Perioperative Periprosthetic Femur Fractures are Strongly Correlated With Fixation Method: an Analysis From the American Joint Replacement Registry.

BACKGROUND: Perioperative periprosthetic femur fractures (PPFx) after total hip arthroplasty (THA) remain a leading cause of early stem failure and revision and are associated with high rates of morbidity and mortality. American Joint Replacement Registry (AJRR) data have been analyzed to determine the relationship of femoral stem fixation to PPFx revision. METHODS: All early (≤3 months from index arthroplasty) linked primary and revision hip arthroplasties reported to the AJRR between 2012 and 2017 were analyzed. We evaluated patient demographics, arthroplasty type (hemiarthroplasty vs THA), and stem fixation. RESULTS: A total of 10,277 linked revisions were reported to the AJRR during 2012-2017. Early PPFx requiring revision occurred in 628 patients (6.1%) due to osteoarthritis (82.4%), femoral neck fracture (12.1%), and other causes (15.6%). Five hundred twenty-nine patients (84%) were treated with THA and 99 patients with hemiarthroplasty (16%). Females (70%) have a higher prevalence of revisions. Fifty-eight percent of patients were ≥70 years of age, and 20% were ≥80 years of age. Patients with cementless stems were 2.6 times (account 94.9% of the fractures, 95% confidence interval 0.59-11.1) more likely to undergo early revision for PPFx than those with cemented fixation, although not statistically significant with its sample size. CONCLUSION: Mirroring other studies and national registries, there was an association between cementless fixation and PPFx in AJRR. Nevertheless, AJRR data demonstrate a trend of increasing utilization of cementless femoral fixation for THA and hemiarthroplasty, with cementless fixation accounting for 93% of THA stems with early periprosthetic fracture. Additional analysis is needed to better understand this phenomenon, especially in the elderly.

Erratum to: Editorial: Do Orthopaedic Surgeons Belong on the Sidelines at American Football Games?

In the November Editorial, "Editorial: Do Orthopaedic Surgeons Belong on the Sidelines at American Football Games?" a statistic was attributed to a JAMA study (Ref. 10) that should have been attributed to an article from the New York Times (Ref. 16). The sentence in question should read: "We accept that critique, provided that the skeptics acknowledge that the best-case estimate in support of the safety of football would result in a CTE prevalence estimate of 9%, since only another 1200 ex-NFL players have died [16] since this research group [10] began studying football players' brains."

Does operative time affect infection rate in primary total knee arthroplasty?

BACKGROUND: Prolonged operative time may increase the risk of infection after total knee arthroplasty (TKA). Both surgeon-related and patient-related factors can contribute to increased operative times. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) whether increased operative time is an independent risk factor for revision resulting from infection after TKA; (2) whether increasing body mass index (BMI) increased operative time; and (3) whether increasing experience substantially decreased operative time. METHODS: We retrospectively evaluated primary TKAs from our joint registry between March 2000 and August 2012. Cox proportional hazard models were used to assess the relationship between operative time and revision resulting from infection after accounting for age, sex, BMI, and Agency for Healthcare Research and Quality comorbidity score. Of 9973 instances of primary TKA, 73 underwent revision surgery for infection (0.73%). RESULTS: After accounting for the confounders of age and sex, operative time was not found to have a significant effect; a 15-minute increase in operative time increased the hazard of revision resulting from infection by only 15.6% (p=0.053; 95% confidence interval, 0.0%-34.0%). In addition, a five-unit increase in BMI was found to increase mean operative time by 1.9 minutes, on average, regardless of sex (p<0.0001). Operative time decreases with increasing experience but appears to plateau at approximately 300 surgeries. CONCLUSIONS: Operative time is only one of many factors that may increase infection risk and may be influenced by numerous confounders. Increasing BMI increased operative time but the effect was modest. The effect of increasing experience on operative duration of this common procedure was surprisingly limited among our surgeons. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

International comparative evaluation of knee replacement with fixed or mobile-bearing posterior-stabilized prostheses.

BACKGROUND: Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design. METHODS: Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis. RESULTS: This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had a significantly higher hazard ratio (1.86) than did the fixed-bearing posterior-stabilized prostheses (95% confidence interval, 1.28 to 2.7; p = 0.001). For all other time intervals, the mobile-bearing posterior-stabilized prostheses had higher hazard ratios; however, these differences were not significant. CONCLUSIONS: Mobile-bearing posterior-stabilized prostheses had an increased rate of revision compared with fixed-bearing posterior-stabilized prostheses. This difference was evident in the first year.

