Journal of Arthroplasty最新文献

Background: While testosterone replacement therapy (TRT) is known to affect cardiovascular physiology, its impact on outcomes following total hip arthroplasty (THA) remains unclear. This study aimed to assess whether preoperative TRT use is associated with increased complications following THA.

Methods: A retrospective cohort study using a large national database was performed. Adult patients undergoing primary THA before February 2020 with 5-year follow-up were stratified based on preoperative TRT use within one year of surgery. Patients who had a history of septic arthritis, osteonecrosis, or pathologic fractures were excluded. Propensity score matching (1:1) was used to balance cohorts. Outcomes included medical complications at 90 days and one year and prosthetic complications up to five years postoperatively. Following matching, 3,953 patients were included in each cohort.

Results: At 90 days, TRT use was associated with higher rates of deep vein thrombosis (2.8 versus 2.0%; P = 0.023), pneumonia (3.2 versus 1.7%; P < 0.001), and sepsis (4.2 versus 0.9%; P < 0.001). At one year, TRT users had increased rates of deep vein thrombosis (4.3 versus 3.0%; P = 0.002), cardiac events (2.9 versus 1.7%; P < 0.001), pneumonia (6.1 versus 3.4%; P < 0.001), acute kidney injury (7.6 versus 5.6%; P < 0.001), and sepsis (3.8 versus 1.9%; P < 0.001). At five years, TRT users had higher rates of periprosthetic joint infection (3.1 versus 1.6%; P < 0.001), periprosthetic fracture (2.4 versus 1.4%; P = 0.003), loosening (1.7 versus 1.0%; P = 0.007), prosthetic dislocation (2.5 versus 1.2%; P < 0.001), and revision surgery (4.1 versus 2.3%; P < 0.001).

Conclusions: Preoperative TRT use was associated with increased risk of medical and prosthetic-related complications following THA.

Background: Periprosthetic joint infection (PJI) remains one of the most devastating complications following total joint arthroplasty. While platelets are recognized for their role in hemostasis, growing evidence suggests they also serve as immune effectors. Experimental data support a link between platelet depletion and infection risk, yet clinical evidence is limited.

Methods: We performed a retrospective cohort study using a large national database to identify patients undergoing primary total knee arthroplasty between 2015 and 2023. Patients were stratified by preoperative platelet count: ≤ 50,000/μL, 50,000 to 99,000/μL, 100,000 to 149,000/μL, and ≥ 150,000/μL. The primary endpoint was PJI within one year, and the secondary endpoint was superficial surgical site infection (SSI). Multivariable logistic regressions and propensity score matching were used to adjust for demographics and comorbidities. Of 182,043 patients included in the study, 8,380 (4.6%) had platelet counts less than 150,000/μL.

Results: In adjusted models, risk of PJI increased stepwise with lower platelet counts: odds ratio (OR) 1.42 (95% confidence interval [CI]: 1.15 to 1.73) for 100,000 to 149,000/μL, OR 3.67 (95% CI: 2.57 to 5.10) for 50,000 to 99,000/μL, and OR 5.12 (95% CI: 1.73 to 12.19) for ≤ 50,000/μL compared with ≥150,000/μL (P-value trend < 0.001). Platelet count was not significantly associated with SSI at any threshold in all models.

Conclusions: Preoperative thrombocytopenia is strongly and progressively associated with increased risk of PJI, but not SSI, after total knee arthroplasty. These results highlight the role of platelets as immune effectors in the periprosthetic space and suggest platelet count and function as underrecognized, potentially modifiable risk factors for arthroplasty infection. Prospective studies are needed to determine whether optimization of platelet levels can reduce PJI risk.

Level of evidence: III.

Background: Although robotic arm-assisted total hip arthroplasty (RA-THA) has been increasing in popularity, the outcomes following its use are still uncertain.

Methods: We performed a propensity-matched prospective cohort study comparing all-cause revision, odds of instability/dislocation, odds of periprosthetic joint infection (PJI), and hospital length of stay (HLOS) between patients receiving an RA-THA versus a conventional total hip arthroplasty (CO-THA). Consecutive patients undergoing a primary elective total hip arthroplasty (THA) via a posterior approach at our institution between January 2019 and February 2024 were included. Those who received a bilateral simultaneous THA were excluded. We successfully matched 268 pairs of hips.

