Journal of Arthroplasty最新文献

Introduction: Revision total hip (rTHA) and revision knee arthroplasty (rTKA) burdens continue to increase while overall reimbursement decreases. We sought to evaluate the percentage and variability of the Diagnostic-Related Group (DRG) reimbursement spent on implants in revision arthroplasty.

Methods: A consecutive series of 199 rTHAs and 187 rTKAs performed between June 1, 2019, and June 1, 2021, was reviewed at one academic medical center. Patient characteristics, preoperative diagnosis, implant records, and billing data were recorded for DRG 466 (revision hip or knee arthroplasty with major complication), 467 (revision with complication or comorbidity), and 468 (revision without comorbidity or complication). Data were stratified by DRG and diagnosis. Implant, surgery type, and patient comorbidity factors were analyzed for association with increased costs.

Results: Implant costs comprised an average of 24% of reimbursements for DRG 466 (range, 2.4 to 133), 36.7% for DRG 467 (range, 3.5 to 118), and 35% for DRG 468 (range, 2.5 to 175). When stratified by diagnoses, groups with the largest ranges in implant costs as a percentage of the reimbursement were aseptic loosening (range, 6.6 to 178.2), infection (range, 3.2 to 129.3), and metallosis (range, 2.4 to 108.6%). Implants for rTKA were significantly more of the overall reimbursement than rTHA across all DRGs (33.3 versus 25.7%, P < 0.001). Factors associated with higher implant costs included more prior arthroplasty surgeries on the same joint (P < 0.001) and an American Society of Anesthesiologists (ASA) score ≥ 3 (P = 0.006).

Discussion: A major portion of the DRG reimbursement is spent on implants in revision arthroplasty. However, there is a wide range in cost determinants, making it difficult to determine the profitability associated with individual diagnoses. Our findings highlight the limited ability of the DRG system to capture the complexity and variability of costs in revision total joint arthroplasty.

Background: The two-stage exchange arthroplasty is a preferred treatment for chronic periprosthetic joint infection (PJI). A gap in knowledge remains surrounding the optimal follow-up period for staged revision. This study aimed to determine the length of time PJIs should be monitored after two-stage exchange arthroplasty and the timepoints by which most failures occur.

Methods: This retrospective study evaluated 148 patients who underwent two-stage exchange arthroplasty for chronic total knee arthroplasty (TKA) PJI from 2015 to 2022. Dates of failure were recorded using the 2019 Musculoskeletal Infection Society Outcome Reporting Tool criteria. Bayesian regression with Monte Carlo Markov Chain simulations was used to generate simulation models with one or two statistically significant breakpoints in cumulative failure curves. "Tier 1 failure" included patients on suppressive antibiotics; "Tier 1 plus 2 failure" excluded them, with Tier 3 and 4 cases classified as failures in both models.

Results: For Tier 1 failure, we identified a significant breakpoint at 1.20 years (95% confidence interval [CI]: 1.03 to 1.47), with a 441% greater failure rate before this point (P < 0.001). A two-breakpoint model identified breakpoints at 1.11 and 2.42 years; failure was 3.43 times higher before 1.11 years than between 1.11 and 2.42 years and 7.40 times higher than after 2.42 years (P < 0.001). For Tier 1 plus 2 failure, a single breakpoint at 0.73 years (95% CI: 0.62 to 1.06) was associated with 997% higher failure than before this time (P < 0.001). Single breakpoint models demonstrated superior overall fit.

Conclusion: Failures clustered early, with steep first-year accrual for the Tier 1 plus 2 endpoint, while Tier 1 reoperation failures continued to accumulate into the second year. Breakpoints mark the onset of declining failure rates, rather than complete elimination of risk. Thus, one-year follow-up may be adequate for studies using broad failure definitions, while extended follow-up into the second postoperative year remains essential to fully characterize late failures.

Introduction: The outcome of periprosthetic joint infections (PJIs) is not only contingent on treatment strategy and host factors, but also on the infecting organism. Corynebacterium, a genus of gram-positive bacterium, is uncommonly implicated in PJIs, but represents a challenge when present, as it commonly demonstrates resistance to often-used antibiotics. Given the limited data available, we sought to report on our institution's historical experience with managing PJI of the hip or knee due to Corynebacterium.

Methods: A retrospective review was conducted of all total hip and knee arthroplasties performed at our institution from 2016 to 2023 for PJI in which the Corynebacterium genus was identified. Demographic, surgical, and clinical outcomes data were collected. Overall, 18 patients were identified who had a mean age of 65 years, and there was a predominance of women (94.4%). Patients, on average, had 4.9 prior surgeries.

