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Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 27 - 27
1 Dec 2022
Suter T Old J McRae S Woodmass J Marsh J Dubberley J MacDonald PB
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Adequate visual clarity is paramount to performing arthroscopic shoulder surgery safely, efficiently, and effectively. The addition of epinephrine in irrigation fluid, and the intravenous or local administration of tranexamic acid (TXA) have independently been reported to decrease bleeding thereby improving the surgeon's visualization during arthroscopic shoulder procedures. No study has compared the effect of systemic administered TXA, epinephrine added in the irrigation fluid or the combination of both TXA and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. The purpose of this study is to determine if intravenous TXA is a safe alternative to epinephrine delivered by a pressure-controlled pump in improving arthroscopic shoulder visualization during arthroscopic procedures and whether using both TXA and epinephrine together has an additive effect in improving visualization.

The design of the study was a double-blinded, randomized controlled trial with four 1:1:1:1 parallel groups conducted at one center. Patients aged ≥18 years undergoing arthroscopic shoulder procedures including rotator cuff repair, arthroscopic biceps tenotomy/tenodesis, distal clavicle excision, subacromial decompression and labral repair by five fellowship-trained upper extremity surgeons were randomized into one of four arms: Pressure pump-controlled regular saline irrigation fluid (control), epinephrine (1ml of 1:1000) mixed in irrigation fluid (EPI), 1g intravenous TXA (TXA), and epinephrine and TXA (EPI/TXA). Visualization was rated on a 4-point Likert scale every 15 minutes with 0 indicating ‘poor’ quality and 3 indicating ‘excellent’ quality. The primary outcome measure was the unweighted mean of these ratings. Secondary outcomes included mean arterial blood pressure (MAP), surgery duration, surgery complexity, and adverse events within the first postoperative week.

One hundred and twenty-eight participants with a mean age (± SD) of 56 (± 11) years were randomized. Mean visualization quality for the control, TXA, EPI, and EPI/TXA groups were 2.1 (±0.40), 2.1 (±0.52), 2.6 (±0.37), 2.6 (±0.35), respectively. In a regression model with visual quality as the dependent variable, the presence/absence of EPI was the most significant predictor of visualization quality (R=0.525; p < 0 .001). TXA presence/absence had no effect, and there was no interaction between TXA and EPI. The addition of MAP and surgery duration strengthened the model (R=0.529; p < 0 .001). Increased MAP and surgery duration were both associated with decreased visualization quality. When surgery duration was controlled, surgery complexity was not a significant predictor of visualization quality. No adverse events were recorded in any of the groups.

Intravenous administration of TXA is not an effective alternative to epinephrine in the irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries although its application is safe. There is no additional improvement in visualization when TXA is used in combination with epinephrine beyond the effect of epinephrine alone.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 48 - 48
1 Dec 2022
Sogbein O Marsh J Somerville L Howard J Lanting B
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We recently performed a clinical trial comparing motor sparing blocks (MSB) to periarticular infiltration (PAI) following total knee arthroplasty (TKA). We found that MSBs provided longer analgesia (8.8 hours) than PAI with retention of quadriceps strength, and with similar function, satisfaction, and length of hospital stay. However, its potential increased cost could serve as a barrier to its adoption. Therefore, our aim was to compare the costs of MSBs to PAI following TKA.

We conducted a retrospective review of data from our previous RCT. There were 82 patients included in the RCT (n=41 MSB group, n=41 PAI group). We compared the mean total costs associated with each group until hospital discharge including intervention costs, healthcare professional service fees, intraoperative medications, length of stay, and postoperative opioid use.

Seventy patients were included (n=35 MSB group, n=35 PAI group). The mean total costs for the MSB group was significantly higher ($1959.46 ± 755.4) compared to the PAI group ($1616.25 ± 488.33), with a mean difference of $343.21 (95% CI = $73.28 to $664.11, p = 0.03). The total perioperative intervention costs for performing the MSB was also significantly higher however postoperative inpatient costs including length of stay and total opioid use did not differ significatnly.

