David Wasserstein

The efficacy of platelet-rich plasma in the treatment of symptomatic knee osteoarthritis: a systematic review with quantitative synthesis.

PURPOSE The purpose of this systematic review was to synthesize the available Level I and Level II literature on platelet-rich plasma (PRP) as a therapeutic intervention in the management of symptomatic knee osteoarthritis (OA). METHODS A systematic review of Medline, Embase, Cochrane Central Register of Controlled Trials, PubMed, and www.clinicaltrials.gov was performed to identify all randomized controlled trials and prospective cohort studies that evaluated the clinical efficacy of PRP versus a control injection for knee OA. A random-effects model was used to evaluate the therapeutic effect of PRP at 24 weeks by use of validated outcome measures (Western Ontario and McMaster Universities Arthritis Index, visual analog scale for pain, International Knee Documentation Committee Subjective Knee Evaluation Form, and overall patient satisfaction). RESULTS Six Level I and II studies satisfied our inclusion criteria (4 randomized controlled trials and 2 prospective nonrandomized studies). A total of 577 patients were included, with 264 patients (45.8%) in the treatment group (PRP) and 313 patients (54.2%) in the control group (hyaluronic acid [HA] or normal saline solution [NS]). The mean age of patients receiving PRP was 56.1 years (51.5% male patients) compared with 57.1 years (49.5% male patients) for the group receiving HA or NS. Pooled results using the Western Ontario and McMaster Universities Arthritis Index scale (4 studies) showed that PRP was significantly better than HA or NS injections (mean difference, -18.0 [95% confidence interval, -28.8 to -8.3]; P < .001). Similarly, the International Knee Documentation Committee scores (3 studies) favored PRP as a treatment modality (mean difference, 7.9 [95% confidence interval, 3.7 to 12.1]; P < .001). There was no difference in the pooled results for visual analog scale score or overall patient satisfaction. Adverse events occurred more frequently in patients treated with PRP than in those treated with HA/placebo (8.4% v 3.8%, P = .002). CONCLUSIONS As compared with HA or NS injection, multiple sequential intra-articular PRP injections may have beneficial effects in the treatment of adult patients with mild to moderate knee OA at approximately 6 months. There appears to be an increased incidence of nonspecific adverse events among patients treated with PRP. LEVEL OF EVIDENCE Level II, systematic review of Level I and II studies.

How to set the bar in competency-based medical education: standard setting after an Objective Structured Clinical Examination (OSCE)

BackgroundThe goal of the Objective Structured Clinical Examination (OSCE) in Competency-based Medical Education (CBME) is to establish a minimal level of competence. The purpose of this study was to 1) to determine the credibility and acceptability of the modified Angoff method of standard setting in the setting of CBME, using the Borderline Group (BG) method and the Borderline Regression (BLR) method as a reference standard; 2) to determine if it is feasible to set different standards for junior and senior residents, and 3) to determine the desired characteristics of the judges applying the modified Angoff method.MethodsThe results of a previous OSCE study (21 junior residents, 18 senior residents, and six fellows) were used. Three groups of judges performed the modified Angoff method for both junior and senior residents: 1) sports medicine surgeons, 2) non-sports medicine orthopedic surgeons, and 3) sports fellows. Judges defined a borderline resident as a resident performing at a level between competent and a novice at each station. For each checklist item, the judges answered yes or no for “will the borderline/advanced beginner examinee respond correctly to this item?” The pass mark was calculated by averaging the scores. This pass mark was compared to that created using both the BG and the BLR methods.ResultsA paired t-test showed that all examiner groups expected senior residents to get significantly higher percentage of checklist items correct compared to junior residents (all stations p < 0.001). There were no significant differences due to judge type. For senior residents, there were no significant differences between the cut scores determined by the modified Angoff method and the BG/BLR method. For junior residents, the cut scores determined by the modified Angoff method were lower than the cut scores determined by the BG/BLR Method (all p < 0.01).ConclusionThe results of this study show that the modified Angoff method is an acceptable method of setting different pass marks for senior and junior residents. The use of this method enables both senior and junior residents to sit the same OSCE, preferable in the regular assessment environment of CBME.

