Faculty Bibliography

BACKGROUND/UNASSIGNED:Periprosthetic joint infections (PJIs) following primary and revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA) have been studied, but a contemporary large-scale analysis of incidence has not been performed. This study assessed PJI incidence and trends for TKA, THA, rTKA, and rTHA using a contemporary database. METHODS/UNASSIGNED:Epic Cosmos database was retrospectively queried (2015-2023). Current procedureal terminology codes identified patients: 27447 (TKA), 27130 (THA), 27486 (rTKA one component), 27487 (rTKA both components), 27134 (rTHA both components), 27137 (rTHA acetabular component), and 27138 (rTHA femoral component). PJI rates were identified using International Classification of Diseases 9/10 codes and analyzed using linear regression. RESULTS/UNASSIGNED:= .08). CONCLUSIONS/UNASSIGNED:Significant PJI reduction after primary TKA and THA was observed over the last decade, but infection rates remained stable in revision cohorts. Further investigations are required to assess underlying reasons for observed PJI rate reductions following primary arthroplasty.

BACKGROUND:The impact of postoperative antithrombotic therapy (ATT) on complications such as periprosthetic joint infection (PJI) after total knee and hip arthroplasty (TKA and THA, respectively) remains understudied. We aimed to evaluate temporal trends in ATT use and the association between ATT type and PJI following primary TKA and THA. METHODS:We retrospectively reviewed 20,376 TKA and 16,076 THA patients receiving postoperative ATT between 2013 and 2025. Trends in ATT use were analyzed for all patients, but PJI incidence (2018 International Consensus Meeting definition) was assessed only in patients who had a minimum 90-day follow-up (14,663 TKA; 11,445 THA). Of these, 0.8% and 1.3% developed a PJI, respectively. Multivariate logistic regressions adjusted for age, sex, body mass index, smoking, and the Charlson Comorbidity Index were applied to assess the association between ATT and PJI. RESULTS:From 2013 to 2025, aspirin monotherapy increased to account for the majority of prophylaxis (TKA: 2.0 to 59.4%; THA: 3.1 to 82.2%). In contrast, the use of low-molecular-weight heparin (LMWH) declined (TKA: 87.6 to 0.8%; THA: 86.7 to 2.3%), as did warfarin (TKA: 4.1 to 0.3%; THA: 3.4 to 0.9%) and rivaroxaban (TKA: 6.8 to 4.2%; THA: 8.9 to 2.8%). During the same period, apixaban use increased (TKA: 0 to 10.0%; THA: 0 to 12.7%). Aspirin monotherapy was associated with lower odds of PJI compared to non-aspirin regimens (adjusted odds ratio [OR] 0.60, 95% confidence interval [CI] 0.45 to 0.81, P = 0.001). Conversely, warfarin (OR 8.01, 95% CI 3.41 to 18.88, P < 0.001) and LMWH (OR 1.89, 95% CI 1.35 to 2.64, P < 0.001) were independently associated with increased PJI risk in THA. CONCLUSION/CONCLUSIONS:Aspirin has become the dominant postoperative ATT agent. In THA, aspirin is associated with a significantly decreased risk of PJI compared to potent anticoagulants like warfarin and LMWH, while no such association was found in the TKA cohort. Surgeons should prioritize aspirin to minimize postoperative infection risk.