Motor sparing blocks had significantly higher mean total and perioperative costs compared to PAI with no significant difference in postoperative inpatient costs. However, its quadricep sparing nature and previously demonstrated prolonged postoperative analgesia can be used to facilitate an outpatient TKA pathway thereby offsetting its increased costs.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 5 - 5
1 Dec 2022
McRae S Suter T Old J Zhang Y Woodmass J Marsh J Dubberley J MacDonald P
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Adequate visual clarity is paramount to performing arthroscopic shoulder surgery safely, efficiently, and effectively. The addition of epinephrine in irrigation fluid, and the intravenous or local administration of tranexamic acid (TXA) have independently been reported to decrease bleeding thereby improving the surgeon's visualization during arthroscopic shoulder procedures. No study has compared the effect of systemic administered TXA, epinephrine added in the irrigation fluid or the combination of both TXA and epinephrine on visual clarity during shoulder arthroscopy with a placebo group. The purpose of this study is to determine if intravenous TXA is a safe alternative to epinephrine delivered by a pressure-controlled pump in improving arthroscopic shoulder visualization during arthroscopic procedures and whether using both TXA and epinephrine together has an additive effect in improving visualization.

The design of the study was a double-blinded, randomized controlled trial with four 1:1:1:1 parallel groups conducted at one center. Patients aged ≥18 years undergoing arthroscopic shoulder procedures including rotator cuff repair, arthroscopic biceps tenotomy/tenodesis, distal clavicle excision, subacromial decompression and labral repair by five fellowship-trained upper extremity surgeons were randomized into one of four arms: Pressure pump-controlled regular saline irrigation fluid (control), epinephrine (1ml of 1:1000) mixed in irrigation fluid (EPI), 1g intravenous TXA (TXA), and epinephrine and TXA (EPI/TXA). Visualization was rated on a 4-point Likert scale every 15 minutes with 0 indicating ‘poor’ quality and 3 indicating ‘excellent’ quality. The primary outcome measure was the unweighted mean of these ratings. Secondary outcomes included mean arterial blood pressure (MAP), surgery duration, surgery complexity, and adverse events within the first postoperative week.

One hundred and twenty-eight participants with a mean age (± SD) of 56 (± 11) years were randomized. Mean visualization quality for the control, TXA, EPI, and EPI/TXA groups were 2.1 (±0.40), 2.1 (±0.52), 2.6 (±0.37), 2.6 (±0.35), respectively. In a regression model with visual quality as the dependent variable, the presence/absence of EPI was the most significant predictor of visualization quality (R=0.525; p < 0 .001). TXA presence/absence had no effect, and there was no interaction between TXA and EPI. The addition of MAP and surgery duration strengthened the model (R=0.529; p < 0 .001). Increased MAP and surgery duration were both associated with decreased visualization quality. When surgery duration was controlled, surgery complexity was not a significant predictor of visualization quality. No adverse events were recorded in any of the groups.

Intravenous administration of TXA is not an effective alternative to epinephrine in the irrigation fluid to improve visualization during routine arthroscopic shoulder surgeries although its application is safe. There is no additional improvement in visualization when TXA is used in combination with epinephrine beyond the effect of epinephrine alone.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 32 - 32
1 Dec 2022
Kamikovski I Woodmass J McRae S Lapner P Jong B Marsh J Old J Dubberley J Stranges G MacDonald PB
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Previously, we conducted a multi-center, double-blinded randomized controlled trial comparing arthroscopic Bankart repair with and without remplissage. The end point for the randomized controlled trial was two years post-operative, providing support for the benefits of remplissage in the short term in reducing recurrent instability. The aim of this study was to compare the medium term (3 to 9 years) outcomes of patients previously randomized to have undergone isolated Bankart repair (NO REMP) or Bankart repair with remplissage (REMP) for the management of recurrent anterior glenohumeral instability. The rate of recurrent instability and instances of re-operation were examined.

The original study was a double-blinded, randomized clinical trial with two 1:1 parallel groups with recruitment undertaken between 2011 and 2017. For this medium-term study, participants were reached for a telephone follow-up in 2020 and asked a series of standardized questions regarding ensuing instances of subluxation, dislocation or reoperation that had occurred on their shoulder for which they were randomized. Descriptive statistics were generated for all variables. “Failure” was defined as occurrence of a dislocation. “Recurrent instability” was defined as the participant reporting a dislocation or two or more occurences of subluxation greater than one year post-operative. All analyses were undertaken based on intention-to-treat whereby their data was analyzed based on the group to which they were originally allocated.