Epidemiology of Primary Anterior Shoulder Dislocation Requiring Closed Reduction in Ontario, Canada

Background: There is a lack of high-quality population-based literature describing the epidemiology of primary anterior shoulder dislocation. Purpose: To (1) calculate the incidence density rate (IDR) of primary anterior shoulder dislocation requiring closed reduction (CR; “index event”) in the general population and demographic subgroups, and (2) determine the rate of and risk factors for repeat shoulder CR. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: All patients who underwent shoulder CR by a physician in Ontario between April 2002 and September 2010 were identified with administrative databases. Exclusion criteria included age <16 and >70 years, posterior dislocation, and prior shoulder dislocation or surgery. Index event IDR was calculated for all populations/subgroups, and IDR comparisons were made. Repeat shoulder CR was sought until September 2012. Risk factors for repeat shoulder CR were identified with a Prentice, Williams, and Peterson proportional hazards model. Results: There were 20,719 persons (median age, 35 years; 74.3% male) who underwent a shoulder CR after a primary anterior shoulder dislocation (23.1/100,000 person-years). The IDR was highest among young males (98.3/100,000 person-years). A total of 3940 (19%) patients underwent repeat shoulder CR after a median of 0.9 years, of which 41.7% were ≤20 years of age. Less than two-thirds of all first repeat shoulder CR events occurred within 2 years; in fact, 95% occurred within 5 years. The risk of repeat shoulder CR was lowest if the primary reduction had been performed by an orthopaedic surgeon (hazard ratio [HR], 0.76; 95% CI: 0.64, 0.90; P = .002) or was associated with a humeral tuberosity fracture (HR, 0.71; CI, 0.53, 0.95; P = .02). Older age (HR, 0.97; CI, 0.97, 0.98; P < .0001) and higher medical comorbidity score (HR, 0.92; CI, 0.87, 0.98; P = .009) were also protective. Risk was highest among males (HR, 1.26; CI, 1.16, 1.36; P < .0001) and patients from low-income neighborhoods (HR, 1.23; CI, 1.13, 1.34; P < .0001). Conclusion: Young male patients have the highest incidence of primary anterior shoulder dislocation requiring CR and the greatest risk of repeat shoulder CR. Patient, provider, and injury factors all influence repeat shoulder CR risk. A comprehensive understanding of the epidemiology of primary anterior shoulder dislocation will aid management decisions and injury prevention initiatives.

Risk Factors for Recurrent Anterior Cruciate Ligament Reconstruction

Background: Anterior cruciate ligament reconstruction (ACLR) is routinely performed for symptomatic instability. Although it is a common procedure, there remain differences in surgical technique. Hospital administrative records in a public health care system were used to investigate the effect of patient, provider, and surgical factors on the risk of revision ACLR. Purpose: To define the rate and risk factors for ACL reoperation in Ontario, Canada, including both ipsilateral revision and contralateral primary procedures. Study Design: Cohort study; Level of evidence, 3. Methods: All primary elective ACLR procedures performed in Ontario (July 2003 to March 2008) in patients aged 15 to 60 years were identified via physician billing and hospital databases. Revision and contralateral ACLR were sought until January 2012. Patient factors (age, sex, comorbidity, income quintile, length of index hospital admission), provider factors (surgeon volume, academic hospital status), and surgical factors (allograft vs autograft; fixation type [screw, button, staple]; concomitant operative procedures) were used as covariates in a Cox proportional hazards survivorship model to generate hazard ratios (HRs) with confidence intervals (CIs) (α = .05). Kaplan-Meier survivorship curves with ACL revision as the end point were generated. Results: A total of 12,967 ACLR procedures with a mean follow-up of 5.2 years were eligible for study using preset criteria. The revision rate was 2.6% (mean ± SD, 2.91 ± 1.71 years to revision). The rate of primary contralateral ACLR was 4.6% (mean, 2.95 ± 1.81 years). In the Cox model, younger age (15-19 years) (HR, 2.1; 95% CI, 1.5-2.9; P < .001), ACLR performed at an academic hospital (HR, 1.6; 95% CI, 1.2-2.1; P < .001), and the use of allograft (HR, 1.7; 95% CI, 1.1-2.6; P = .02) significantly increased the risk of revision ACLR. Only younger age (HR, 2.1; 95% CI, 1.6-2.7; P < .001) was associated with an increased risk of contralateral ACLR. Conclusion: Contralateral ACLR was more frequent than revision ACLR in this population, while both surgical procedures were most common in patients younger than 20 years. Academic hospital status, but not surgeon volume, as well as the use of allograft also increased the risk for revision ACLR.