Results: Surgical treatment of the Corynebacterium PJI included single-stage revision (n = five), irrigation and debridement (n = two), resection arthroplasty (n = one), and two-stage revision (n = 10). Overall, five cases (27.8%) were polymicrobial infections. Most cases received multiagent treatment (61.1%) administered in a concurrent (90.9%) fashion. The average antibiotic duration was 6.5 weeks. The majority (57.9%) of patients had a prior PJI, and all but one, for which data were unavailable, were infected with a multidrug-resistant strain of Corynebacterium. In total, 13 patients had tetracycline-resistant strains of Corynebacterium, and no cases demonstrated vancomycin resistance. At final follow-up (mean = 2.9 years, standard deviation = 2.8), 16 patients had never undergone amputation, 15 had no reinfection, and 12 patients were alive.

Conclusion: Corynebacterium-associated PJIs represent a unique subset of disease that can be challenging to manage, in part due to its antibiotic resistance profile. However, with close collaboration between surgical and infectious disease teams, reasonable outcomes can be expected.

Background: Venous thromboembolism (VTE) is a serious complication following total knee arthroplasty (TKA). While a history of prior VTE is a recognized risk factor for subsequent events, the impact of its timing relative to surgery on postoperative outcomes is unclear. This study examined the association between prior VTE timing and postoperative deep vein thrombosis (DVT), pulmonary embolism (PE), readmission, and periprosthetic joint infection (PJI) following TKA.

Methods: A retrospective cohort study using a large national database identified patients who underwent primary TKA using Current Procedural Terminology (CPT) codes. Patients who had a prior VTE were stratified by interval from VTE to TKA (zero to three, three to six, six to 12, 12 to 18, 18 to 24 months, then yearly up to five years). Propensity score matching (PSM) (1:1) controlled for demographics and comorbidities, resulting in 22,447 patients who had a prior VTE compared to matched controls. Outcomes included 90-day postoperative DVT, PE, hospital readmissions, and 2-year PJI. Statistical analyses used Chi-square and Welch's t-tests.

Results: Patients who had a prior VTE had higher 90-day DVT after TKA (13.2 versus 1.5%; odds ratio (OR) 10.0 [8.9 to 11.2]) and higher 90-day PE (1.8 versus 0.2%; OR 9.2 [6.7 to 12.5]). The odds of developing VTE postoperatively increased as the VTE-to-surgery interval shortened, with the highest rates in patients who had a recent (zero to three months) VTE. Prior VTE was associated with increased 2-year PJI risk (2.4 versus 1.8%; OR [odds ratio] 1.3 [1.2 to 1.5]).

Conclusion: Prior VTE significantly increased the risk of 90-day DVT, PE, and 2-year PJI after TKA. Patients who had a recent VTE may warrant enhanced perioperative surveillance, individualized thromboprophylaxis, and heightened infection risk awareness.

Background: The Kellgren-Lawrence (KL) grading system is the standard for assessing knee osteoarthritis (OA) severity. However, it is limited by major observer variability. Artificial intelligence (AI) may standardize grading, yet external validation is limited. This study evaluated the diagnostic efficacy of AI-based software on a large, independent, multicenter clinical dataset.

Methods: This multicenter, retrospective, pivotal study included 2,546 knee radiographs from 1,273 patients across two tertiary hospitals in Korea. A reference standard was established by an expert consensus panel, with KL grades 0 and 1 consolidated into a single KL ≤ 1 category. The AI software was trained exclusively on public United States datasets (Osteoarthritis Initiative and the Multicenter Osteoarthritis Study) and validated on this separate Korean dataset. The primary outcomes were grade-specific sensitivity and specificity for four categories (≤ 1, 2, 3, and 4). The secondary outcomes included accuracy, the area under the receiver operating characteristics curve (AUC), and binary diagnostic performance for radiographic OA (KL ≥ 2).

Results: The AI met all pre-specified non-inferiority endpoints. For KL ≤1, sensitivity was 90.5% (95% confidence interval (CI), 87.9 to 92.8) and specificity was 96.6% (95% CI, 95.0 to 97.9). For KL grade 4, sensitivity was 97.7% (95% CI, 97.5 to 99.1), and specificity was 98.4% (95% CI, 97.5 to 99.1). For KL grade 2, sensitivity was 77.2% and specificity was 95.3%. In the binary classification of radiographic OA, the AI achieved an AUC of 0.94 (95% CI, 0.92 to 0.96), sensitivity of 96.6%, specificity of 90.5%, and accuracy of 94.2%.

