Faculty Bibliography

This symposium from the 2025 American Association of Hip and Knee Surgeons (AAHKS) Annual Meeting contains an overview of concepts and techniques to use during revision total hip arthroplasty (THA).

Infection remains one of the most catastrophic complications following orthopaedic surgery. Despite substantial advances in molecular diagnostics, biomarker assays, and consensus definitions, accurately diagnosing orthopaedic infection continues to challenge even the most experienced clinicians. There are differences in the diagnosis and treatment of infections that are related to different anatomic regions. The difficulty arises from the inherent biological diversity of infecting organisms and surgical locations, variable host responses, and the absence of a true diagnostic "gold standard." This article summarizes the current diagnostic challenges and emerging solutions, drawing on recent high-impact evidence and consensus frameworks.

BACKGROUND/UNASSIGNED:The purpose of this study was to assess the demographic characteristics of orthopaedic surgeons in Louisiana taking care of patients with Medicaid insurance and to assess any perceived barriers to care, with a focus on total joint arthroplasty (TJA). METHODS/UNASSIGNED:An electronic survey was distributed to all practicing surgeon members of the Louisiana Orthopaedic Association with questions about practice type, subspecialty, demographics, estimated percentage of Medicaid patient volume, and perceived barriers to care. Responses were collected using a secure database, and statistical analysis was performed. RESULTS/UNASSIGNED:= .0001). CONCLUSIONS/UNASSIGNED:Most orthopaedic surgeons performing TJA in Louisiana either do not accept or perform a relatively small percentage of their practice volume on patients with Medicaid insurance. Low physician and facility reimbursement rates and difficulty referring to ancillary services were perceived as the greatest barriers to caring for these patients.

BACKGROUND:Physicians may choose to opt out of accepting reimbursements through the Medicare program. There is limited information on arthroplasty surgeons who elect to opt out of Medicare. METHODS:The public Centers for Medicare & Medicaid Services (CMS) Opt-Out Affidavits Dataset was used to identify individual orthopaedic surgeons performing hip and knee arthroplasty who had opted out of Medicare as of February 2024. Publicly available internet pages were used to investigate individual surgeon characteristics and evaluate trends among those surgeons who opted out of Medicare over time. RESULTS:Of the 308 orthopaedic surgeons who did not accept Medicare, 85 performed hip and/or knee arthroplasty. Of these surgeons, 37% practiced in or near New York City, while 27% practiced in the Southwest United States. All practiced in urban areas. At the time of opt out, physicians had an average time in practice of 21.3 years and a median of 20 years (range, five to 46). Surgeons had an average H-index of 17.6 and a median of six (range, zero to 82). Approximately half of the surgeons were fellowship-trained in arthroplasty. Of these, 39% completed their training at the same institution. Surgeons received a mean of $377,178 and a median of $2,520 (range, zero to $10,631,606) from industry payments in the most recent year. This includes 47 (56%) who received less than $5,000 and nine (11%) who received over $1,000,000. In addition, 53% accepted insurance plans other than Medicare, and 25% had ownership of outpatient surgery centers. Also, the annual incidence of arthroplasty surgeon opt outs was higher in 2023 than in any year previously. CONCLUSION/CONCLUSIONS:Arthroplasty surgeons who opt out of Medicare have diverse demographic, academic, and financial characteristics. Features commonly shared were geographic location and fellowship institution, while other characteristics vary substantially.

The American Joint Replacement Registry continues to grow, as represented by the 4.3 million hip and knee arthroplasties analyzed in the 2024 American Joint Replacement Registry Annual report. Highlights of this report are found in the following article. We encourage readers to access the full report at https://www.aaos.org/registries/publications/ajrr-annual-report/.

