in168 participants within 12 months of their fracture. Of these, 139 (82.7%) had their superficial SSI treated with antibiotics alone. The antibiotic treatment was successful in resolving the superficial SSI in 97 participants (69.8%) and unsuccessful in resolving the SSI in 42 participants (30.2%). We found that superficial SSIs that were diagnosed later in follow-up were associated with failure of treatment with antibiotic alone (Odds ratio 1.05 for every week in diagnosis delay, 95% Confidence Interval 1.004–1.099; p=0.03). Age, sex, fracture severity, fracture pattern, wound size, time from injury to initial surgical irrigation and debridement were not associated with antibiotic treatment failure.

Our secondary analysis of prospectively collected FLOW data found antibiotics alone resolved superficial SSIs in 69.8% of patients diagnosed with superficial SSIs. We also found that superficial SSIs that were diagnosed earlier in follow-up were associated with successful treatment with antibiotics alone. This suggests that if superficial SSIs are diagnosed and treated promptly, there is a higher probability that they will resolve with antibiotic treatment.

The primary objectives of this study were to: 1) identify risk factors for subsequent surgery following initial treatment of proximal humerus fractures, stratified by initial treatment type; 2) generate risk prediction tools to predict subsequent shoulder surgery following initial treatment; and 3) internally validate the discriminative ability of each tool.

We identified patients ≥ 50 years with a diagnosis of proximal humerus fracture from 2004 to 2015 using linkable health datasets in Ontario, Canada. We used procedural and fee codes within 30 days of the index fracture to classify patients into treatment groups: 1) surgical fixation; 2) shoulder replacement; and 3) conservative. We used intervention and diagnosis codes to identify all instances of complication-related subsequent shoulder surgery following initial treatment within two years post fracture. We developed logistic regression models for randomly selected two thirds of each treatment group to evaluate the association of patient, fracture, surgical, and hospital variables on the odds of subsequent shoulder surgery following initial treatment. We used regression coefficients to compute points associated with each of the variables within each category, and calculated the risk associated with each point total using the regression equation. We used the final third of each cohort to evaluate the discriminative ability of the developed risk tools (via the continuous point total and a dichotomous point cut-off value for “higher” vs. “lower” risk determined by Receiver Operating Curves) using c-statistics.

We identified 20,897 patients with proximal humerus fractures that fit our inclusion criteria for analysis, 2,414 treated with fixation, 1,065 treated with replacement, and 17,418 treated conservatively. The proportions of patients who underwent subsequent shoulder surgery within two years were 13.8%, 5.1%, and 1.3%, for fixation, replacement, and conservative groups, respectively. Predictors of reoperation following fixation included the use of a bone graft, and fixation with a nail or wire vs. a plate. The only significant predictor of reoperation following replacement was poor bone quality. The only predictor of subsequent shoulder surgery following conservative treatment was more comorbidities while patients aged 70+, and those discharged home following initial presentation (vs. admitted or transferred to another facility) had lower odds of subsequent shoulder surgery. The risk tools developed were able to discriminate between patients who did or did not undergo subsequent shoulder surgery in the derivation cohorts with c-statistics of 0.75–0.88 (continuous point total), and 0.82–0.88 (dichotomous cut-off), and 0.53–0.78 (continuous point total) and 0.51–0.79 (dichotomous cut-off) in the validation cohorts.

Our results present potential factors associated with subsequent shoulder surgery following initial treatment of proximal humerus fractures, stratified by treatment type. Our developed risk tools showed good to strong discriminative ability in both the derivation and validation cohorts for patients treated with fixation, and conservatively. This indicates that the tools may be useful for clinicians and researchers. Future research is required to develop risk tools that incorporate clinical variables such as functional demands.

Unstable chest wall injuries have high rates of mortality and morbidity. These injuries can lead to respiratory dysfunction, and are associated with high rates of pneumonia, sepsis, prolonged ICU stays, and increased health care costs. Numerous studies have demonstrated improved outcomes with surgical fixation compared to non-operative treatment. However, an adequately powered multi-centre randomized controlled study using modern fixation techniques has been lacking.

We present a multi-centred, prospective, randomized controlled trial comparing surgical fixation of acute, unstable chest wall injuries with the current standard of non-operative management. Patients aged 16–85 with a flail chest (3 or more consecutive, segmental, displaced rib fractures), or severe deformity of the chest wall, were recruited from multiple trauma centers across North America. Exclusion criteria included: severe pulmonary contusion, severe head trauma, randomization>72 hours from injury, inability to perform surgical fixation within 96 hours from injury (in those randomized to surgery), fractures of the floating ribs, or fractures adjacent to the spine not amendable to surgical fixation. Patients were seen in follow-up for one year. The primary outcome was days free from mechanical ventilation in the first 28 days following injury. Secondary outcomes were days in ICU, rates of pneumonia, sepsis, need for tracheostomy, mortality, general health outcomes, pulmonary function testing, and other complications of treatment. A sample size of 206 was required to detect a difference of 2 ventilator-free days between the two groups, using a 2-tailed alpha error of 0.05 and a power of 0.80.

A total of 207 patients were recruited from 15 sites across Canada and USA, from 2011–2018. Ninety-nine patients were randomized to non-operative treatment, and 108 were randomized to surgical fixation. Overall, the mean age was 53 years, and 75% of patients were male, with 25% females. The commonest mechanisms of injury were: motor vehicle collisions (34%), falls (20%), motorcycle collisions (14%), and pedestrian injuries (11%). The mean injury severity score (ISS) at admission was 26, and patients had a mean of 10 rib fractures. Eighty-nine percent of patients had pneumothorax, 76% had haemothorax, and 54% had pulmonary contusion. There were no differences between the two groups in terms of demographics. The final results will be available and presented at the COA meeting in Halifax.

This is the largest randomized controlled trial to date, comparing surgical fixation to non-operative treatment of unstable chest wall and flail chest injuries. The results of this study will shed light on the best treatment options for patients with such injuries, help understand outcomes, and guide treatment. The final results will be available and presented at the COA meeting in Halifax.

Displaced femoral neck fractures can have devastating impacts on quality of life and patient function. Evidence for optimal surgical approach is far from definitive. The Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemi-Arthroplasty (HEALTH) trial aimed to evaluate unplanned secondary procedures following total hip arthroplasty (THA) versus hemi-arthroplasty (HA) within two years of initial surgery for displaced femoral neck fractures. Secondary objectives evaluated differences in patient function, health-related quality of life, mortality, and hip-related complications HEALTH is a large randomized controlled trial that included 1,495 patients across 81 centers in 10 countries. Patients aged 50 years or older with displaced femoral neck fractures received either THA or HA. Participants were followed for 24 months post-fracture and a Central Adjudication Committee adjudicated fracture eligibility, technical placement of prosthesis, additional surgical procedures, hip-related complications, and mortality. The primary analyses were a Cox proportional hazards model with time to the primary study endpoint as the outcome and THA versus HA as the independent variable. Using multi-level linear models with three levels (centre, patient, and time), with patient and centre entered as random effects, the effect of THA versus HA on quality of life (Short Form-12 (SF-12) and EQ-5D), function (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)), and mobility (Timed Up and Go Test (TUG)) were estimated separately.