Risk of total knee arthroplasty after operatively treated tibial plateau fracture: a matched-population-based cohort study.

BACKGROUND The aims of operative treatment of displaced tibial plateau fractures are to stabilize the injured knee to restore optimal function and to minimize the risk of posttraumatic arthritis and the eventual need for total knee arthroplasty. The purpose of our study was to define the rate of subsequent total knee arthroplasty after tibial plateau fractures in a large cohort and to compare that rate with the rate in the general population. METHODS All patients sixteen years of age or older who had undergone surgical treatment of a tibial plateau fracture from 1996 to 2009 in the province of Ontario, Canada, were identified from administrative health databases with use of surgeon fee codes. Each member of the tibial plateau fracture cohort was matched to four individuals from the general population according to age, sex, income, and urban/rural residence. The rates of total knee arthroplasty at two, five, and ten years were compared by using time-to-event analysis. A separate Cox proportional hazards model was used to explore the influence of patient, provider, and surgical factors on the time to total knee arthroplasty. RESULTS We identified 8426 patients (48.5% female; median age, 48.9 years) who had undergone fixation of a tibial plateau fracture and matched them to 33,698 controls. The two, five, and ten-year rates of total knee arthroplasty in the plateau fracture and control cohorts were 0.32% versus 0.29%, 5.3% versus 0.82%, and 7.3% versus 1.8%, respectively (p < 0.0001). After adjustment for comorbidity, plateau fracture surgery was found to significantly increase the likelihood of total knee arthroplasty (hazard ratio [HR], 5.29 [95% confidence interval, 4.58, 6.11]; p < 0.0001). Higher rates of total knee arthroplasty were also associated with increasing age (HR, 1.03 [1.03, 1.04] per year over the age of forty-eight; p < 0.0001), bicondylar fracture (HR, 1.53 [1.26, 1.84]; p < 0.0001), and greater comorbidity (HR, 2.17 [1.70, 2.77]; p < 0.001). CONCLUSIONS Ten years after tibial plateau fracture surgery, 7.3% of the patients had had a total knee arthroplasty. This corresponds to a 5.3 times increase in likelihood compared with a matched group from the general population. Older patients and those with more severe fractures are also more likely to need total knee arthroplasty after repair of a tibial plateau fracture.

Relation between surgeon volume and risk of complications after total hip arthroplasty: propensity score matched cohort study

Objectives To identify a cut point in annual surgeon volume associated with increased risk of complications after primary elective total hip arthroplasty and to quantify any risk identified. Design Propensity score matched cohort study. Setting Ontario, Canada Participants 37 881 people who received their first primary total hip arthroplasty during 2002-09 and were followed for at least two years after their surgery. Main outcome measure The rates of various surgical complications within 90 days (venous thromboembolism, death) and within two years (infection, dislocation, periprosthetic fracture, revision) of surgery. Results Multivariate splines were developed to visualize the relation between surgeon volume and the risk for various complications. A threshold of 35 cases a year was identified, under which there was an increased risk of dislocation and revision. 6716 patients whose total hip arthroplasty was carried out by surgeons who had done ≤35 such procedure in the previous year were successfully matched to patients whose surgeon had carried out more than 35 procedures. Patients in the former group had higher rates of dislocation (1.9% v 1.3%, P=0.006; NNH 172) and revision (1.5% v 1.0%, P=0.03; NNH 204). Conclusions In a cohort of first time recipients of total hip arthroplasty, patients whose operation was carried by surgeons who had performed 35 or fewer such procedures in the year before the index procedure were at increased risk for dislocation and early revision. Surgeons should consider performing 35 cases or more a year to minimize the risk for complications. Furthermore, the methods used to visualize the relationship between surgeon volume and the occurrence of complications can be easily applied in any jurisdiction, to help inform and optimize local healthcare delivery.

Rate of and Risk Factors for Reoperations After Open Reduction and Internal Fixation of Midshaft Clavicle Fractures: A Population-Based Study in Ontario, Canada.

