Journal of Arthroplasty最新文献

Background: The prosthetic design landscape for total knee arthroplasty (TKA) is extensive. Modified surface geometries aim to replicate native kinematics for superior outcomes, yet evidence remains conflicting regarding optimal design efficacy based on patient-reported and objective metrics. The primary aim of this study was to compare the patient satisfaction between UC (ultra- congruent) and CR (cruciate- retaining) insert designs in bilateral simultaneous TKA, and the secondary aim was to study the parameters validating potential reasons behind any differences in the outcomes between these two design philosophies.

Methods: In this Institutional Review Board (IRB)-approved, prospective, randomized, double-blinded (patient/assessor), Level I trial, 53 patients (mean age 63 years [range, 54.8 to 66.6] and 45 women). Patients had bilateral end-stage osteoarthritis underwent bilateral simultaneous TKA by a single surgeon. Each patient received a randomly assigned UC insert in one knee and the contralateral knee received a CR insert. The primary outcome was the Forgotten Joint Score (FJS). The secondary outcomes included clinical and radiological parameters, including Oxford Knee Score (OKS), Knee Society Score (KSS), and gait analysis. Patients were assessed preoperatively and at three, 12, and 24 months postoperatively. Intraoperative static stability and post-operative (six months) dynamic stability was assessed.

Results: The UC group demonstrated significantly superior FJS at all postoperative intervals (P < 0.05), with the largest difference at one year (UC: 73.2 ± 6.0 versus CR: 67.5 ± 16.6; P = 0.007). There were no statistically significant differences found in other parameters at any time point between the two groups.

Conclusion: The UC inserts provide significantly better patient-reported joint awareness (FJS) compared to CR inserts at 2-year follow-up in bilateral simultaneous TKA. This subjective advantage was not validated by differences in objective parameters. The UC design represents a viable Posterior Cruciate Ligament (PCL) sacrificing alternative with enhanced patient-perceived outcomes.

Background: The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) is a composite patient-reported outcome measure intended to represent overall knee health. Limited investigations exist to determine the validity of KOOS JR as a marker of joint function among total knee arthroplasty (TKA) patients. The goal of this study was to evaluate the underlying construct of KOOS JR.

Methods: Data were collected from 156 patients (94 women; mean age 68 years (range, 39 to 83)) who were scheduled to undergo primary elective TKA. The KOOS JR and eight physical performance measures (PPMs) were postoperatively administered at two, six, and 12 weeks. Spearman's rank correlation coefficients (rho) were used to assess the association among our variables. Principal component analyses (PCAs) were performed to determine the relative contribution of each KOOS JR domain score (i.e., stiffness, pain, and function) to the total score.

Results: The KOOS JR total score showed the strongest correlation (P < 0.001) with the pain score (rho = 0.94 to 0.96), followed by the function (rho = 0.80 to 0.85) and stiffness (rho = 0.59 to 0.65) scores. The PCA indicated that one dominant component explained 69 to 74% of the total variance across the three domain scores, with the pain score contributing the most. There were no PPMs that were correlated with the KOOS JR function score (P ≥ 0.059), except the Step Up measure that was weakly correlated at six weeks (rho = -0.33, P = 0.003).

Conclusions: The KOOS JR appears to be a unidimensional construct that largely reflects perceived pain, despite its intention to represent overall knee health. Appropriate outcome metrics should be selected based on the specific goals of assessment and tailored to reflect what matters most to patients, whether that is reducing pain, addressing stiffness, or achieving functional recovery.

Background: Intramedullary arthrodesis is a common limb-salvage strategy for patients who have recurrent periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). While various constructs have been utilized, outcomes have not been systematically compared. The purpose of this study was to evaluate the modes of failure, functional outcomes, and perioperative complications associated with intramedullary arthrodesis following septic TKA failure.

Methods: A systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. PubMed, Scopus, and Cochrane databases were queried from inception to May 2025. Studies were included if they reported outcomes of intramedullary arthrodesis performed for PJI after TKA with a minimum 90-day follow-up. Construct types, complications, functional outcomes, fusion rates, and revision rates were recorded. Meta-analyses were performed using random-effects models. In total, 55 cohorts comprising 969 knees were included.

Results: The pooled aseptic failure rate was 6%, the reoperation rate was 4%, and the amputation rate was 2%. Overall complication rate was 28%, with recurrent infection being the most frequent (11%). There was a low rate of non-ambulatory patients (4%). Traditional bony fusion constructs had a significantly higher failure rate compared to intercalary prosthetic (12 versus 2%) and cement constructs (12 versus 0%). There was no difference in failure rates between cemented and cementless intramedullary components.

Conclusion: Intramedullary arthrodesis is an effective limb-salvage procedure for failed, infected TKA, achieving low failure rates and acceptable functional outcomes. However, complication rates remain considerably high, and patients should be counselled about these risks. Compared to traditional bone-on-bone fusion, modern prosthetic and intercalary cement constructs conferred lower failure rates. These findings support construct selection as a critical factor in optimizing outcomes for this high-risk population.

Background: Cancer prevalence has largely risen as better survivorship has allowed more patients to live into older adulthood. Total knee arthroplasty (TKA) is a widely performed and increasingly common procedure for end-stage arthritis, and while 90-day outcomes in cancer patients have been described, little is known about outcomes beyond five years. Given the known effects of cancer on bone structure and immunity, this study evaluated implant survival and functional outcomes at five years post-TKA in patients who had cancer compared with a matched cancer-free cohort.

Methods: A retrospective cohort analysis was conducted with a large national database. All adult patients undergoing TKA between July 2002 and July 2020 were identified and grouped by cancer history at the time of surgery. Cohorts were propensity score-matched 1:1 to mitigate differences in baseline demographics and comorbidities. The database identified 134,358 total patients undergoing TKA, of whom 8,937 had a current or previous diagnosis of cancer. After matching, each cohort consisted of 8,709 patients. The primary outcomes at five years included periprosthetic fracture, infection, aseptic loosening, instability, osteolysis, polyethylene wear, myositis ossificans, postoperative pain due to implant, fibrosis due to implant, heterotopic ossification, stiffness, and other instability. Odds ratios (OR) with 95% confidence intervals (CI) were calculated.

Results: At five years, patients who had cancer had significantly higher odds of infection due to prosthesis (2.60 versus 2.10%; OR 1.22, 95% CI: 1.00 to 1.48), aseptic loosening (1.10 versus 0.80%; OR 1.36, 95% CI: 1.00 to 1.83), and stiffness (5.00 versus 3.30%; OR 1.56, 95% CI: 1.34 to 1.81). There were no significant differences observed for other complications.

Conclusion: A history of cancer was associated with increased five-year risk of periprosthetic infection, aseptic loosening, and stiffness after TKA. These findings highlight the need for tailored perioperative optimization, infection prophylaxis, and structured long-term surveillance in this high-risk population.

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.