The majority of patients were female (70.1%), 70 years of age or older (80.2%), and able to ambulate without the aid of an assistive device before their fracture (74.4%), and the injury in the majority of the patients was a subcapital femoral neck fracture (61.9%). The primary end point occurred in 57 of 718 patients (7.9%) who were randomly assigned to THA and 60 of 723 patients (8.3%) who were randomly assigned to HA (hazard ratio, 0.95; 95% confidence interval [CI], 0.64 to 1.40; p=0.79). Hip instability or dislocation occurred in 34 patients (4.7%) assigned to total hip arthroplasty and 17 patients (2.4%) assigned to hemi- arthroplasty (hazard ratio, 2.00; 99% CI, 0.97 to 4.09). Function, as measured with the total WOMAC total score, pain score, stiffness score, and function score, modestly favored THA over HA. Mortality was similar in the two treatment groups (14.3% among the patients assigned to THA and 13.1% among those assigned to HA, p=0.48). Serious adverse events occurred in 300 patients (41.8%) assigned to THA and in 265 patients (36.7%) assigned to HA.

Among independently ambulating patients with displaced femoral neck fractures, the incidence of secondary procedures did not differ significantly between patients who were randomly assigned to undergo THA and those who were assigned to undergo HA, and THA provided a clinically unimportant improvement over HA in function and quality of life over 24 months.

Aims

Using tibial shaft fracture participants from a large, multicentre randomized controlled trial, we investigated if patient and surgical factors were associated with health-related quality of life (HRQoL) at one year post-surgery.

Aims

The purpose of this study was to: review the efficacy of the induced membrane technique (IMT), also known as the Masquelet technique; and investigate the relationship between patient factors and technique variations on the outcomes of the IMT.

This study was designed to compare length of hospital stay, and 30-day major and minor complications between patients undergoing total knee arthroplasty (TKA) with general anesthesia, to those undergoing TKA with spinal or epidural anesthesia with or without regional nerve blocks.

Patients 18 years and older undergoing TKA between the years of 2005 and 2016 were identified from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP). Patient demographics, anesthesia type, length of operation and hospital stay, as well as 30-day major and minor complications were collected from the database. Patients with “primary anesthesia technique” codes for either spinal or epidural anesthesia along with “other anesthesia technique” codes for regional anesthesia were assumed to have been given a regional nerve block. Chi square tests, and analysis of variance were utilized to evaluate unadjusted differences in demographics and outcomes between anesthesia types. Multivariable regression was utilized to compare outcomes (length of stay and complications) between anesthesia types, while adjusting for age, American Society of Anesthesiologist (ASA) class, comorbidities, sex, steroid/immunosuppressant use, body mass index (BMI), diabetes, length of operation and smoking status.

A total of 214,665 TKA patients were identified (average age 67 ± 10 years). Of these, 257 (0.12%) underwent epidural anesthesia with a nerve block (EB), while 2,318 (1.08%) underwent epidural anesthesia with no block (E), 14,468 (1.08%) underwent spinal anesthesia with a block (SB), and 85,243 (39.7%) underwent spinal anesthesia with no block (S), and 112,377 (52.4%) underwent general anesthesia (G).

The unadjusted length of stay (LOS) was significantly longer in the E group (3.67 ± 5 days) compared to the G group (3.1 ± 3.9 days), while the unadjusted LOS was significantly shorter in the EB group (2.6 ± 1.2), and both SB and S groups (2.6 ± 3 and 2.9 ± 3, respectively), compared to the G group p < 0 .001. Following covariable adjustment, anesthesia type remained an independent predictor of length of stay. Compared to the G group, patients in the E group stayed 0.56 days longer (95% Confidence interval [95%CI] 0.42 – 0.71 days), while patients in the SB were discharged 0.28 days (95%CI 0.21 – 0.35 days) earlier, and those in the S group were discharged 0.06 days earlier (95%CI 0.02–0.09), (p < 0 .0001).

While the unadjusted rates of major complications were not significantly different between groups, the unadjusted rates of minor complications were higher in the E, EB, and G groups compared to the S and SB groups. Following covariable adjustment, there were no differences between groups in the risk of minor complications.

In conclusion, these data indicate that anesthesia type following TKA is associated with length of hospital stay, but not with 30-day complications. After adjusting for relevant covariables, patients who received epidural anesthesia without a nerve block for TKA were discharged later, while patients who received spinal anesthesia, both with and without a nerve block for TKA were discharged earlier, compared to patients who received general anesthesia for TKA.

This study was designed to compare atypical hip fractures with a matched cohort of standard hip fractures to evaluate the difference in outcomes.

Patients from the American College of Surgeons National Surgical Quality Improvement Program's (NSQIP) targeted hip fracture data file (containing a more comprehensive set of variables collected on 9,390 specially targeted hip fracture patients, including the differentiation of atypical from standard hip fractures) were merged with the standard 2016 NSQIP data file. Atypical hip fracture patients aged 18 years and older in 2016 were identified via the targeted hip fracture data file and matched to two standard hip fracture controls by age, sex, and fracture location. Patient demographics, length of hospital stay, 30-day mortality, major and minor complications, and other hip-specific variables were identified from the database. Binary outcomes were compared using the McNemar's test for paired groups, and continuous outcomes were compared using a paired t-test.

Ninety-five atypical hip fractures were identified, and compared to 190 age, sex, and fracture location matched standard hip fracture controls. There was no statistical difference in body mass index (BMI), race, ASA score, smoking status, timing of fixation, or functional status between the two groups (P>0.05). Thirty-day mortality was significantly higher in the atypical hip fracture group (atypical 7.36%, standard 2.11% p

This is the first study, to our knowledge, that demonstrates an increase in the rate of mortality in atypical hip fractures. Comparing atypical hip fractures with a matched cohort of standard hip fractures revealed a significantly greater 30-day mortality rate with an odds ratio of 3.62 in atypical hip fractures (95% CI 1.03–12.68). Prospective, clinical studies are recommended to further investigate these findings.

Tibial cut is a crucial step in ensuring adequate and appropriate proximal tibial resection for mechanical orientation and axis in total knee replacement. We evolved the concept and technique of Condylar Differential for planned tibial cuts in conventional total knee replacement, which accounts for individual variations and reflects individual mechanical orientation and alignment.

We used Condylar Differential in 37 consecutive total knee replacements including valgus knees and severe advanced osteoarthritis. First a vertical line is drawn on digital weight bearing anteroposterior radiograph for mechanical axis of tibia. Then a horizontal line is drawn across and perpendicular to the mechanical axis. The distances between the horizontal line and the lowest reproducible points of articular surfaces of medial and lateral tibial condyles respectively are measured. The difference between two measurements obviously represents Condylar Differential. Condylar Differential, adjusted to the nearest millimetre, is maintained in executing tibial cuts, successively if necessary.

Condylar Differential measurement showed a very wide variation, ranging from 8–6 (2 mm) to 10-0 (10 mm). We found that prior measurement of Condylar Differential is a simple, consistent and effective estimate and individualises the tibial cut for optimal templating of tibia. We encountered no problems, adopting this technique, in our series.