BACKGROUND:Patients with Medicaid insurance are at an increased risk of postoperative complications following total knee arthroplasty and total hip arthroplasty (TJA); however, their outcomes following revision TJA for periprosthetic joint infection (PJI) requires further study. METHODS:A retrospective query was conducted for adult patients undergoing implant explantation and antibiotic spacer placement for TJA PJI from the Premier Healthcare Database between December 1, 2016, and December 31, 2021. Patients were then grouped by Medicaid or non-Medicaid insurance status and were age matched through exact caliper matching. Multivariable regression models addressed potential confounding. Adjusted risks of 90-day postoperative complications were reported. RESULTS:Of the 40,346 patients identified, 2,711 Medicaid patients were matched to 10,844 non-Medicaid patients on age (56.1 vs. 56.1 years, P = 1.000). Patients with Medicaid experienced higher risk of sepsis (adjusted odds ratio [aOR] = 1.20, P = 0.010), readmission (aOR = 1.12, P = 0.022), being discharged to a skilled nursing facility (aOR = 1.13, P = 0.031), and had longer length of stay (9.48 vs. 6.67 days, P < 0.001), compared with patients with non-Medicaid. Medicaid patients had a higher rate of inpatient mortality (0.81% vs. 0.48%, P = 0.038); however, the risk was similar after accounting for differences in comorbidities. CONCLUSION/CONCLUSIONS:Following revision TJA for PJI, patients with Medicaid were at an increased risk for postoperative complication, including sepsis and readmission. They experienced a higher rate of inpatient mortality that may be driven by differences in comorbidities. Insurers and policy makers should consider this information to develop risk stratification-based payment strategies that take into account the healthcare burden of this high-risk patient population. LEVEL OF EVIDENCE/METHODS:IV.

INTRODUCTION/BACKGROUND:The relationship between surgeon volume and risk of dislocation after total hip arthroplasty (THA) is debated. This study sought to characterize this association and assess patient outcomes using a nationwide patient and surgeon registry. METHODS:The Premier Healthcare Database was queried for adult primary elective THA patients from January 1, 2016, to December 31, 2019. Annual surgeon volume and 90-day risk of dislocation were modeled using multivariable logistic regression with restricted cubic splines. Bootstrap analysis identified a threshold annual case volume, corresponding to the maximum decrease in dislocation risk. Surgeons with an annual volume greater than the threshold were deemed high volume, and those with an annual volume less than the threshold were low volume. Each surgeon within a given year was treated as a unique entity (surgeon-year unit). 90-day complications of patients treated by high-volume and low-volume surgeons were compared. RESULTS:From 2016 to 2019, 352,131 THAs were performed by 5,106 surgeons. The restricted cubic spline model demonstrated an inverse relationship between risk of dislocation and surgeon volume (threshold: 109 cases per year). A total of 9,967 (87.8%) low-volume surgeon-year units had individual dislocation rates lower than the average of the entire surgeon cohort. Patients treated by high-volume surgeons had decreased risk of dislocation (adjusted odds ratio [aOR], 0.60; 95% CI, 0.54 to 0.67), periprosthetic fracture (aOR, 0.87; 95% CI, 0.76 to 0.99), periprosthetic joint infection (aOR, 0.63; 95% CI, 0.56 to 0.69), readmission (aOR, 0.70; 95% CI, 0.67 to 0.73), and in-hospital death (aOR, 0.60; 95% CI, 0.46 to 0.80). CONCLUSION/CONCLUSIONS:While most of the low-volume surgeons had dislocation rates lower than the cohort average, increasing annual surgeon case volume was associated with a reduction in risk of dislocation after primary elective THA. THERAPEUTIC LEVEL OF EVIDENCE/UNASSIGNED:Level IV.

BACKGROUND/UNASSIGNED:Electronic medical record portals enable real-time communication between patients and surgeons after total knee arthroplasty (TKA). This study evaluated the impact of message timing and frequency on postoperative outcomes and patient-reported outcome measures (PROMs). MATERIALS AND METHODS/UNASSIGNED:We retrospectively reviewed 9,353 primary TKAs performed at a single academic institution. Of these, 1,219 patients sent messages within 2 weeks of surgery (early), 507 sent messages between 2 and 8 weeks (late), and 7,627 did not message. RESULTS/UNASSIGNED:< .001). There was no difference in PROMs regardless of message timing, and there was no association between the number of messages sent and perioperative outcomes or PROMs. CONCLUSION/UNASSIGNED:Older age and longer LOS were associated with less patient-initiated contact after TKA. Older patients may be less familiar with digital platforms and less likely to send messages. Early messaging may reflect heightened recognition of postoperative issues, enabling counseling or intervention and reducing readmissions. These findings underscore the importance of preoperative education and equitable access, though long-term effects of messaging warrant further study.