One-hundred and eight participants were randomized of which 50 in the NO REMP group and 52 in the REMP group were included in the analyses in the original study. The mean number of months from surgery to final follow-up was 49.3 for the NO REMP group and 53.8 for the REMP group. The rates of re-dislocation or failure were 8% (4/52) in the REMP group at an average of 23.8 months post-operative versus 22% (11/50) in the NO REMP at an average of 16.5 months post-operative. The rates of recurrent instability were 10% (5/52) in the REMP group at an average of 24 months post-operative versus 30% (15/50) in the NO REMP group at an average of 19.5 months post-operative. Survival curves were significantly different favouring REMP in both scenarios.

Arthroscopic Bankart repair combined with remplissage is an effective procedure in the treatment of patients with an engaging Hill-Sachs lesion and minimal glenoid bone loss (<15%). Patients can expect favourable rates of recurrent instability when compared with isolated Bankart repair at medium term follw-up.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 26 - 26
1 Dec 2022
Lapner P Pollock J Hodgdon T Zhang T McIlquham K Coupal S Bouliane M McRae S Dubberley J Berdusco R Stranges G Marsh J Old J MacDonald PB
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Our primary objective was to compare healing rates in patients undergoing arthroscopic rotator cuff repair for degenerative tears, with and without bone channeling. Our secondary objectives were to compare disease-specific quality of life and patient reported outcomes as measured by the Western Ontario Rotator Cuff Index (WORC), American Shoulder and Elbow Surgeons (ASES) score and Constant score between groups.

Patients undergoing arthroscopic rotator cuff repair at three sites were randomized to receive either bone channeling augmentation or standard repair. Healing rates were determined by ultrasound at 6 and 24 months post operatively. WORC, ASES, and Constant scores were compared between groups at baseline and at 3, 6, 12 and 24 months post operatively.

One hundred sixty-eight patients were recruited and randomized between 2013 to 2018. Statistically significant improvements occurred in both groups from pre-operative to all time points in all clinical outcome scores (p < 0 .0001). Intention to treat analysis revealed no statistical differences in healing rates between the two interventions at 24 months post-operative. No differences were observed in WORC, ASES or Constant scores at any time-point.

This trial did not demonstrate superiority of intra-operative bone channeling in rotator cuff repair surgery at 24 months post-operative. Healing rates and patient-reported function and quality of life measures were similar between groups.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 33 - 33
1 Mar 2021
Woodmass J McRae S Malik S Dubberley J Marsh J Old J Stranges G Leiter J MacDonald P
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When compared to magnetic resonance imaging (MRI), ultrasound (US) performed by experienced users is an inexpensive tool that has good sensitivity and specificity for diagnosing rotator cuff (RC) tears. However, many practitioners are now utilizing in-office US with little to no formal training as an adjunct to clinical evaluation in the management of RC pathology. The purpose of our study was to determine if US without formal training is effective in managing patients with a suspected RC tear.

This was a single centre prospective observational study. Five fellowship-trained surgeons each examined 50 participants referred for a suspected RC tear (n= 250). Patients were screened prior to the consultation and were included if ≥ 40 years old, had an MRI of their affected shoulder, had failed conservative treatment of at least 6 months, and had ongoing pain and disability. Patients were excluded if they had glenohumeral instability, evidence of major joint trauma, or osteonecrosis. After routine clinical exam, surgeons recorded their treatment plan (“No Surgery”, “Uncertain”, or “Surgery”). Surgeons then performed an in-office diagnostic US followed by an MRI and documented their treatment plan after each imaging study. Interrater reliability was analyzed using a kappa statistic to compare clinical to ultrasound findings and ultrasound findings to MRI, normal and abnormal categorization of biceps, supraspinatus, and subscapularis.

Following clinical assessment, the treatment plan was recorded as “No Surgery” in 90 (36%), “Uncertain” in 96 (39%) of cases, “Surgery” in 61 (25%) cases, and incomplete in 3 (2%). In-office US allowed resolution of 68 (71%) of uncertain cases with 227 (88%) of patients having a definitive treatment plan. No patients in the “No Surgery” group had a change in treatment plan. After MRI, 16 (6%) patients in the “No Surgery” crossed-over to the “Surgery” group after identification of full-thickness tears, larger than expected tears or alternate pathology (e.g., labral tear).