Results: There was no difference in all-cause revision risk between the RA-THA and CO-THA groups (hazard ratio = 1.00, P = 1.000). Furthermore, there was also no significant difference in the odds of instability/dislocation (odds ratio = 1.00, P = 1.000) and the odds of PJI (odds ratio = 0.75, P = 0.704. The HLOS was significantly shorter in the RA-THA cohort by 0.49 days (P = 0.044). The median follow-up duration was 3.46 years (interquartile range: 1.92 to 4.64).

Conclusion: Although there was no difference in short-term revision risk in patients receiving an RA-THA versus a CO-THA, likely, the benefits from improved implant positioning are yet to be realized. This study is underpowered, and results should be interpreted with caution. The shorter HLOS observed in the RA-THA group may help offset the increase in consumable costs incurred. Further studies with long-term follow-up, alongside a cost-effectiveness analysis, are required.

Background: Indications for curved intertrochanteric varus osteotomy (CVO) for osteonecrosis of the femoral head (ONFH) with a beak-shaped healthy area (BHA) remain unclear. This study aimed to evaluate the clinical outcomes and radiographic findings of CVO for ONFH with BHA.

Methods: This comparative study included 77 patients who were Japanese Investigation Committee type B and C1 ONFH. From January 2005 to December 2022, 21 patients (22 hips) who had a BHA underwent CVO (BHA group), whereas 56 patients (62 hips) who did not have a BHA underwent CVO (control group). The average follow-up period was 98.4 and 97.2 months in the BHA and control groups, respectively. Clinical and radiographic evaluations included the Harris Hip Score, complication rates, radiographic parameters, and survival rates. Endpoints were defined as conversion to total hip arthroplasty or radiographic failure.

Results: The preoperative and postoperative Harris Hip Score values were similar between the BHA and control groups. The complication rates were comparable between the groups. The postoperative intact ratio and varus angle showed no significant differences. In the BHA group, three cases of beak fractures occurred within the first year postoperatively. The 8-year survival rate based on conversion to total hip arthroplasty and radiographic failure did not differ significantly between the groups.

Conclusions: The clinical outcomes of CVO for ONFH with BHA were comparable to those of CVO for ONFH without BHA, indicating that CVO may be a viable joint-preserving option even in cases presenting with BHA.

Background: Surgeons use cementless unicompartmental knee arthroplasty (UKA) as a joint-preserving alternative to total knee arthroplasty. However, cementless UKA survivorship and revision data remain fragmented. To address this gap, we systematically reviewed (1) survivorship of cementless UKAs reported at time points ≤ five years and ≥ 10 years and (2) the revision indications across implant types.

Methods: The PubMed and EMBASE databases were searched to identify relevant studies. Inclusion criteria comprised cementless UKA devices with available survivorship and revision data. Study quality was assessed using the modified Coleman Methodology Score and the Journal of Bone and Joint Surgery Level of Evidence criteria.

Results: We identified 27 studies on seven cementless device designs. Medial UKAs accounted for most implants (81.5%). Studies with 5-year time points or less reported a median survivorship of 96.1%. At time points ≥ 10 years, survivorship decreased to 92.0% (P = 0.01). The most frequent revision indications included instability (16%), progression of osteoarthritis (14%), and aseptic loosening (11%). In some cases, the indications for revision depended on the device: one device was associated with polyethylene-related complications (57%), while a blade-anchored device was frequently revised following loosening (63%).

Conclusions: Success was device specific, with three of four cementless UKA devices exceeding 95% survivorship within five years and three of five achieving at least 92% survivorship after 10 years. It remains unclear whether cementless UKA devices can decrease revision rates comparable to total knee arthroplasty, promoting increased utilization.

Background: Evaluation and management of bone loss in revision total knee arthroplasty (rTKA) poses a demanding challenge. The rising number of knee revisions and rerevisions has led to increasing bone loss severity, and previous bone loss classification systems fail to provide adequate assessment of the diaphysis. The Scuderi classification was recently introduced to better assess diaphyseal bone loss and underwent internal validation. The purpose of this study was to perform an external validation using preoperative radiographs of failed stemmed rTKA and describe the interobserver and intraobserver reliability.