Condylar Differential contributes to optimal individualised tibial cut in conventional total knee replacement and is a useful alternative to computer navigated option with comparable accuracy in this respect. While we used the technique in digitised radiographs, this technique can also be applied to plain films, allowing for magnification.

Background

Mechanics and kinematics of the knee following total knee replacement are related to the mechanics and kinematics of the normal knee. Restoration of neutral alignment is an important factor affecting the long-term results of total knee replacement. Tibial cut is a vital and crucial step in ensuring adequate and appropriate proximal tibial resection, which is essential for mechanical orientation and axis in total knee replacement. Tibial cut must be individually reliable, reproducible, consistent and an accurate predictor of individual anatomical measurements. Conventional tibial cuts of tibia with fixed measurements cannot account for individual variations. While computer navigated total knee replacement serves as a medium to achieve this objective, the technology is not universally applicable for differing reasons. Therefore we evolved the concept and technique of Condylar Differential for planned tibial cuts in conventional total knee replacement, which accounts for individual variations and reflects the individual mechanical orientation and alignment.

Introduction

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.

Introduction

This study was designed to evaluate the effect of discharge timing on 30-day major and minor complications in patients undergoing total knee arthroplasty (TKA) while adjusting for other variables.

Aims

The Fluid Lavage in Open Fracture Wounds (FLOW) trial was a multicentre, blinded, randomized controlled trial that used a 2 × 3 factorial design to evaluate the effect of irrigation solution (soap versus normal saline) and irrigation pressure (very low versus low versus high) on health-related quality of life (HRQL) in patients with open fractures. In this study, we used this dataset to ascertain whether these factors affect whether HRQL returns to pre-injury levels at 12-months post-injury.

Proximal humerus fractures are a common fragility fracture in older adults. A variety of treatment options exist, yet longer term outcomes of newer surgical treatments have not been extensively researched. Additionally, intermediate term outcomes following both surgical and non-surgical initial treatment of these injuries have not been evaluated at a population level. The purpose of this study was to utilise administrative data from Ontario, Canada to evaluate intermediate term outcomes following initial treatment of proximal humerus fractures.

We used data from the Canadian Institute for Health Information to identify all patients aged 50 and older who presented to an ambulatory care facility with a “main diagnosis” of proximal humerus fracture from April 1, 2004 to March 31, 2013. Intervention codes from the Discharge Abstract Database were used to categorise patients into fixation, replacement, reduction or non-surgically treated groups. We used intervention codes to identify instances of complication-related operations following initial treatment (including fixation, replacement, hardware removal, rotator cuff repair and irrigation and debridement [I&D]) at one year post initial treatment.

The majority of patients (28,369, 86.6%, 95% confidence interval [95% CI] 86.2–87.0%) were initially treated non-surgically, while 2835 (8.7%, 95% CI 8.4–9.0%) underwent initial fixation, 1280 (3.9%, 95% CI 3.7–4.1%) received primary joint replacement, and 276 (0.8%, 95% CI 0.8–1.0%) were initially treated with a reduction procedure. In the year following the initial treatment period, 127 (0.4%, 95%CI 0.4–0.5%) non-surgically treated patients underwent a replacement surgery, 292 (1.0%, 95%CI 0.9–1.2%) underwent fixation, and 12 (0.04%, 95% CI 0.02–0.07%) underwent a reduction procedure. Of the 2835 patients who received initial fixation, 57 (2.0%, 95% CI 1.6–2.6%) returned for a shoulder replacement, 80 received secondary fixation (2.8%, 95% CI 2.3–3.5%), 57 (2.0%, 95%CI 1.6–2.6%) underwent rotator cuff repair, 300 (10.6%, 95% CI 9.5–11.8%) had their implants removed, and 16 (0.6%, 95% CI 0.4–0.9%) returned for I&D. Of the 1280 patients who underwent initial replacement surgeries, 30 (2.3%, 95% CI 1.7–3.3%) returned for a secondary replacement, nine (0.7%, 95% CI 0.4–1.3%) underwent rotator cuff repair, and seven (0.6%, 95% CI 0.3–1.1%) had their implant removed. In the group who received initial reduction, eight (2.9%, 95% CI 1.5–5.6%) underwent a fixation procedure, six (2.2%, 95% CI 1.0–4.7%) received replacement surgeries, and five (1.8%, 95% CI 0.8–4.2%) each received rotator cuff repair and I&D in the year following initial treatment.

The majority of proximal humerus fractures in patients 50 and older in Ontario, Canada are treated non-surgically. Complication-related operations in the year following initial non-operative treatment are relatively low. The most commonly observed procedure following initial fixation surgery is hardware removal.

Proximal femur fractures are increasing in prevalence, with femoral neck (FN) and intertrochanteric (IT) fractures representing the majority of these injuries. The salvage procedure for failed open reduction internal fixation (ORIF) is often a conversion to total hip arthroplasty (THA). The use of THA for failed ORIF improves pain and function, however the procedure is more challenging. The aim of this study was to investigate the clinical and radiographic outcomes in patients who have undergone THA after ORIF.

This retrospective case-control study compared patients who underwent THA after failed ORIF to a matched cohort undergoing primary THA for non-traumatic osteoarthritis. From 2004 to 2014, 40 patients were identified. The matched cohort was matched for date of operation, age, gender, and type of implant. Preoperative, intraoperative, and postoperative data were collected and statistical analysis was performed.

The cohort of patients with a salvage THA included 18 male and 22 female patients with a mean age of 73 years and mean follow up of 3.1 years. Those with failed fixation included 12 IT fractures and 28 FN fractures. The mean time between ORIF and THA was 2.1 years for IT fractures and 8.5 years for FN fractures (p=0.03). The failed fixation group had longer procedures, greater drop in hemoglobin, and greater blood transfusion rate (p<0.05). There was one revision and one dislocation in the failed fixation group with no revisions or dislocations in the primary THA group. Length of admission, medical complications, and functional outcome as assessed with a standardised hip score and were found not to be statistically different between the groups.

Salvage THA for failed initial fixation of proximal femur fractures yields comparable clinical results to primary THA with an increased operative time, blood loss, and blood transfusion rate.

Modular total hip arthroplasty (MTHA) stems were introduced in order to provide increased intra-operative flexibility for restoring hip biomechanics, improving stability and potentially reducing revision risk. However, the additional interface at the neck-body junction provides another location for corrosion or mechanical failure of the stem. To delineate the mid term revision risk of MTHA stems, we examined data from the Canadian Joint Replacement Registry (CJRR) at the Canadian Institute for Health Information (CIHI).

Kinectiv, Profemur and Rejuvenate modular stems were identified from CJRR records submitted between 2004 and 2014. Revision status was determined by examining the discharge abstract database (DAD) also housed by CIHI, which collects information on all revisions, regardless of whether the procedure was submitted to CJRR.

A total of 2446 modular stems were identified with a mean follow up of 4.2 years (range 0 to 10). Their usage peaked in 2012 (the first year of mandatory CJRR form submission for BC, ON and MB), and dropped rapidly thereafter. A total of 155 (6.3%) were revised. This consisted of 5/301 Kinectiv (1.7%), 141/2050 ProFemur (6.9%), and 9/96 Rejuvenate (9.4%) stems. As a group, this falls below the National Institute for Clinical Excellence (NICE) guidelines of 95% survival at 10 years.