BACKGROUND Reoperation rates following open reduction and internal fixation (ORIF) of midshaft clavicle fractures have been described, but reported rates of nonunion, malunion, infection, and implant removal have varied. We sought to establish baseline rates of, and risk factors for, reoperations following clavicle ORIF in a large population cohort. METHODS Administrative databases were used to identify patients sixteen to sixty years of age who had undergone an ORIF of a closed, midshaft clavicle fracture from April 2002 to April 2010. The primary outcome was a reoperation within two years (isolated implant removal, irrigation and debridement [deep infection], pseudarthrosis reconstruction [nonunion], or clavicle osteotomy [malunion]). The secondary outcome was rare perioperative complications, including pneumothorax, subclavian vasculature injury, and brachial plexus injury. A multivariable logistic regression analysis was performed to determine the influence of patient and provider factors on these outcomes. RESULTS We identified 1350 patients who underwent midshaft clavicle ORIF (median age, thirty-two years [interquartile range, twenty-one to forty-four years]; 81.3% male). One in four patients (24.6%) underwent at least one clavicle reoperation. The most common procedure was isolated implant removal (18.8%), and females were at highest risk (odds ratio [OR], 1.7; p = 0.002). The median time to implant removal was twelve months. A reoperation secondary to nonunion, deep infection, and malunion occurred in 2.6%, 2.6%, and 1.1% of the patients after a median of six, five, and fourteen months, respectively. Risk factors for clavicle nonunion included female sex (OR, 2.2; p = 0.04) and a high comorbidity score (OR, 2.8; p = 0.009). For surgeons, fewer years in practice was associated with a small risk of the patient developing an infection (OR, 1.1; p < 0.001). Sixteen pneumothoraces (1.2%) were identified; however, brachial plexus and subclavian vessel injuries were each found in five or fewer patients. CONCLUSIONS Following clavicle ORIF, one in four patients underwent a reoperation. The most common procedure was implant removal, and although the rates of reoperations secondary to nonunion, malunion, and infection were low they were higher than previously reported. Pneumothoraces and neurovascular injuries were infrequent and should continue to be considered rare complications of clavicle ORIF. LEVEL OF EVIDENCE Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

A matched-cohort population study of reoperation after meniscal repair with and without concomitant anterior cruciate ligament reconstruction.

Background: Evidence for the success of a meniscal repair performed alone versus combined with anterior cruciate ligament reconstruction (ACLR) is equivocal. No large-scale comparative studies exist regarding this issue. Hypothesis: In the general population, meniscal repair in a presumed stable knee has the same rate of reoperation as meniscal repair performed with ACLR. Study Design: Cohort study; Level of evidence, 3. Methods: All meniscal repairs performed with ACLR in Ontario, Canada, between July 2003 and March 2008 in patients aged 15 to 60 years were identified using administrative billing, diagnostics, and procedural coding. This cohort was matched 1:1 for sex, age, and calendar year of surgery with a cohort of patients who underwent meniscal repair alone. The McNemar test of matched pairs was used to compare reoperation rates (debridement or repair) within 2 years of the index procedure. Conditional logistic regression analysis was used to identify potential risk factors for reoperation among unmatched patient (socioeconomic status surrogate, comorbidity) and provider (surgeon volume, academic hospital status) factors. Results: Of 1332 patients who underwent meniscal repair and ACLR, 1239 (93%) were matched with patients who underwent meniscal repair alone. The rate of meniscal reoperation was 9.7% in the combined cohort compared with 16.7% in the repair alone cohort (P < .0001). In the regression analysis, only ACLR was protective against meniscal reoperation (odds ratio, 0.57; P < .0001). Surgeon volume of meniscal repair did not influence outcome. Conclusion: A meniscal repair performed in conjunction with ACLR carries a 7% absolute and 42% relative risk reduction of reoperation after 2 years compared with isolated meniscal repair.

The risk of knee arthroplasty following cruciate ligament reconstruction: a population-based matched cohort study.