The combination of clinical examination and in-office US may be an effective method in the initial management of patients with suspected rotator cuff pathology. Using this method, a definitive diagnosis and treatment plan was established in 88% of patients with the remaining 12% requiring an MRI. A small percentage (6%) of patients with larger than expected full-thickness rotator cuff tears and/or alternate glenohumeral pathology (e.g., labral tear) would be missed at initial evaluation.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 21 - 21
1 Aug 2020
Somerville L Zomar B Vasarhelyi E Lanting B Howard J Marsh J
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Total knee arthroplasty is a successful procedure that reduces knee pain and improves function in most patients with knee osteoarthritis. Patient dissatisfaction however remains high, and along with implant longevity, may be affected by component positioning. Surgery in obese patients is more technically challenging with difficulty identifying appropriate landmarks for alignment and more difficult exposure of the joint. Patient specific instrumentation (PSI) has been introduced with the goal to increase accuracy of component positioning by custom fitting cutting guides to the patient using advanced imaging. A strong criticism of this new technology however, is the cost associated. The purpose of this study was to determine, using a prospective, randomized-controlled trial, the cost-effectiveness of PSI compared to standard instrumentation for total knee arthroplasty in an obese patient population.

Patients with a body mass index greater than 30 with osteoarthritis and undergoing a primary total knee arthroplasty were included in this study. We randomized patients to have their procedure with either standard instrumentation (SOC) or PSI. At 12-weeks post-surgery patients completed a self-reported cost questionnaire and the Western Ontario and McMaster Osteoarthritis Index (WOMAC). We performed a cost-effectiveness analyses from a public health payer and societal perspective. As we do not know the true cost of the PSI instrumentation, we estimated a value of $100 for our base case analysis and used one-way sensitivity analyses to determine the effect of different values (ranging from $0 to $500) would have on our conclusions.

A total of 173 patients were enrolled in the study with 86 patients randomized to the PSI group and 87 to the SOC group. We found the PSI group to be both less effective and more costly than SOC when using a public payer perspective, regardless of the cost of the PSI. From a societal perspective, PSI was both less costly, but also less effective, regardless of the cost of the PSI. The mean difference in effect between the two groups was −1.61 (95% CI −3.48, 026, p=0.091). The incremental cost-effectiveness ratio was $485.71 per point increase in the WOMAC, or $7285.58 per clinically meaningful difference (15 points) in the WOMAC.

Overall, our results suggest that PSI is not cost-effective compared to standard of care from a public payer perspective. From a societal perspective, there is some question as to whether the decreased effect found with the PSI group is worth the reduced cost. The main driver of the cost difference appears to be time off of volunteer work, which will need to be investigated further. In future, we will continue to follow these patients out to one year to collect cost and effectiveness data to investigate whether these results remain past 12 weeks post-surgery.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_11 | Pages 16 - 16
1 Aug 2018
McCalden R Ponnusamy K Marsh J Somerville L MacDonald S Naudie D Lanting B Howard J Vasarhelyi E
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The purpose of this study is to compare 90-day costs and outcomes for primary total hip arthroplasty (THA) patients between a non-obese (BMI 18.5–24.9) versus overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–44.9), and super-obese (45+) cohorts.

We conducted a retrospective review of a prospective institutional database of primary THA patients from 2006–2013, including patients with a minimum of three-year follow-up. Thirty-three super-obese patients were identified, and the other five cohorts were randomly selected in a 2:1 ratio (total n = 363). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after three years (revisions and change scores for SF12, HHS, and WOMAC) were collected. Costs were determined using unit costs from our institutional administrative data for all in-hospital resource utilization. Comparisons between the non-obese and other groups were made with Kruskal-Wallis tests for non-normal data and chi-square and Fisher's exact test for categorical data.