Conclusion: In a large-scale, multicenter external validation using a dataset entirely independent of its training data, the AI-based software demonstrated high and robust diagnostic performance for KL grading. These findings support the software's potential for clinical integration to improve the consistency, objectivity, and efficiency of knee OA severity assessment.

Background: Emerging evidence suggests revision for early aseptic loosening following total knee arthroplasty (TKA) is associated with both short, native tibial stem (TS) design and morbid obesity (body mass index ≥ 40). The use of short, fully cemented stem extensions has been suggested to mitigate this risk.

Methods: A retrospective review was performed of patients undergoing primary TKA at a single large academic center between August 2015 and December 2022. Cohorts were created based on the presence (stemmed tibia (ST)) or absence (non-stemmed tibia (NST)) of a fully cemented short TS extension. Cox proportional hazards models were used to assess implant survival across all follow-up periods. A total of 3,930 patients were included (NST = 3,757, ST = 173). The mean time to final follow-up was 5.8 years for the NST cohort and 4.6 years for the ST cohort (P < 0.001).

Results: All-cause revision occurred in 0.98% (n = 37) of the NST cohort at a mean time of 25 months. There was one revision (0.58%) in the ST cohort. Aseptic loosening occurred in two patients (0.05%), both in the NST cohort, at an average of 65 months. Morbid obesity (hazard ratio (HR) = 4.04, 95% confidence interval (CI): 1.75 to 8.60), age (HR = 0.96, 95% CI: 0.92 to 0.99), and being a man (HR = 2.05, 95% CI: 1.08 to 3.97) were significant predictors of all-cause revision, while tibial stem extension (HR = 0.56, 95% CI: 0.06 to 2.20) was not.

Conclusion: This study did not find short, native TS design to be associated with early tibial aseptic loosening nor increased all-cause revision following primary TKA. Morbid obesity, younger age, and being a man were associated with greater risk of revision, regardless of stem extension at five years.

Introduction: Randomized controlled trials (RCTs) remain the gold standard for evaluating the efficacy and safety of novel interventions. This systematic review assessed the current quality of hip and knee arthroplasty RCTs using a modified Jadad scale, along with other key metrics, including trial registration and conduct of power analyses.

Methods: PubMed was queried in May 2024 to identify hip and knee arthroplasty RCTs published from 2014 through 2023 in four leading orthopaedic journals. Each RCT was scored using a modified Jadad scale, which assesses randomization, blinding, and participant withdrawal, categorizing studies into low, moderate, or high quality. Chi-square analyses were used to assess associations between article characteristics.

Results: Of 566 RCTs, 47.5% were graded as high quality, 39.8% as moderate quality, and 12.7% as low quality according to the modified Jadad scale, largely due to a lack of double blinding. Low or moderate quality was more common in RCTs that reported industry funding (relative risk [RR], 1.27; 95% confidence interval [CI], 1.08 to 1.49; P = 0.006) or those focused on surgical technology (RR, 1.65; 95% CI, 1.42 to 1.90; P < 0.001). Trial registration was not reported in 41.2% of articles, funding statements were not identified in 22.3% of RCTs, and a priori power analyses were not conducted in 16.3% of RCTs. Of the 474 RCTs that did conduct a power analysis, 130 (27.4%) did not retain enough patients to meet sufficient statistical power per their power analyses. Among these 130 studies, 77 (59.2%) did not identify any statistically significant difference between groups.

Conclusion: More than half of recent hip and knee arthroplasty RCTs were of low to moderate quality, with notable deficiencies in blinding, trial registration, and power analyses. Continued efforts to improve methodological rigor and transparency are essential to advance the quality and credibility of arthroplasty research.

Background: Total knee arthroplasty (TKA) performed for post-traumatic osteoarthritis (PTOA) is associated with higher complication and revision rates than TKA for primary osteoarthritis (OA). This study aimed to compare implant survival and identify risk factors for revision in TKA performed for PTOA versus OA using registry data.

Methods: The TKA procedures from 2012 to 2022 in the German Arthroplasty Register (EPRD) were analyzed (n = 289,382). The incidence of PTOA was 2.4% (n = 6,982). Implants were categorized as unconstrained or constrained (varus-valgus stabilized or hinge). Kaplan-Meier survival analysis and multivariable Cox proportional hazards models were used to assess implant survival, adjusted revision risk, and independent risk factors for revision.