BACKGROUND:Prolonged retention of antibiotic-loaded articulating spacers after the first stage of a two-stage revision for periprosthetic joint infection (PJI) can occur because of patient preference, surgeon preference, or medical reasons that prevent the planned second stage. Little is known about the frequency of persistent infections, mechanical complications, and functional results in patients with retained spacers. QUESTIONS/PURPOSES/OBJECTIVE:At a minimum follow-up of 2 years after spacer placement, among patients who do not undergo the second stage revision (replacement of the spacer with a definitive prosthesis of the hip or knee): (1) What was the survival of the spacer free from unplanned reoperation or removal, the cumulative incidence of symptomatic infection, and the overall (Kaplan-Meier) survivorship of the patients? (2) What is the cumulative incidence of mechanical complications (spacer fracture or dislocation)? (3) What is the ambulatory status of patients who have retained their spacers? METHODS:Between March 2011 and July 2023, a total of 111 and 152 patients underwent first-stage revision with an articulating spacer placement as part of a planned two-stage procedure for chronic PJI after THA and TKA at our institution, respectively. Of these, 21% (23 of 111) in the THA group and 24% (37 of 152) in the TKA group did not undergo the anticipated second-stage reimplantation at our institution at least 1 year after spacer placement. Among the original cohorts, 2% (2 of 111) of patients who underwent THA and 3% (4 of 152) of patients who underwent TKA subsequently underwent second-stage reimplantation at outside institutions when reviewed, leaving 19% (21 of 111) in the THA group and 22% (33 of 152) in the TKA group with retained spacers. Of the original cohorts, 7% (8 of 111) in the THA group and 5% (8 of 152) in the TKA group did not have a 2-year follow-up, leaving 12% (13 of 111) of patients with THA and 16% (25 of 152) of patients with TKA available for analysis with a minimum of 2 years of follow-up or death in this retrospective study. The median (range) follow-up from spacer placement to the latest follow-up was 5 years (2 to 11) for patients with THA and 4 years (2 to 8) for patients with TKA. In the THA cohort, the median (range) age was 72 years (59 to 86), and eight patients were female; the median BMI was 32 kg/m2, and the median Charlson comorbidity index (CCI) was 3.5. In the TKA cohort, the median (range) age was 69 years (45 to 83), 13 patients were female, the median BMI was 31 kg/m2, and the median CCI was 4. Complication data following spacer placement were obtained from the electronic medical record and by telephone follow-up when needed. Clinical symptoms (swelling, erythema, warmth, fever, drainage, sinus tract, and pain), inflammatory markers (C-reactive protein and erythrocyte sedimentation rate), available radiographic findings, and laboratory test results (including synovial fluid analysis when obtained) were reviewed for evidence of infection or spacer-related mechanical failure. Infection after the spacer placement was defined as failure when the treating surgeon determined that an unplanned return to the operating room or spacer removal was warranted, acknowledging that postoperative evaluation thresholds varied among surgeons. Spacer-related mechanical failure was defined as spacer fracture or dislocation leading to reoperation or spacer removal. Patients were classified based on whether they underwent an unplanned reoperation or spacer removal. Patients who did not undergo unplanned reoperation or spacer removal were further categorized based on use of chronic suppressive antibiotics (decisions regarding chronic antibiotic therapy were made by the treating surgeon and/or infectious disease team). Patients who underwent reoperation were those who returned to the operating room because of concerning clinical, imaging, and/or laboratory findings of infection or mechanical complications, and the treating surgeon decided to proceed with revision surgery. All reoperation decisions were made by fellowship-trained arthroplasty surgeons with high-volume experience in two-stage revision. We used a competing-risks model to estimate survival of the spacer free from unplanned reoperation or removal attributable to infection or mechanical complications (calculated as 1 minus the corresponding cumulative incidence), with death treated as a competing event. Kaplan-Meier analysis was used to estimate patient survivorship, with death as the endpoint. Mortality data were obtained from medical records and hospital databases and were confirmed by telephone follow-up with family members and public records when needed. Ambulatory status before and after spacer placement was summarized descriptively and reported only for patients with both prespacer and postspacer data available (10 THAs and 25 TKAs); no formal hypothesis testing was performed for ambulatory or functional measures. RESULTS:At 2 years of follow-up, the survival of the spacer free from unplanned reoperation or removal was 89% (95% confidence interval [CI] 80% to 99%) for patients with THA and TKA combined, the cumulative incidence of infection was 5% (95% CI 0% to 12%), and the Kaplan-Meier survivorship of the patients was 92% (95% CI 84% to 100%). The cumulative incidence of mechanical complications (spacer fracture or dislocation) was 5% (95% CI 0% to 13%). In the THA cohort (10 patients), ambulatory status before the first stage included two patients using a wheelchair, two using a walker, one using crutches, two using a cane, and three walking without assistive devices. At latest follow-up, four patients used a wheelchair, two used a walker, two used a cane, and two walked without assistive devices. In the knee cohort (25 patients), ambulatory status before the first stage included two patients using a wheelchair, five using a walker, 13 using a cane, and five walking without assistive devices. At latest follow-up, two patients used a wheelchair, five used a walker, 13 used a cane, and five walked without assistive devices. CONCLUSION/CONCLUSIONS:Retained articulating spacers can provide infection control in selected patients who do not proceed to reimplantation after first-stage spacer placement for PJI. Although infection-free spacer survival is achievable, these patients remain at risk for mechanical complications, including dislocation and fracture, as well as progressive functional decline. These risks should be clearly discussed during preoperative counseling to align expectations and support informed decision-making. Further studies are needed to refine patient selection, improve spacer durability, and standardize definitions of treatment success in PJI. LEVEL OF EVIDENCE/METHODS:Level III, case series.