The 90-day costs in the morbidly-obese ($13,134 ± 7,250 mean ± standard deviation, p <0.01) and super-obese ($15,604 ± 6,783, p <0.01) cohorts were statistically significantly greater than the non-obese cohorts ($10,315 ± 1,848). Only the super-obese cohort had statistically greater 90-day reoperation and readmission rates than the non-obese cohort (18.2% vs 0%, p <0.01 and 21.2% vs 4.5%, p=0.02, respectively). In addition, reoperations and septic revisions after 3 years were greater in the super-obese cohort compared to the non-obese cohort 21.2% vs 3.0% (p = 0.01), and 18.2% vs 1.5% (p= 0.01), respectively. There were no other statistical differences between the other cohorts with the non-obese cohort at 90-days or after 3 years. Improvements in SF12, HHS, and WOMAC were comparable in all cohorts.

The 90-day costs of a primary total hip arthroplasty for morbidly-obese (BMI 40–44.9) and super-obese (BMI>45) are significantly greater than for non-obese patients, yet these patients have comparable improvements in outcome scores. Health care policies, when based purely on the economic impact of health care delivery, may place morbidly-obese and super-obese patients at risk of losing arthroplasty care, thereby denying them access to the comparable quality of life improvements.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_6 | Pages 67 - 67
1 Mar 2017
Vasarhelyi E Weeks C Graves S Kelly L Marsh J
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Background

The management of the patella during primary total knee arthroplasty (TKA) is controversial. Despite the majority of patients reporting excellent outcomes following TKA, a common complaint is anterior knee pain. Resurfacing of the patella at the time of initial surgery has been proposed as a means of preventing anterior knee pain, however current evidence, including four recent meta-analyses, has failed to show clear superiority of patellar resurfacing. Therefore, the purpose of this study was to estimate the cost-effectiveness of patellar resurfacing compared to non-resurfacing in TKA.

Methods

We conducted a cost-effectiveness analysis using a decision analytic model to represent a hypothetical patient cohort undergoing primary TKA. Each patient will receive a TKA either with the Patella Resurfaced or Not Resurfaced. Following surgery, patients can transition to one of three chronic health states: 1) Well Post-operative, 2) Patellofemoral Pain (PFP), or 3) Serious Adverse Event (AE), which we have defined as any event requiring Revision TKA, including: loosening/lysis, infection, instability, or fracture (Figure 1). We obtained revision rates following TKA for both resurfaced and unresurfaced cohorts using data from the 2014 Australian Registry. This data was chosen due to similarities between Australian and North American practice patterns and patient demographics, as well as the availability of longer term follow up data, up to 14 years postoperative. Our effectiveness outcome for the model was the quality-adjusted life year (QALY). We used utility scores obtained from the literature to calculate QALYs for each health state. Direct procedure costs were obtained from our institution's case costing department, and the billing fees for each procedure. We estimated cost-effectiveness from a Canadian publicly funded health care system perspective. All costs and quality of life outcomes were discounted at a rate of 5%. All costs are presented in 2015 Canadian dollars.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_3 | Pages 5 - 5
1 Feb 2017
Akindolire J Marsh J Howard J Lanting B Somerville L Vasarhelyi E
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Background

Total hip arthroplasty (THA) has become one of the most commonly performed elective procedures. Today, there are nearly 50 000 annual hospitalizations for hip replacement surgery in Canada. This number is projected to increase significantly with the aging population. Periprosthetic joint infection (PJI) is the 3rd leading cause of failure following THA and is reported to occur at an incidence of 1–3%. A two-stage revision THA is the current gold standard treatment and this has a tremendous economic impact on the healthcare system. The purpose of this study is to create an accurate cost estimate of two-stage revision THA and, in turn, evaluate the economic burden of PJI as it compares to primary THA in a Canadian healthcare context.

Methods

We conducted a retrospective review of primary THA cases and two-stage revision THA for PJI at our institution. Patients were matched for age and BMI. We recorded all costs associated with each procedure, including: OR time, equipment, length of hospital stay, readmission rates, and any other inpatient resource use. Unit costs were obtained using administrative data from the case costing department at London Health Sciences Centre. Billing fees associated with the procedure were obtained from the Ontario Schedule of Benefits. Descriptive statistics were used to summarize the demographic characteristics of patients, hospital costs and resource use data. Patients with PJI were compared to the matched cohort of primary THA using the t-test (for continuous variables), and the chi-square test (for categorical variables).