Methods: From our institutional database, 128 preoperative radiographs of failed rTKAs with stemmed prostheses awaiting rerevision were identified. There were 120 stemmed femoral prostheses (60 cemented, 60 hybrid fixation) and 120 stemmed tibial prostheses (60 cemented, 60 hybrid fixation) that were subject to analysis. There were two readers who had similar experience levels who scored the cases according to the Scuderi classification, and each reader performed two independent reads at least two weeks apart from the first read. The levels of interobserver and intraobserver reliability were determined by the intraclass correlation coefficients.

Results: Strong intraclass correlation coefficient for both femur (total: 0.96) and tibia (total: 0.89) has been demonstrated among the graders. Intraobserver reliability of 0.86 (grader 1) and 0.79 (grader two) for femur and 0.8 (grader 1) and 0.71 (grader 2) for tibia demonstrated satisfactory agreement. Absolute score congruency between the readers was 86.7% for the femur and 89.2% for the tibia, showing excellent grading reproducibility for this new classification.

Conclusions: This study provided an external validation of this bone loss classification in revision prosthesis with strong to near-perfect interobserver and intraobserver reliability. Based on our reported results, we advocate the use of this intuitive grading scheme, which can facilitate bone loss evaluation and may provide a future foundation to assist with implant selection in these complex cases.

Background: Recurrent instability continues to challenge arthroplasty surgeons, and constrained liners may be utilized for cases of recurrent or multidirectional instability following revision total hip arthroplasty (rTHA). The purpose of this study was to evaluate dislocation rates and survivorship after rTHA using constrained liner (CL) prostheses.

Methods: Patients who underwent rTHA using a CL prosthesis were retrospectively reviewed from January 1, 2013, to December 31, 2024. Patients who had antibiotic spacers or megaprostheses, or those who had less than one year of follow-up, were excluded. Survivorship analyses were performed to determine dislocation and reoperation-free survivorship through follow-up. A total of 98 rTHAs with CL were included, with a mean follow-up time of 3.9 years (range, one to 10.8).

Results: The CL dislocation rate at final follow-up was 16.3% (16 of 98), and the 9-year dislocation-free survivorship was 71% (95% confidence interval [57 to 89]). There was neither statistically significant difference in 9-year dislocation-free survivorship among CL systems (P = 0.73), CLs inserted into cups that were retained versus revised (P = 0.95), nor CLs that were snapped in versus cemented (P = 0.38). The overall reoperation rate at final follow-up was 49.0% (48 of 98), and the 9-year all-cause reoperation-free survivorship was 33% (95% confidence interval [17 to 62%]). Of those 48 requiring reoperation, 27 (56.2%) were for infection and 14 (29.2%) were for recurrent hip instability. There was neither statistically significant difference in 9-year all-cause reoperation-free survivorship among CLs inserted into cups that were retained versus revised (P = 0.67) nor CLs that were snapped in versus cemented (P = 0.34).

Conclusions: In a cohort where a majority of patients had multiple prior rTHAs secondary to hip instability, CLs were a salvage option for preventing repeat dislocation; however, dislocation and reoperation rates remain high.

Level of evidence: Level III Evidence, Retrospective Cohort Study.

Background: Metaphyseal bone loss represents a major challenge in revision total knee arthroplasty (RTKA). Highly porous metaphyseal cones have potential for osseointegration and durable fixation. While early evidence was limited to tantalum cones, newer designs, such as three-dimensional-printed titanium cones, have been introduced by multiple manufacturers, necessitating an updated synthesis of the literature.

Methods: PubMed, Scopus, and Cochrane databases were searched from inception through October 1, 2024. Eligible studies included randomized controlled trials and observational cohorts reporting clinical or radiological outcomes of metaphyseal cones in RTKA with a minimum 1-year follow-up. Demographics, implant characteristics, functional scores, survivorship, cone removal rates, and radiographic outcomes were recorded. Pooled analyses were performed using random-effects models, with subgroup analyses by cone material and fixation type. There were 63 studies comprising 4,433 patients and 5,435 cones that were included, with 79.9% of femora and 75.4% of tibiae involving Anderson Orthopedic Research Institute type 2B or 3 defects.