BACKGROUND:This study compares clinical and functional outcomes between simultaneous hardware removal during total knee arthroplasty (TKA) and staged TKA after prior hardware removal. METHODS:We retrospectively reviewed 155 patients who had prior knee hardware and underwent elective primary TKA between 2012 and 2024 at an urban academic institution. Patients were categorized into "simultaneous" removal during TKA (n = 127) or "staged" TKA after removal (n = 28), and stratified by hardware type (minor/moderate/major). RESULTS:Simultaneous procedures involved significantly less "major hardware," single incisions, and tibial stem extensions than staged procedures (32.3 versus 78.6%, P < 0.001; 81.9 versus 100%, P = 0.007; and 0.8 versus 10.7%, P = 0.019, respectively). Hardware, particularly the major type, was more often retained or partially retained in the simultaneous group (48.0 versus 21.4%, P = 0.008). Reoperation, revision, and infection rates did not significantly differ based on timing or hardware location. Simultaneous patients had smaller 3-month Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Intensity and Interference score reductions (-1.6 versus -9.9, P = 0.006 and +0.4 versus - 7.2, P = 0.007, respectively), but greater 2-year Knee Injury and Osteoarthritis Outcome Score for Joint Replacement improvements (+25.0 versus - 1.1, P = 0.006) compared to staged patients. Simultaneous major hardware removal demonstrated significantly greater 2-year Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and PROMIS Pain Interference improvement (+32.0 versus -5.5, P = 0.001, and -6.2 versus +5.8, P = 0.027, respectively), but smaller 2-week PROMIS Pain Intensity score reduction (+2.2 versus -4.9, P = 0.050) compared to staged procedures. CONCLUSIONS:Simultaneous hardware removal during TKA led to higher retained major hardware rates and fewer single incisions than staged procedures, without increased reoperation or revision risks. Despite higher 3-month pain scores, simultaneous surgery achieved greater 2-year functional improvement, suggesting it offers advantages for select patients.

BACKGROUND:Periprosthetic joint infection (PJI) remains one of the most challenging complications after total joint arthroplasty (TJA). While conventional culture remains the standard for identification of causative pathogens in PJI, rapid identification techniques such as polymerase chain reaction (PCR) are becoming increasingly popular, with little comparative data. METHODS:A retrospective review was performed on a database of consecutive patients who underwent workup for PJI at a tertiary referral center from January 1, 2023, to May 31, 2025. Patients who underwent both standard synovial fluid culture and a PCR panel on the same day were included. Synovial fluid culture was used as the reference standard, and test result concordance and turnaround time were assessed. RESULTS:Results from the PCR panel showed strong agreement with synovial fluid culture in the 225 cases analyzed, with 88% culture-positive agreement. The PCR false negatives were due to organisms not included in the PCR panel (n = six), a false-positive culture from contamination (n = one), and a patient who had a PJI due to Candida parapsilosis (n = two). When only considering true positives with organisms included in the panel, the PCR displayed a 97.1% culture-positive agreement. The panel also detected organisms in eight culture-negative cases (94.7% culture-negative agreement). Those cases each met the 2018 International Consensus Meeting definition of PJI, were treated as PJIs, and their negative culture results were hypothesized to be due to antibiotic use before culture. The panel's turnaround time (TAT) (median 8.4 hours) is significantly faster than both culture-positive (P < 0.001) (69.2 hours) and culture-negative (P < 0.001) (139.5 hours) results from synovial fluid culture. CONCLUSIONS:The high concordance between the panel and conventional culture techniques suggests that PCR may be added as an adjunctive diagnostic tool for PJI workup after TJA. Our results also suggest that PCR may be more accurate than fluid culture in patients who have current antibiotic usage. The PCR's advantage of rapid TAT is particularly helpful in the timely optimization of antibiotic therapy.