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_20 | Pages 63 - 63
1 Nov 2016
Akindolire J Marsh J Howard J Lanting B Somerville L Vasarhelyi E
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Total hip arthroplasty (THA) has become one of the most commonly performed elective procedures. Today, there are nearly 50 000 annual hospitalisations for hip replacement surgery in Canada. This number is projected to increase significantly with the aging population. Periprosthetic joint infection (PJI) is the 3rd leading cause of failure following THA and is reported to occur at an incidence of 1–3%. A two-stage re-vision THA is the current gold standard treatment and this has a tremendous economic impact on the healthcare system. The purpose of this study is to create an accurate cost estimate of two-stage revision THA and, in turn, evaluate the economic burden of PJI as it compares to primary THA in a Canadian healthcare context.

We conducted a retrospective review of primary THA cases and two-stage revision THA for PJI at our institution. Patients were matched for age and BMI. We recorded all costs associated with each procedure, including: OR time, equipment, length of hospital stay, readmission rates, and any other inpatient resource use. Unit costs were obtained using administrative data from the case costing department at London Health Sciences Centre. Billing fees associated with the procedure were obtained from the Ontario Schedule of Benefits. Descriptive statistics were used to summarise the demographic characteristics of patients, hospital costs and resource use data. Patients with PJI were compared to the matched cohort of primary THA using the t-test (for continuous variables), and the chi-square test (for categorical variables).

Twenty consecutive cases of revision THA were matched to 20 patients who underwent uncomplicated primary THA between 2006 and 2014. Periprosthetic infection was associated with a significant increase in hospital stay (26.5 vs. 2.0; p<0.001), clinic visits (9.5 vs. 3.8; p<0.001), readmission rates (12 vs. 1; p<0.001) and overall cost ($39 953 vs. $7 460; p<0.001) in comparison to the primary arthroplasty cohort.

Two-stage revision for infected THA is a significant economic burden to the healthcare system. Our data suggests a 5-fold increase in healthcare cost when compared to primary THA. This may be an important consideration when distributing resources among Canadian tertiary care centres.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 104 - 104
1 May 2016
Petis S Howard J Lanting B Marsh J Vasarhelyi E
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Introduction

Total hip arthroplasty (THA) is a commonly performed surgical procedure for the treatment of hip arthritis. Approximately 50,000 THAs are performed annually in Canada. The costs incurred to the healthcare system are tremendous, amounting to anywhere between 4.3 and 7.3 billion dollars each year. Despite the substantial financial burden of THA to the Canadian healthcare system, few studies have provided accurate cost estimations of this procedure.

Purpose

To determine the impact of surgical approach on costs of THA from a hospital perspective, and provide an updated cost estimation of THA within a publically funded healthcare system.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_II | Pages 82 - 82
1 Feb 2012
Dunbar M Griffin D Copas J Marsh J Lozada-Can C Kwong H Upadhyay P
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Thromboprophylaxis remains a controversial issue and many disagree about the optimum method or even if it is required at all.

We present a new method of performing meta-analysis incorporating studies with both experimental and observational study designs. We have developed a model that compares study cohorts of several different methods of thromboprophylaxis with a simulated matched control group whose variance helps to adjust for bias. This allows meaningful comparisons between studies and treatments that have not been directly compared.

We performed a systematic review of the literature from 1981 to October 2004. Studies where more than one method of prophylaxis was used were excluded from analysis. For each individual method of prophylaxis, data was extracted, combined and converted to give estimates of the rates of symptomatic, proximal DVT, fatal PE and major bleeding events. We identified 1242 studies of which 203 met the inclusion criteria for further analysis. This represented the results of over fifty thousand studied patients. We expressed the results for the different prophylactic methods as odds ratios compared to no prophylaxis.

All methods showed a beneficial effect in reducing VTEs apart from stockings and aspirin which showed an increase in the number of PE events. These results are particularly interesting when viewed from the standpoint of an individual NHS hospital trust that performs around 500 hip and knee replacements per year. Over a 5 year period, the more effective methods of prophylaxis prevented between 15 and 40 symptomatic DVTs and up to 3 fatal PEs compared to no treatment. However, they cause between 8 and 40 more major bleeding events. We do not know the proportion of these major bleeding events that are fatal.