Results: Significant improvements in function were observed, with pooled Knee Society Score Knee and Function scores of 77.4 (95% confidence interval [CI], 70.6 to 84.3) and 67.5 (95% CI, 58.4 to 76.6), respectively. The pooled all-cause re-revision rate at a weighted mean follow-up of 49.7 months was 13.5% (95% CI, 11.0 to 16.2), most commonly due to infection, whereas cone removal occurred in 3.6% (95% CI, 2.2 to 5.2), with aseptic loosening accounting for only 0.7%. Radiographic osseointegration was achieved in 96.0% (95% CI, 92.5 to 98.5). Subgroup analyses demonstrated no significant difference in survivorship between tantalum versus titanium cones (3.7 versus 2.2%, P = 0.199) and cemented versus hybrid fixation (4.7 versus 1.9%, P = 0.274).

Conclusions: Modern metaphyseal cones have high osseointegration rates and implant survivorship in RTKA, with comparable outcomes noted across different cone materials and fixation strategies. Failure due to aseptic loosening is exceedingly rare, with infection being the predominant cause of cone revision.

Background: Distal femoral replacement (DFR) is a common limb salvage option for bone tumors. Postoperative outcomes partly depend on the integrity of the extensor mechanism, yet patellar height and joint line position have not been well studied in oncologic reconstructions.

Methods: We retrospectively reviewed 86 patients who underwent modular DFR with rotating hinge prostheses (1992 to 2024). Demographics, surgical parameters, and functional outcomes were collected, including knee flexion, extensor lag, and Musculoskeletal Tumor Society (MSTS) scores. Postoperative patellar height was assessed with the Insall-Salvati ratio (ISR) and Blackburne-Peel index (BPI). Joint line position was measured relative to the fibular head. Statistical analyses included linear, multivariable, and segmented regression.

Results: The mean ISR was 0.99 ± 0.22, BPI 0.78 ± 0.20, and joint line height was 17.7 ± 6.1 mm. Patellar height was classified as baja (14.0%), pseudobaja (18.6%), normal (59.3%), and alta (8.1%). Higher ISR correlated with greater knee flexion up to 120° (P < 0.001), after which the effect plateaued. BPI was associated with increased knee flexion (P < 0.001) and MSTS score (P = 0.005). A higher number of prior surgeries predicted lower BPI (P = 0.009). Patients who had patella baja demonstrated significantly reduced flexion, higher extensor lag, and inferior MSTS scores compared with other groups (P < 0.05). Joint line position itself was not associated with differences in functional outcomes, although longer resection length and prior radiotherapy were linked to joint line elevation.

Conclusions: Increased patellar height was associated with superior functional outcomes following DFR, while patella baja and pseudobaja were linked to poorer knee motion arc and functional scores. Multiple prior surgeries were associated with decreased patellar height. Careful restoration of the joint line to its proper position, along with prevention of patella baja, may improve outcomes in patients undergoing DFR.

Background: Understanding implant price trends is critical amid growing demand for total joint arthroplasty (TJA) and increasing cost containment pressures. Previous studies have documented trends in costs, reimbursements, and volume for TJA. However, the relationship between implant prices, hospital and physician reimbursement, and patient financial burden remains poorly defined. This study evaluated inflation-adjusted implant pricing trends in TJA and their alignment with physician and hospital reimbursement and patient out-of-pocket (OOP) costs.

Methods: Implant prices for primary total knee arthroplasty (TKA), total hip arthroplasty (THA), revision TKA (rTKA), and revision THA (rTHA) from 2009 to 2021 were obtained from a large publicly available implant registry. Cost, reimbursement, and patient OOP spending data were sourced from a commercial insurance claims database. There were 629,651 total procedures analyzed. All costs, reimbursements, and prices were adjusted for inflation. Trends were analyzed using linear regressions.

Results: The average price for TKA implants was $5,899, $6,776 for THA, $11,576 for rTKA, and $7,419 for rTHA. Between 2009 and 2021, implant prices declined markedly for TKA (-38%), THA (-37%), and rTHA (-28%) and remained stable for rTKA (+8%). Overall costs and hospital reimbursement remained stable or modestly decreased, whereas physician reimbursement declined markedly across all procedures (-26 to -32%). Patient OOP spending remained relatively unchanged across all procedures.

Conclusions: Although implant prices have decreased over time, the financial benefit has not been realized by patients or surgeons. To our knowledge, this is the first study contextualizing implant cost trends alongside total costs, reimbursement, and OOP patient costs in TJA, and it highlights persistent gaps in cost transparency. In an era of increasing TJA volumes and mounting cost control pressures, these findings underscore the need for surgeon awareness of implant costs, which is particularly relevant in implementing future changes to clinical practice, payment, and policies.