BACKGROUND:The increasing prevalence of chronic antithrombotic medication use among aging and medically complex total joint arthroplasty (TJA) patients poses major challenges, requiring a careful balance of thrombotic and bleeding risks. METHODS:This review aimed to summarize existing guidelines and supporting literature surrounding the perioperative management of chronic antithrombotics in patients undergoing TJA and identify remaining gaps and challenges to guide future research efforts. RESULTS:Current guidelines strongly recommend continuing aspirin throughout the perioperative period for TJA patients while advising the cessation of P2Y12 inhibitors and anticoagulants preoperatively, with specific timing dependent on patient- and procedure-related risks. There remains a critical gap in high-quality evidence and standardized guidelines regarding optimal postoperative resumption of chronic antithrombotics, leading to wide variability in practices and reliance on surgeon judgment. CONCLUSIONS:Future research efforts should prioritize developing evidence-based perioperative protocols tailored specifically for TJA patients on chronic antithrombotic therapy, similar to existing multidisciplinary guidelines for immunosuppressive management.

BACKGROUND:The purpose of this study was to compare hospital quality and patient outcomes of hip arthroplasty for femoral neck fractures (FNFs) based on the subspecialty training of the treating surgeon: orthopaedic trauma (OT) versus adult reconstruction (AR) fellowship training. METHODS:A retrospective review was conducted on 1,008 elderly patients treated for an FNF with hemiarthroplasty or total hip arthroplasty between 2014 and 2024. Patients were grouped by their surgeon's subspecialty training (OT versus AR). Outcomes analyzed included length of stay, complications, 30-day and 90-day readmissions, dislocations, infections, and 30-day mortality. Statistical significance was set at P < 0.05. RESULTS:Baseline patient demographics were similar between groups, except for a higher proportion of women in the AR cohort (P = 0.008) and Black patients in the OT cohort (P = 0.016). Although age-unadjusted Charlson Comorbidity Index (CCI) was significantly higher in the AR group (P = 0.046), Score for Trauma Triage in the Geriatric and Middle Aged (STTGMA) scores, which take CCI and other health factors into account, were not significantly different (P = 0.59). In-hospital outcomes, including length of stay (P = 0.89) and minor and major complication rates (P = 0.38, P = 0.38), demonstrated no significant differences between groups. Post-discharge outcomes, including readmissions (30-day: P = 0.52, 90-day: P = 0.16), infections (P = 0.25), dislocations (P = 0.89), and 30-day mortality (P = 0.14), were also similar. CONCLUSION/CONCLUSIONS:No differences were identified in any of the outcomes analyzed between OT-trained and AR-trained surgeons in our study. This suggests that when FNFs are treated at high-volume academic institutions, subspecialty training may not substantially influence the short-term results of FNFs treated with hip arthroplasty. These findings highlight the importance of timely surgical intervention rather than waiting for a particularly trained surgeon to be available.