While MTHA stems were introduced to improve outcomes and reduce revision risk, our findings of a 6.3% revision risk at a mean follow up of 4.2 years does not appear to support this.

The purpose of this study was to examine the utility of the acetabular component introducer as a tool to intra-operatively predict implant inclination in total hip arthroplasty. This study investigated (1) the correlation between intra-operative photographic assessment of cup inclination using the acetabular introducer and that measured on post-operative radiograph; and (2) the accuracy of intra-operative prediction of abduction angle.

For this study, we prospectively recruited 56 patients scheduled to receive primary hip arthroplasty from one of two senior surgeons. During the procedure, the lead surgeon provided a prediction of the abduction angle based on the alignment of the impactor attached to the cup in its final seated position. A standardized anteroposterior (AP) photograph was then taken of the acetabular impactor in situ. Abduction angles were measured by two observers on the photographs and post-operative AP pelvis radiographs. Linear regression was used to determine the correlation between the angle of the guide measured on the photographs and the actual position of the implant measured on the radiograph. Descriptive statistics were further used to analyze the accuracy of the intra-operative prediction as compared with the abduction angle measured on the photographs.

Measurements of cup position made from post-operative radiographs were significantly correlated with the measurements as assessed by intra-operative photographs (r = 0.34, p = 0.00). Our findings demonstrate that radiological abduction angles tend to be greater than that assessed by intra-operative photographs by a mean of 5.6 degrees (SD = 6.6 degrees; 95% CI = 7.3 to 3.9 degrees). Conversely, surgeon prediction of cup inclination based on the acetabular introducer differed from the radiographic measurements by a mean of 6.8 degrees (SD = 8.7 degrees). There was good agreement between the two observers in both photographic and radiographic measurement (k = 0.95, k = 0.96, respectively).

In conclusion, we found that the intra-operative photographic assessment of acetabular cup inclination by acetabular impactor alignment tends to underestimate the abduction angle by a mean of approximately 5 degrees. In addition, intra-operative surgeon estimation of acetabular inclination did not appear accurate in this study demonstrating that cup position should rely on additional visual cues beyond that captured in the anteroposterior view of the cup introducer.

Introduction:

One method of femoral head preservation following avascular necrosis (AVN) is core decompression and Tantalum Rod insertion. There is, however, a published failure rate of up to 32% at 4 years. The purpose of the present study was to document the clinical and radiological outcome following Total Hip Arthroplasty (THA) subsequent to failed Tantalum Rod insertion.

Introduction:

Alignment of the initial femoral guidewire is critical in avoiding technical errors that may increase the risk of failure of the femoral component. A novel alternative to conventional instrumentation for femoral guidewire insertion is a computed tomography (CT) based alignment guide. The aim of this study was to assess the accuracy of femoral component alignment using a CT-based, patient specific femoral alignment guide.

Purpose:

The use of computer navigation has been shown to improve the accuracy of femoral component placement compared to conventional instrumentation in hip resurfacing. Whether exposure to computer navigation improves accuracy when the procedure is subsequently performed with conventional instrumentation without navigation has not been explored. We examinedwhether femoral component alignment utilizing a conventional jig improves following experience with the use of imageless computer navigation for hip resurfacing.

Introduction

There has been a paradigm shift in orthopaedic research, it is now recognized that the extent to which interventions really make a difference to a patient's overall life is indicated by measuring one's general health status. The primary aim of this study was to report how the methodology of current evidence in hip fracture research can improve if studies included patients with cognitive impairment.

The Study to Prospectively Evaluate Reamed Intramedullary Nails in Tibial Shaft Fractures (SPRINT) randomised 1,226 patients treated by intramedullary nailing to reamed versus unreamed groups. We aimed to determine if there was a difference in the number of patients requiring more than one reoperation between the groups.

We hypothesised there would be differences in the number of patients with more than one reoperation in the reamed versus unreamed groups and in patients with open fractures versus closed fractures.

We identified patients requiring more than one reoperation during the 12 m follow-up. We considered those that were reamed versus unreamed, open versus closed, and those with a reoperation planned post 12 m follow-up. We also compared patient and fracture characteristics.

We identified a total of 44 patients requiring two or more reoperations. No difference between the reamed and unreamed groups was found in the risk of having more than one reoperation. Patients with two or more reoperations were older (p=0.03), had a higher frequency of open fractures (p<0.001), and had higher energy mechanisms of injury (p<0.001). The first reoperation was in response to infection for 25 patients. 12 patients had additional reoperations planned after the 12 m follow-up.

A relatively small number of tibial shaft fracture patients required more than one reoperation. Further study is required to assess consequences of needing multiple reoperations in this high risk group.

Introduction

Nonunion is a common and costly fracture outcome. Intricate reciprocity between angiogenesis and osteogenesis means vascular cell-based therapy offers a novel approach to stimulating bone regeneration.

Implant alignment in knee arthroplasty has been identified as critical factor for a successful outcome. Human error during the registration process for imageless computer navigation knee arthroplasty directly affects component alignment. This cadaveric study aims to define the error in the registration of the landmarks and the resulting error in component alignment.

Five fresh frozen cadaveric limbs including the hemipelvis were used for the study. Five surgeons performed the registration process via a medial parapatellar approach five times. In order to identify the gold standard point, the soft tissues were stripped and the registration was repeated by the senior author. Errors are presented as mm or degrees from the gold standard registration.

The error range in the registration of the femoral centre in the coronal plane was 6.5mm laterally to 5.0mm medially (mean: −0.1, SD: 2.7). This resulted in a mechanical axis error of 5.2 degrees valgus to 2.9 degrees varus (mean: 0.1, SD: 1.1). In the sagittal plane this error was between −1.8 degrees (extension) and 2.7 degrees (flexion). The error in the calculation of the tibial mechanical axis ranged from −1.0 (valgus) to 2.3 (varus) degrees in the coronal plane and −3.2 degrees of extension to 1.3 degrees of flexion. Finally the error in calculating the transepicondylar axis was −11.2 to 6.3 degrees of internal rotation (mean: −3.2, SD: 3.9).

The error in the registration process of the anatomical landmarks can result in significant malalignment of the components. The error range for the mechanical axis of the femur alone can exceed the 3 degree margin that has been previously been associated with implant longevity. The technique during the registration process is of paramount importance for image free computer navigation. Future research should be directed towards simplifying this process and minimizing the effect of human error.

Introduction

Hip resurfacing arthroplasty (HRA) has seen a recent revival with third generation Metal-on-Metal prostheses and is now widely in use. However, safety and effectiveness of hip resurfacing are still questioned. We systematically reviewed peer-reviewed literature on hip resurfacing arthroplasty to evaluate implant survival and functional outcomes of hybrid Metal-on-Metal hip resurfacing Arthroplasty.

Background

Hip resurfacing arthroplasty (HRA) has seen a recent revival with third generation Metal-on-Metal prostheses and is now widely in use. However, safety and effectiveness of hip resurfacing are still questioned. We systematically reviewed peer-reviewed literature on hip resurfacing arthroplasty to address these issues.

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

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.