BACKGROUND Evidence regarding the risk of end-stage osteoarthritis following cruciate ligament reconstruction is based upon small sample sizes and radiographic, rather than clinical, criteria. The goals of this study were to determine the risk of knee arthroplasty, a surrogate for end-stage osteoarthritis, following cruciate ligament reconstruction, and to identify patient, provider, and surgical factors that influence knee arthroplasty risk. METHODS Using administrative databases, we identified all patients who were sixteen to sixty years of age and had undergone cruciate ligament reconstruction in Ontario from July 1993 to March 2008. Case patients were matched by demographic variables to five individuals without knee injury from the general population of Ontario, Canada, who had not undergone previous knee surgery, including cruciate ligament reconstruction. The main outcome was knee arthroplasty. Kaplan-Meier survival curves were generated for both cohorts. A Cox proportional hazards model determined those factors that influenced knee arthroplasty risk. RESULTS We identified 30,301 eligible patients who had undergone cruciate ligament reconstruction; of these patients, 30,277 were matched to 151,362 individuals from the general population; the median patient age was twenty-eight years and 65% of the patients were male. Primary anterior cruciate ligament reconstruction accounted for >98% of index cases. During the follow-up period, there was a significant difference (p < 0.001) between matched case and control cohorts with respect to the number of patients who underwent knee arthroplasty during the study period; in the matched case cohort, 209 patients underwent knee arthroplasty (event rate, 0.68 of 1000 person-years), and in the control cohort, 125 patients underwent knee arthroplasty (event rate, 0.10 of 1000 person-years). Moreover, fifteen years after cruciate ligament reconstruction (case cohort) or study enrollment (control cohort), there was a significant difference (p < 0.001) in the cumulative incidence of knee arthroplasty between the case cohort (1.4%) and the control cohort (0.2%). Age of fifty years or more (hazard ratio, 37.28; p < 0.001), female sex (hazard ratio, 1.58; p = 0.001), comorbidity score of ≥5 points (hazard ratio, 5.91; p = 0.002), surgeon annual volume of cruciate ligament reconstruction of twelve or fewer cases per year (hazard ratio, 2.53; p < 0.001), and cruciate ligament reconstruction undertaken in university-affiliated hospitals (hazard ratio, 1.51, p = 0.008) increased the odds of knee arthroplasty; however, male sex (hazard ratio, 0.63; p = 0.001) and patient age of less than twenty years (hazard ratio, 0.07; p = 0.009) were protective. Concurrent meniscal repair or debridement did not increase arthroscopy risk. CONCLUSIONS After fifteen years, the cumulative incidence of knee arthroplasty following cruciate ligament reconstruction was low (1.4%); however, it was seven times greater than the cumulative incidence of knee arthroplasty among matched control patients from the general population (0.2%). Older age, female sex, higher comorbidity, low surgeon annual volume of cruciate ligament reconstruction, and cruciate ligament reconstruction performed in a university-affiliated hospital were factors that increased knee arthroplasty risk.

The Epidemiology of Revision Anterior Cruciate Ligament Reconstruction in Ontario, Canada

Background: Knowledge of the rate of and risk factors for re-revision, reoperation, and readmission after revision anterior cruciate ligament reconstruction (ACLR) is limited. Purpose: To determine the rate of and risk factors for re-revision, reoperation, and readmission after revision ACLR. Study Design: Descriptive epidemiology study. Methods: All patients who underwent first revision ACLR in Ontario, Canada, from January 2004 to December 2010 were identified and followed until December 2012. Exclusions included age <16 years, previous osteotomy, or multiligament knee reconstruction. The main outcome was re-revision ACLR. Secondary outcomes included reoperation (irrigation and debridement [I&D], meniscectomy, manipulation under anesthesia, contralateral ACLR, and total knee arthroplasty) and readmission. Survival to re-revision was determined using the Kaplan-Meier approach. A Cox proportional hazards model or logistic regression were used to determine the influence of patient, surgical, and provider factors on outcomes. A post hoc analysis was performed to determine the influence of the aforementioned factors on postoperative infection risk. Results: Overall, 827 patients were included (median age, 30 years; 58.8% males). Single-stage revisions comprised 92.9% of cases, and a meniscal procedure (repair or debridement) was performed in 45.3% of cases. The re-revision rate at a mean follow-up of 4.8 ± 2.2 years was 4.4%, and the 5-year survival rate was 95.4%. The rates of I&D, meniscectomy, contralateral ACLR, and readmission were 0.8%, 3.1%, 3.4%, and 4.1%, respectively. Manipulation under anesthesia and total knee arthroplasty were rare. Young age significantly increased contralateral ACLR risk (risk decreased by 5.1% with each year of age >16 years; P = .02) but not re-revision ACLR risk. Low surgeon’s annual volume of revision ACLR (<4 revisions/year: odds ratio, 1.2; P = .02) and male sex (odds ratio, 13.3; P = .01) significantly increased overall infection risk; male sex also influenced I&D risk. Conclusion: Re-revision, reoperation, and readmission rates after revision ACLR were low, and the risk for I&D, infection, and contralateral ACLR were influenced by male sex, low surgeon volume, and young age, respectively. Clinical Relevance: This is the first study to determine morbidity rates and risk factors after revision ACLR, providing reference data from the general population.