BACKGROUND:Historically, total knee arthroplasty (TKA) used resection and balancing techniques to target symmetric medial and lateral gaps throughout range of motion (ROM). With modern awareness on alternate alignment concepts, one area of ongoing debate is whether asymmetric medial and lateral compartment gaps improve outcomes. Proponents of an asymmetric looser lateral compartment gap philosophy postulate that this phenotype recreates native knee kinematics with lateral femoral condylar rollback pivoting through a tighter medial compartment during knee flexion. The purpose of this study was to compare patient-reported outcomes (PROs) and ROM with respect to symmetric or asymmetric gaps. METHODS:We performed a systematic review and random-effects meta-analysis of prospective and retrospective studies. We compiled all comparative studies reporting symmetric and asymmetric gaps, irrespective of directional or nondirectional gap asymmetry. However, we performed a meta-analysis only between a cohort of directional asymmetric gaps (looser lateral than medial gap) and symmetric gaps (equal medial and lateral gaps). Gaps were compared in flexion and extension. ROM and PROs were evaluated through standardized mean difference (SMD), with statistical significance defined by 95% confidence interval (CI). RESULTS:A total of 17 studies with 3,319 knees were included. Four studies reported nondirectional gap asymmetry, whereas 13 studies reported directional gap asymmetry, of which 8 shared common outcome variables and were therefore included in the meta-analysis. Analysis of gaps in flexion revealed significantly increased ROM favoring asymmetric looser lateral gaps over symmetric gaps (SMD -0.19, 95% CI -0.29 to -0.09). Analysis of gaps in extension also revealed increased ROM favoring asymmetric looser lateral gaps (SMD -0.10, 95% CI -0.36 to 0.16). Finally, the Forgotten Joint Score (FJS) favored looser lateral gaps in flexion over symmetric gaps (SMD -0.13, 95% CI -0.41 to 0.15). However, differences in the latter 2 were nonsignificant. CONCLUSION/CONCLUSIONS:This is the first meta-analysis evaluating the postoperative outcomes as a function of symmetric vs. asymmetric mediolateral gaps. We report improved FJS and ROM favoring asymmetric looser lateral gaps in flexion. LEVEL OF EVIDENCE/METHODS:Therapeutic Level II, systematic review of Level II and III and IV studies. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Large-diameter head total hip arthroplasty (LDH-THA) emerged in the late 1990s as a stemmed alternative to hip resurfacing arthroplasty (HRA). Both procedures use metal-on-metal (MoM) bearings to permit larger heads, lower dislocation risk, and optimize function in younger, active patients. While concerns over metal ion release and adverse local tissue reactions curtailed MoM use, long-term follow-up remains critical for the substantial population with these devices in situ. This review compares LDH-THA and HRA in clinical outcomes, metal ion levels, and revision rates to guide long-term management and future implant design. METHODS:PubMed, Embase, and Scopus were searched for studies reporting patient-reported outcomes, metal ion levels, or revision rates for both LDH-THA and HRA. The risk of bias was assessed using the Methodological Index for Non-Randomized Studies score. Random-effects meta-analysis evaluated revision risk; cobalt and chromium levels; University of California, Los Angeles (UCLA) activity; Harris-Hip Scores (HHS); Oxford Hip Scores (OHS); and Western Ontario and McMaster Universities Osteoarthritis Index. RESULTS:Of 221 studies, 21 met inclusion criteria, including 5,545 LDH-THAs and 3,197 HRAs. The unweighted pooled revision rate was 16% for THA and 7.8% for HRA. Meta-analysis showed higher cobalt (standardized mean difference [SMD] 1.07) and chromium (SMD 0.53) levels in THA. Revision risk (odds ratio 1.75), UCLA (-0.44), and HHS (-0.32) favored HRA, though not significantly. CONCLUSION/CONCLUSIONS:Although the usage of large-head MoM THA is largely historic, our findings suggest that MoM hip resurfacing arthroplasty has a more favorable outcomes profile with reduced systemic metal ion exposure, reinforcing its role in younger, active patients, where conventional or large-head THA may fall short. LEVEL OF EVIDENCE/METHODS:Level III, systematic review of Level I, II, and III studies. See Instructions for Authors for a complete description of levels of evidence.