Five hundred and twenty-seven consecutive primary total hip replacements were identified using either of the geometric variants of the acetabular component. Results at a mean of 7 years revealed a 95.6% survivorship with no significant difference between the two component designs with revision for aseptic loosening as the end point. Functional scores between the two groups of patients also demonstrated no statistically significant difference.

Radiologic assessment, however, showed a difference between the two designs. The hemispherical design which matches the reamer line-to-line had 80% complete osseointegration on final radiologic review while the second design with a peripheral rim expansion had only 57% complete osseointegration. This was statistically significant. The peripherally expanded components also had a greater number of screws inserted at the time of surgery, felt by us to be a reflection of initial surgeon dissatisfaction with component stability at the time of insertion of the component.

The difference in screw numbers was also statistically significant. This study demonstrates that a hemispherical design with line-to-line contact between the acetabular component surface and the acetabular bone is statistically superior in terms of bone ingrowth and probably statistically superior in terms of initial press-fit stability when compared to a peripherally expanded component.

Peripherally expanded components appear to offer no advantage over hemispherical components in terms of clinical outcome and are statistically inferior to hemispherical components in radiologic parameters at 7 years follow-up.

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.

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.

Ninety seven hip replacements in eighty seven patients were available for review at a minimum of five years. Two hips were revised (one for infection and one for periprosthetic fracture), leaving a total of ninety four hips available for final review. There were no differences in age, gender, body mass index, diagnosis, level of activity, and co-morbidities between the three groups. At a minimum of five years there were no statistical differences in the clinical outcomes using the WOMAC or SF12 scores. Three patients in the ceramic group reported squeaking. Radiological evaluation revealed mean annual wear rates in the ceramic group of 0.006mm/yr, standard polyethylene of 0.151mm/yr and highly cross linked polyethylene of 0.059mm/yr. ANOVA analysis revealed these differences in wear rates to be significant (p<0.0001).

In the mid term there are no differences in clinical outcome between ceramic on ceramic, cobalt chrome on ultra-high molecular weight polyethylene, and cobalt chrome on highly cross-linked polyethylene bearing surfaces in total hip arthroplasty. Ultra high molecular weight polyethylene has a significantly greater annual linear wear rate than highly cross-linked polyethylene.

Purpose

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

To review prospectively collected data on patients undergoing femoral revision arthroplasty for failed cemented or cementless primary stems.

Aim

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.

We designed this study to determine the clinical evidence to support use of the five degree tibial extra-medullary cutting block over the zero degree cutting block.

We identified three groups of patients from the databases and clinical notes at St Michaels Hospital, Toronto. Group one were primary total knees performed using the five degree cutting block, group two were primary total knees performed using the zero degree cutting block and the third group were computer navigated primary total knees. Patients in all three groups were age and sex matched. The senior author advocating use of the five degree block aimed to obtain a five degree posterior slope. The senior author who advocated the use of computer navigation, or the traditional zero degree cutting block, aimed to obtain a three degree posterior slope. All operations were performed by residents or clinical fellows, under the supervision of the senior authors. Patient radiographs were assessed to obtain the optimal direct lateral view obtained and they were saved on a database. Two independent blinded researchers assessed the posterior slope using Siemens Magicweb Software Version VA42C_0206. Two methods were used and the results averaged. The average posterior slope for the navigated total knee replacements was 0.1 degrees (−2 to 4). The average posterior slope for the five degree cutting block was 5.2 degrees (−2 to 16). The average posterior slope for the zero degree block was 3.79 degrees (−2 to 13). Computer navigated knee arthroplasty patients had significantly less variation in outlier measurements compared to the traditionally jigged arthroplasty patients. They were however, less accurate. The five degree cutting block tended to provide a more consistent posterior slope angle, but both the five degree and zero degree cutting blocks had variability in outliers. Computer Navigated Total Knee replacement provides a more consistent and reproducible tibial cut with less variability in alignment than extra-medullary jigs. The traditional five degree cutting block tended to provide a more reliable five degree posterior slope than the zero degree block, but was still subject to outliers.

The aim of this study was to determine the mid-term survival and functional outcomes of the Scorpio Total Stabilised Revision Knee prosthesis.

Sixty seven prostheses were implanted between November 2001 and April 2008. 42 females and 23 males. Average patient age was 67.9 (37-89). Outcomes were assessed with WOMAC (Western Ontario and McMaster Universities Osteoarthritis index), Knee Society Scores, Short Form-8 scores, patient satisfaction and radiological review. Average follow-up was over 3 years (8-93mths) with 95% follow-up.

One patient died post operatively and 4 patients from 18 months to 5 years post-operatively. Average body mass index was 32.9 (21.5- 55.1). 65% (42 patients) of patients operated on had a Body Mass Index of greater than 30. 48 patients were ASA 3 or greater.

Thirteen second stage revision arthroplasties were performed after treatment for infected arthroplasty surgery. Twenty six prostheses were revised for aseptic loosening. Eight prostheses were revised for stiffness and 9 for worn polyethylene inserts. Five prostheses were revised for symptomatic tibio-femoral instability/ dislocation and one for patello-femoral instability. Two revisions were performed for peri-prosthetic fractures and 2 for previously operated tibial plateau fractures.

Seven patients required tibial tubercle osteotomy and seven a rectus snip. Thirty one patients had greater than a 15mm polyethylene insert. The average KSS increased from 49 pre-operatively to 64 at 7.5 years. The average KS function score increased from 21 to 45. 68% (44) of patients had other significant joint involvement which affected daily function. 24% of patients were unsatisfied with the outcome. 89.5% of patients radiographs were assessed for loosening or subsidence. 51% of femoral components and 36% of tibial components had radiosclerotic lines. The surface area of each implant including the stem was measured on antero-posterior and lateral images. The degree of lucency was calculated as a percentage and in mm from the component.

Two prostheses (3%) were revised for deep infection, one (1.5%) for stiffness and one for aseptic loosening (1.5%). Complications included a popliteal artery injury, two superficial wound infections, and one patella tendon avulsion.

Survival rate for revision of prosthesis was 87% at 7.5 years and 90% excluding infection. Success of second stage revision arthroplasty after treatment of infection was 92%.

The purpose of this study was to evaluate 3 methods used to produce posterior tibial slope.

The purpose of this study was to evaluate total hip arthroplasty (THA) in the treatment of post-traumatic arthritis following acetabular fracture and to compare the long-term outcome of THA after previous open reduction and internal fixation (ORIF) or conservative treatment of the acetabular fracture.

Thirty-four patients (thirty-six hips) underwent total hip arthroplasty for arthritis resulting from acetabular fractures. There were twenty-six males (27 hips) and eight females (9 hips). The mean age at the time of hip arthroplasty was 49 years (range, 25-78 years). The mean follow-up was eight years and nine months (range, 4-17 years). The mean interval from fracture to arthroplasty was 7.5 years (range, 5 months-29 years). Two patients died of unrelated causes and two patients were lost to follow-up. Thirty patients (32 hips) were available for latest follow-up. Twenty-one hips had been previously treated by open reduction internal fixation and 11 hips had conservative treatment.