Assessment of moral reasoning skills in the orthopaedic surgery resident applicant.

BACKGROUND: Assessing orthopaedic surgery residency applicants is a complex process. One important applicant characteristic not commonly measured during the interview process is moral behavior, a key component of the guidelines of the Accreditation Council for Graduate Medical Education for professionalism competency. We sought to determine whether a relationship exists between the results of residency selection interviews, as measured by match rank order, and moral reasoning skills, as measured by the revised version of the Defining Issues Test (DIT-2). METHODS: The DIT-2, a psychological tool that has been validated in assessing moral reasoning in >30,000 subjects, was administered to orthopaedic surgery residency candidates on a voluntary basis during their interview day. Data were collected annually from four applicant classes (2009 to 2012) at one institution. Each candidate was interviewed by an orthopaedic faculty team and was ranked comparatively with the other interviewing applicants. The five-part aggregate interview method for ranking applicants for the match list included a focused interview station presenting ethical dilemmas as one part of determining rank order. RESULTS: One hundred and twenty-four fourth-year medical students interviewing for orthopaedic surgery residency were assessed with the DIT-2. The results from the DIT-2 produced a postconventional score, which correlates with various levels of moral development. Each applicant's postconventional score was then compared with the patient's overall rank order. Applicants had highly variable moral reasoning skills, with no relationship to the final rank list. CONCLUSIONS: Despite a wide range of DIT-2 scores, the interview process did not differentiate applicants based on moral reasoning skills. It remains unclear whether the DIT-2 could (or should) be used as an additional data point to help stratify orthopaedic residency applicants and to predict their performance.

Risk factors for periprosthetic joint infection following primary total hip arthroplasty: a case control study.

The purpose of this study was to identify the specific comorbidities and demographic factors that are independently associated with an increased risk of periprosthetic joint infection (PJI) in total hip arthroplasty (THA) patients. A case-control study design was used to compare 88 patients who underwent unilateral primary THA and developed PJI with 499 unilateral primary THA patients who did not develop PJI. The impact of 18 comorbid conditions and other demographic factors on PJI was examined. Depression, obesity, cardiac arrhythmia, and male gender were found to be independently associated with an increased risk of PJI in THA patients. This information is important to consider when counseling patients on the risks associated with elective THA, and for risk-adjusting publicly reported THA outcomes.

Efficacy of revision surgery for the dislocating total hip arthroplasty: report from a large community registry.

BACKGROUND: Historically, achieving stability for the unstable total hip arthroplasty (THA) with revision surgery has been achieved inconsistently. Most of what we know about this topic comes from reports of high-volume surgeons' results; the degree to which these results are achieved in the community is largely unknown, but insofar as most joint replacements are done by community surgeons, the issue is important. QUESTIONS/PURPOSES: We used a community joint registry to determine: (1) the frequency of repeat revision after surgery to treat the unstable THA; (2) what surgical approaches to this problem are in common use in the community now; (3) are there differences in repeat revision frequency that vary by approach used; and (4) has the frequency of repeat revision decreased over time as surgical technique and implant options have evolved? METHODS: We reviewed 6801 primary THAs performed in our community joint registry over the last 20 years. One hundred eighteen patients (1.7%) with a mean age of 67 years were revised within the registry for instability/dislocation. Failure was defined as a return to the operating room for rerevision surgery for instability. Minimum followup was 2 years (average, 9.4 years; range, 2-20 years) with six patients having incomplete followup. The frequency of rerevisions was calculated and compared using Pearson's chi-square test. Cumulative rerevision rates were calculated using the Kaplan-Meier method and types of revision procedures were compared using the log-rank test. RESULTS: The initial revision procedure was successful in 108 patients (92%); 10 patients underwent repeat surgery for recurrent dislocation after their initial revision surgery. The most frequently performed procedure was revision of the head and liner only (35 of 118 [30%]); constrained devices were used in 19% (22 of 118) of the procedures. There was no difference in the cumulative rerevision rates for instability or dislocation by type of revision procedure performed. Six of 22 constrained liners were rerevised for varying indications. There was no difference in frequency of repeat revision for instability between those patients revised for THAs performed before 2003 and those managed more recently. CONCLUSIONS: Revision surgery for unstable THA is successfully managed in the community with a variety of surgical interventions. Identifying the reason for dislocation and addressing the source remain paramount. Constrained liners should be used with caution; although typically used in the most problematic settings, rerevision for a variety of failure modes remains troublesome. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.