Results: A total of 10,341 complications were recorded, with PTOA showing a higher complication rate than OA (5.7 versus 3.5%; P < 0.001). Aseptic revision rates were higher for unconstrained TKA in PTOA (P < 0.001), but not for constrained TKA (P = 0.1), whereas septic revision rates were higher for PTOA with both implant designs (both P < 0.001). The most common reasons for revision were infection (19%) and instability (8%). After adjustment for age, sex, body mass index, weighted Elixhauser score, fixation method, patellar resurfacing, and hospital case volume, a 45% higher risk of revision was observed after TKA for PTOA compared with OA. For unconstrained TKA in PTOA, the revision risk was 36% higher compared with OA (hazard ratio = 1.36; P < 0.001). Independent risk factors for revision in unconstrained TKA for PTOA included hospital volumes ≤ 200 annual cases and TKA without patellar resurfacing.

Conclusion: An increased adjusted risk of revision was observed after TKA for PTOA compared with OA. While aseptic revision rates varied by implant constraint, septic revision rates were higher in PTOA independent of constraint. Lower hospital volume and the absence of patellar resurfacing in unconstrained implants further increased revision risk, whereas higher implant constraint was protective regarding the risk of aseptic revision.

Background: As implants in primary total hip arthroplasty (THA) continue to evolve, surgeons may elect to combine femoral and acetabular components from different manufacturers. However, the prevalence of mixing implants in contemporary hip arthroplasty is unknown, as is the consequence that this may or may not have on implant survival.

Methods: A nationwide registry was used to select patients 65 years or older who underwent primary THA between 2012 and 2021 and who had a minimum 2-year follow-up to create a retrospective cohort comparison of patients who had matched versus mixed manufacturer components. A total of 434,985 cases were identified [matched: 413,607 (95%), mixed: 21,378 (5%)]. The unadjusted and adjusted risk of all-cause revision, as well as revision for aseptic loosening, infection, instability, and periprosthetic fracture, were modeled with cause-specific Cox models.

Results: Mixing THA components increased over time from less than 2% of cases in 2012 to nearly 17% in 2021 (P < 0.001). The mixed cohort more commonly utilized dual mobility bearings (27%, 4,956 versus 7%, 24,631; P < 0.001) and triple-tapered femoral stem designs (18%, 7,185 versus 9%, 27,987; P < 0.001). After controlling for potential confounding variables, there was no difference between the two groups in terms of all-cause revision (hazard ratio (HR) 1.0, 95% confidence interval (CI) 0.9 to 1.1), revision for aseptic loosening (HR 1.2, 95% CI 0.9 to 1.6), revision for infection (HR 1.2, 95% CI 0.9 to 1.4), revision for instability (HR 1.0, 95% CI 0.8 to 1.2), or revision for periprosthetic fracture (HR 0.9, 95% CI 0.7 to 1.2). There was no difference in revision-free survival time between groups.

Conclusion: Mixing implants from different manufacturers in primary THA does not result in an associated difference in the risk of early revision between mixed versus matched manufacturer components.

Background: The time spent providing postoperative care for total hip arthroplasty (THA) and total knee arthroplasty (TKA) has increased provider workload, drawing attention to the Relative Value Scale Update Committee's (RUC) current estimation of work Relative Value Units (wRVUs). Our aim for this study was to quantify the postoperative work performed by the surgeon and their team for THA and TKA during the 90-day global period. We hypothesized that the work intensity and time spent on postoperative communication were higher than estimated by current wRVUs.

Methods: We retrospectively evaluated all patients undergoing primary total joint arthroplasty (TJA) at our institution between January 1, 2019, and December 31, 2024. Primary outcomes included the number of postoperative interactions from discharge to 90 days after surgery. These included office visits, telehealth visits, phone calls, and patient portal messages.

Results: From 2019 to 2024, the average number of postoperative TJA interactions per patient increased across all modalities. Telephone encounters spiked during the COVID-19 pandemic and remain elevated, while portal messages rose more than fivefold. Office visits averaged 2.3 per patient, exceeding the two currently recognized in RUC valuations. Administrative tasks and telehealth also showed steady annual growth. Meanwhile, hospital lengths of stay decreased from 44.5 hours in 2018 to 32.6 hours in 2022. These findings highlight a shift of postoperative care from institutional settings to surgeon offices and virtual platforms.

Conclusion: Over the past five years, postoperative care for THA and TKA has increasingly relied on surgeon teams, resulting in a measurable rise in office visits, virtual encounters, and administrative messaging not reflected in current RUC valuations. With declining physician reimbursement, these findings underscore the need to update valuation models to capture the true scope of postoperative care in current joint arthroplasty practice.