Sixteen patients achieved and maintained a good to excellent result over the course of the follow-up. There was no difference in improvement of mean Harris Hip Score between both groups (p>0.05). Ten out of 32 hips required revision; 9 acetabular components were revised because of aseptic loosening (3), osteolysis/excessive wear (4), instability (1) and infection (1) with a total revision rate of 28%. Eight patients needed acetabular revision alone, one femoral revision alone and one revision of both components. There was no significant difference in bone grafting, heterotopic bone formation, revision rate, operative time and blood loss between the two groups (p> 0.05).

Those patients initially treated conservatively had similar long term results compared to those treated primarily by open reduction internal fixation. At long term follow-up the main problem identified was osteolysis and acetabular wear.

We aimed to identify whether patients in lower socioeconomic groups had worse function prior to total knee arthroplasty and to establish whether these patients had worse post-operative outcome following total knee arthroplasty.

Data were obtained from the Kinemax outcome study, a prospective observational study of 974 patients undergoing primary total knee arthroplasty for osteoarthritis. The study was undertaken in thirteen centres, four in the United States, six in the United Kingdom, two in Australia and one in Canada. Pre-operative data were collected within six weeks of surgery and patients were followed for two years post-operatively. Pre-operative details of the patient's demographics, socioeconomic status (education and income), height, weight and co-morbid conditions were obtained. The WOMAC and SF-36 scores were also obtained. Multivariate regression was utilised to analyse the association between socioeconomic status and the patient's pre-operative scores and post-operative outcome. During the analysis, we were able to control for variables that have previously been shown to effect pre-operative scores and post-operative outcome.

Patients with a lower income had a significantly worse pre-operative WOMAC pain (p=0.021) and function score (p=0.039) than those with higher incomes. However, income did not have a significant impact on outcome except for WOMAC Pain at 12-months (p=0.014). At all the other post-operative assessment times, there was no correlation between income and WOMAC Pain and WOMAC Function. Level of education did not correlate with pre-operative scores or with outcome at any time during follow-up. This study demonstrates that across all four countries, patients with lower incomes appear to have a greater need for total knee arthroplasty. However, level of income and educational status did not appear to affect the final outcome following total knee arthroplasty. Patients with lower incomes appear able to compensate for their worse pre-operative score and obtain similar outcomes post-operatively.

Surgeons performing hip resurfacing ante-vert and translate the femoral component anterior to maximize head/neck offset and educe impingement. The anterior femoral neck is under tensile forces during gait similarly to the superior neck [6]. This study was esigned to determine the risk of femoral neck fracture after anterior or posterior notching of the femoral neck.

Method: Fortyseven 4th generation synthetic femora were implanted with Birmingham Hip Resurfacing pros-theses (Smith & Nephew Inc. emphis, USA). Implant preparation was performed using imageless computer navigation (VectorVision SR 1.0, BrainLAB, Grmany). The virtual prosthesis was initially planned for neutral version and translated anterior, or posterior, to create the 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 8 experimental groups:2mm and 5mm anterior notches, 2mm and 5mm posterior notches, neutral alignment with no notching (control), 5mm superior notch, 5mm anterior notch tested with the femur in 25° flexion and 5mm posterior notch tested with the femur in 25° extension We tested the femora flexed at 25° flex-ion to simulate loading as seen during stair ascent. [3] The posterior 5mm 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 Neutral (Control) 4303.09 ± 911.04N Anterior 2mm 3926.62 ± 894.17N p=0.985 Anterior 5mm 3374.64 ± 345.65N p=0.379 Posterior 2mm 4208.09 ± 1079.81N p=1.0 Posterior 5mm 3988.07 ± 728.59N p=0.995 Superior 5mm 2423.07 ± 424.16N p=0.003 Anterior 5mm in 25° flexion 3048.11 ±509.24N p=0.087 Posterior 5mm in 25° extension 3104.61±592.67N p=0.117 Both the anterior 5mm notch tested in single-leg stance and anterior notch in flexion displayed lower compressive loads to failure (3374.64N and 3048.11N). The mean load to failure value for the posterior 5mm notches in extension was 3104.62N compared to 4303.09N for the control group. Our data suggests that anterior and posterior 2mm notches are not statistically significantly weaker in axial compression. The anterior 5mm notches tend towards significance in axial compression (p=0.38) and bordered significance in flexion (p=0.087). The 5mm posterior notches were not significantly weakened in axial compression (p=0.995), but tended towards significance in extension (p=0.117). The 5mm superior notch group was significantly weaker with axial compression supporting previous data published (p=0.003). We are currently assessing offset and other variables that may reduce data spread.

Conclusion: We conclude that anterior and posterior 2mm notching of the femoral neck has no clinical implications, however 5mm anterior notches may lead to fracture. The fracture is more likely to occur with stair ascent rather than normal walking. Posterior 5mm notches are not likely to fracture with normal gait, but may fracture with higher impact activities that promote weight bearing in extension. Hip resurfacing is commonly performed on active patients and ultimately 5mm notching in the anterior or posterior cortices has clinically important implications.

Oxidized Zirconium (Oxinium, Smith & Nephew, Inc., Memphis, TN) is a relatively new material that features an oxidized ceramic surface chemically bonded to a tough metallic substrate. This material has demonstrated the reduced polyethylene wear characteristics of a ceramic, without the increased risk of implant fracture. The purpose of the current investigation was to assess clinical outcomes following primary total hip arthroplasty with Oxinium versus Cobalt Chrome femoral heads.

One hundred uncemented primary total hip arthroplasty procedures were prospectively performed in 100 patients. There were 52 males and 48 females with mean age at the time of surgery of 51 years (SD 11, range, 19–76). Using a process of sealed envelope randomization, patients were divided into 2 groups. Each group contained fifty patients. Those in group 1 received an Oxinium femoral head (OX), while those in group 2 a cobalt-chrome femoral head (CC).

The current study reports clinical outcome measures for both the OX and CC groups at a minimum follow-up of 2 years postoperatively. At the time of latest follow-up, stem survival for both groups was 98%. There was a significant improvement in all clinical outcome scores between preoperative and 2 year postoperative time periods for both bearing groups (p< 0.003). There were no significant differences between bearing groups for any of the clinical outcome scores at final follow-up (p> 0.159). Mean Harris Hip Scores at 2 years postoperatively were 92 and 92.5 for OX and CC, respectively (range; 65–100 OX, 60–100 CC). For SF-12, both the Physical Component Summary Scale (PCS) and the Mental Component Summary Scale (MCS) are reported. Mean PCS scores at final follow-up were 45.2 and 49.21 for OX and CC (range; 27.1–56.7 OX, 26.3–61.8 CC). Mean MCS scores were 53.8 and 52.57 for OX and CC (range; 39.2–65.5 OX, 34.3–64 CC). Mean final WOMAC scores are reported as 84.9 and 87 for OX and CC, respectively.

The current data suggest that total hip arthroplasty utilizing Oxinium femoral heads is safe and effective. Additional follow-up of the current cohort will be performed in order to fully assess mid-to long-term clinical outcomes.

Posterior slope of the tibial component is an important factor in overall alignment of Total Knee Arthroplasty. The purpose of this study was to compare the accuracy and reproducibility of tibial bone cuts utilizing traditional extramedullary 0 degree and angled 5 degree cutting blocks, and computer aided navigation, in primary total knee arthroplasty.

We identified 3 groups of patients. Group one were primary total knees performed using an extramedullary 0 degree cutting block for posterior slope, group 2 were performed using an extramedullary 5 degree cutting block and the third group were performed with computer navigation. Patients in all 3 groups were age and sex matched. All operations were performed by residents or clinical fellows, under the supervision of the senior authors. Lateral digital radiographs were reviewed and posterior slope was determined in a standardized fashion. Two independent blinded researchers assessed the posterior slope using Siemens Magicweb software version VA42C_0206.

The average difference from the ideal posterior slope in navigated knees was lower than with non-navigated knees, however this was not significant (p=0.086). The average difference from the ideal posterior slope in computer navigated knees was 1.77 degrees (95% CI=1.28 to 2.26) compared to 2.37 degrees (95% CI=1.56 to 3.17) with the 5 degree cutting block and 2.70 degrees (95% CI=1.73 to 3.66) with the 0 degree block. No absolute significant difference was highlighted between the 3 groups using ANOVA testing (p=0.22).

All three techniques used to obtain ideal tibial slope were accurate. Accuracy was not increased by the use of computer navigation; however navigation resulted in less variation in outcome. The two jig based methods produced similar outcomes and either technique can be used successfully.

This study was designed to determine the risk of femoral neck fracture after anterior or posterior notching of the femoral neck. The anterior femoral neck is under tensile forces during gait similarly to the superior neck [6].

Method: Fortyseven 4th generation synthetic femora were implanted with Birmingham Hip Resurfacing pros-theses (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. This method enabled comparison with previously published data. The synthetic femora were prepared in 8 experimental groups: 2mm and 5mm anterior notches, 2mm and 5mm posterior notches, neutral alignment with no notching (control), 5mm superior notch, 5mm anterior notch tested with the femur in 25° flexion and 5mm 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 5mm 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

Neutral (Control) 4303.09 ± 911.04N

The anterior 5mm notch tested in single-leg stance and anterior notch in flexion displayed lower compressive loads to failure (3374.64N and 3048.11N). The mean load to failure value for the posterior 5mm notches in extension was 3104.62N compared to 4303.09N for the control group.

Our data suggests that anterior and posterior 2mm notches are not significantly weaker in axial compression. The anterior 5mm notches was not significant in axial compression (p=0.38), but trended towards significance in flexion (p=0.087). A 5mm posterior notch was not significant. (p=0.995, p=0.117). The 5mm superior notch group was significantly weaker with axial compression supporting previous published data (p=0.003).

Conclusion: We conclude that anterior and posterior 2mm notching of the femoral neck has no clinical implications, however a 5mm anterior femoral neck notch may lead to fracture. The fracture is more likely to occur with stair ascent rather than normal walking given the reduction in strength noted after testing in flexion. Posterior 5mm notches are not likely to fracture. Hip resurfacing is commonly performed on active patients and 5mm notching of anterior cortex has clinically important implications.

Minimizing tip-apex distance has been shown to reduce clinical failure of sliding hip screws used to fix peritro-chanteric fractures. The purpose of this study was to determine if such a relationship exists for the position of the lag screw in the femoral head using a cephalomedullary device.

Methods: Thirty intact synthetic femur specimens (Model #3406, Pacific Research Laboratories, Vashon, WA) were potted into cement blocks distally for testing on an Instron 8874 (Instron, Canton, MA). A long cephalomedullary nail (Long Gamma 3 Nail, Stryker, Mahwah, NJ) was inserted into each of the femurs. An unstable four-part fracture was created, anatomically reduced, and repaired using one of 5 lag screw placements in the femoral head:

Superior (N=6),

Mechanical tests were repeated for axial, lateral and torsional stiffness. All specimens were radiographed in the anterioposterior and lateral planes and tip-apex (TAD) distance was calculated. A calcar referenced tip-apex distance (CalTAD) was also calculated.

ANOVA was used to compare means of the five treatment groups. Linear regression analysis was used to compare axial, lateral and torsional stiffness (dependant variables) to both TAD and CalTAD (independent variables).

Results: ANOVA testing proved that the mean axial (p< 0.01) and torsional stiffness (p< 0.01) between the 5 groups was significantly different, but lateral stiffness was not statistically different (p=0.494). Post hoc analysis showed that the inferior lag screw position provided significantly higher mean axial stiffness (568.14±66.9N/ mm) than superior (428.0±45.6N/mm; p< 0.01), anterior (443.2±45.4N/mm; p=0.02) and posterior (456.7±69.3N/ mm; p=0.04) lag screw positions. There was no significant difference in mean axial stiffness between inferior (568.14±66.9N/mm) and central (525.4±81.7N/mm) lag screw positions (p=0.77). Post hoc analysis revealed significantly less mean torsional stiffness for the superior lag screw position compared to other lag screw positions (p< 0.01 all 4 pairings). There were no significant correlations between TAD and axial (r=−0.33, p=0.08), lateral (r=−0.22, p=0.24) or torsional (r=0.08, p=0.69) stiffness. There were significant correlations between CalTAD and axial (r=−0.66, p< 0.01), lateral (r=−0.38, p=0.04) and torsional (r=−0.38, p=0.04) stiffness.

Discussion: Our results suggest that placement of the lag screw inferiorly in the femoral head when using a cephalomedullary nail to treat an unstable peritrochanteric fracture results in the stiffest construct in axial and torsional biomechanical testing. A simple radiographic measurement, CalTAD, provides an intraoperative method of determining optimal cephalomedullary nail lag screw position to achieve greatest construct stiffness.

The use of metal on polyethylene articulations was a key development in establishing total hip arthroplasty as a successful and reproducible treatment for end stage osteoarthritis. In order to ensure implant durability in relatively younger populations, there is a need for alternative, wear resistant bearing surfaces. Oxidized Zirconium (Oxinium, Smith & Nephew, Inc., Memphis, TN) is a relatively new material that features an oxidized ceramic surface chemically bonded to a tough metallic substrate. This material has demonstrated the reduced polyethylene wear characteristics of a ceramic, without the increased risk of implant fracture. The purpose of the current investigation was to assess early clinical outcomes following primary total hip arthroplasty with Oxinium versus Cobalt Chrome femoral heads.

One-hundred primary THA procedures were prospectively performed in 100 patients. There were 52 males and 48 females. Using a process of sealed envelope randomization, patients were divided into 2 groups. Group 1 consisted of fifty patients, each receiving primary THA implants with an Oxinium femoral head (OX). The mean age of each patient was 51 years (SD 10.8, Range 22–74) with 26 males and 24 females. Group 2 also consisted of 50 patients. Within this group again each patient received primary THA implants however with a cobalt-chrome femoral head (CC). Demographics were similar with mean age 51 years (SD 11.0, Range 19–76) and again 26 males and 24 females.

The current study reports clinical outcome measures for both the OX and CC groups at a minimum follow-up of 2 years postoperatively. At the time of latest follow-up, stem survival for both groups was 98%. There was a significant improvement in all clinical outcome scores between preoperative and 2 year postoperative time periods for both bearing groups (p< 0.003). There were no significant differences between bearing groups for any of the clinical outcome scores at final follow-up (p> 0.159). Mean Harris Hip Scores at 2 years postoperatively were 92 and 92.5 for OX and CC, respectively (range; 65–100 OX, 60–100 CC). For SF-12, both the Physical Component Summary Scale (PCS) and the Mental Component Summary Scale (MCS) are reported. Mean PCS scores at final follow-up were 45.2 and 49.21 for OX and CC (range; 27.1–56.7 OX, 26.3–61.8 CC). Mean MCS scores were 53.8 and 52.57 for OX and CC (range; 39.2–65.5 OX, 34.3–64 CC). Mean final WOMAC scores are reported as 84.9 and 87 for OX and CC, respectively.

The current data suggest that total hip arthroplasty utilizing Oxinium femoral heads is safe and effective. Additional follow-up of the current cohort will be performed in order to fully assess mid- to long-term clinical outcomes.

Background: Hip fracture trials have employed a wide range of patient-reported outcomes (PRO) suggesting a lack of consensus among clinicians on what are considered the most relevant outcomes. Variability in functional outcome reporting in hip fracture management creates challenges in the comparison of results across trials. The purpose of this study was to conduct a systematic review of the functional outcomes fielded in randomized controlled trials in post-operative hip fracture treatment for the aged. We hypothesized that over time there had been an increase in patient-reported outcomes along with aggregate scoring systems of hip function.

Methods: An electronic database search was conducted using key terms combining: ‘hip fracture’ with ‘RCT’ with ‘age 65 years and over’. s and titles were screened in duplicate and independently. All of the articles that met eligibility criteria were reviewed using the 21-point Detsky Quality Assessment Scale.

Results: In 2451 citations, 86 studies were included and also met accepted standards of inter-observer reliability (kappa, 0.92; 95% confidence interval, 0.87 to 0.98). The mean score (and standard error) for the quality of the randomized trials was: 75.8% ± 1.76% (95% confidence interval, 72.3%–79.3%) and 27 (32.6%) of the trials scored < 75%. Medical trials had a higher mean quality score than did surgical trials (83.7% compared with 72.7 %, p = 0.025). 59 trials (30 Surgical, 11 medical and 18 rehabilitation trials) scored > 75% in quality. Out of 86 trials, 8 (13.6%) used EQ-5D for utility and 6 (10.1%) used the SF-36 health status measures. At most, 12 trials used the same composite score: 12 (13.9%) ADL Katz Index, 9 (10.4%) trials used the HHS and 8 (9.3%) trials used Parker’s mobility score.

Conclusion: Although in the past decade more studies have made use of outcome instruments that capture both impairment and functional status in one aggregate score, there is a lack of standardized assessment.

Introduction: This study aimed to determine the accuracy of computer navigation in simulated fixation of femoral neck and supracondylar femoral fractures using different sizes of guidewires and drills from commercially available cannulated screw systems.

Methods: Simulated fracture fixation was performed with 2.5mm, 2.8mm and 3.2mm threaded guidewires and 3.2mm and 5mm drill bits using 20 4th generation synthetic femurs. The drill or guide wire was inserted in the synthetic femurs, using fluoroscopy based computer navigation (24 drills/guidewires in each group). Pre and postoperative fluoroscopy images were acquired with the C-arm and synthetic bone in the same orientations. Virtual and real wire/drill positions were compared, and errors calculated for each diameter of drill/guidewire (sum AP + Lateral error (mm)). Errors were compared using a general linear model with Tukey adjustment for multiple comparisons. Statistical significance at a two-tailed p-value < 0.05.

Results: The mean error for the 5.0mm drill (3.20mm) was significantly less than all the threaded wires (p< 0.05). The mean error for the 3.2mm drill (5.68mm) was significantly less than the 2.5mm guidewire (9.27mm) p< 0.05, and less than the 2.8mm (8.19mm) and 3.2mm (7.14mm) threaded wires.

Discussion: For cannulated screws, the 3.2mm drill was the most accurate size tested. The most accurate drill, 5mm, would allow solid screw insertion. However, its large size may preclude screw repositioning, and unlike a cannulated screw, would not maintain fracture position whilst the screw was being inserted.

Introduction: This study compared the accuracy of reduction of intra-medullary nailed femoral shaft fractures, comparing conventional and computer navigation techniques.

Methods: Twenty femoral shaft fractures were created in human cadavers, with segmental defects ranging from 9–53mm in length. All fractures were fixed with antegrade 9mm diameter femoral nails on a radiolucent operating table. Five fractures (control) were fixed with conventional techniques. Fifteen fractures (study) were fixed with computer navigation, using fluoroscopic images of the normal femur to correct for length and rotation. The surgeon was blinded to defect size. Two landmark protocols were used in the study group referencing the piriform fossa (Group A, n=10) or proximal shaft axis (Group B, n=5). Postoperative CT scans, blindly reported by a musculoskeletal radiologist, were used to compare femoral length and rotation with the normal leg.

Results were analysed using ANOVA with 95% Confidence Intervals.

Results: The control and study groups were not statistically different with respect to age of cadaver or size of femoral defect. Results: The mean leg length discrepancy in the study groups were significantly less (3.6mm (95% CI 1.072 – 6.128) and 4.2mm (95% CI 0.63–7.75), compared with 9.8mm (95% CI 6.225 – 13.37) in the control group (p< 0.023). The mean torsional deformities in the study groups were 8.7 degrees (95% CI 4.282 – 13.12) and 5.6 degrees (95% CI -0.65 – 11.85), compared with 9 degrees (95% CI 2.752 – 15.25) in the control group (p=0.650). Within the navigated study group, length discrepancy was similar in subgroups 1 (3.6mm) and 2 (4.2mm). Torsion appeared more accurate in group 2 (5.6 degrees) than group 1 (8.7 degrees), although this was not statistically significant.

Discussion: Computer navigation significantly improves the accuracy of femoral shaft fracture fixation with regard to length. With further modifications to improve reduction of rotational deformity, it may be a useful technique in the treatment of femoral fractures.

Aim of the study: To evaluate the use of a gelfoam sponge as a scaffold material in delivering osteoblast cells transfected with the VEGF gene for fracture repair.

Methods: In vitro: Osteoblasts were cultured from periosteum of rabbit bone and labeled with the visible CMTMR. Commercially available gelfoam with 12 pieces (each 3 × 3 × 3 mm3) was impregnated and cultured with the labelled cells (1×106) in a 12 wells plate for 1, 3 and 7 days. We embedded the gelfoam with labeled cells in an OCT compound enface, and the sections were then examined under a fluorescent microscope. In vivo: Osteoblasts were transfected with VEGF by use of SuperFect (Qiagen Inc) and cultured for 24 hours. The gelfoam pieces were impregnated with the transfected cells (5×106) saline solution for 30 minutes and placed into a segmental bone defect created in the rabbit tibia for 7 (n=3) and 14 (n=3) days. The specimens including the new bone were cut through each site of the segmental defect and embedded in paraffin. The sections were dewaxed and immunostained with mouse anti-human VEGF.

Results: In vitro: CMTMR-labeled cells survived and were detected within gelfoam at different time intervals (days 1, 3 and 7). In vivo: Immunostained VEGF proteins were visualized in the tissues surrounding the residual gel-foam at the fracture site at days 7 and 14 post surgery.

Conclusion: Our results indicate that the labeled/transfected cells are capable of growth in a gelfoam sponge both in vitro and in vivo.