Journal of Arthroplasty最新文献

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.

Background: Patellar resurfacing in total knee arthroplasty (TKA) is a highly debated topic, with equivocal results. While past literature has investigated pain, functional outcomes, and the cost of resurfaced versus unresurfaced patellae, examining opioid consumption is critical in the wake of the opioid epidemic. We sought to compare postoperative opioid consumption in patients who did and did not undergo patellar resurfacing in primary TKA.

Methods: This was a retrospective review of primary TKAs between 2018 and 2022 performed at a single high-volume institution with arthroplasty surgeons who practiced either selective or universal patellar resurfacing. Preoperative sunrise radiographs were reviewed to assess the severity of patellofemoral arthritis using the Iwano classification. Opioid prescription data were obtained from the Prescription Drug Monitoring Program and converted to morphine milligram equivalents (MMEs). Primary outcomes included total MME consumption and prescriptions filled. Secondary outcomes included length of stay, readmission, and patient-reported outcome measures. Of the 982 knees included, 447 were unresurfaced and 535 were resurfaced. There was a greater proportion of men in the unresurfaced versus the resurfaced group (52.8 versus 33.1%; P < 0.001); however, there was no difference in age (67.2 versus 67.7; P = 0.431).

Results: For the first 30 days postoperatively, the resurfaced group had a greater average MME consumption than the unresurfaced group (705 versus 551 MME, respectively [P < 0.001]). The resurfaced group also filled more prescriptions during this period (2.56 versus 2.09 [P < 0.001]). The percentage of patients who met the minimal clinically important difference (MCID) for the Knee Osteoarthritis and Outcome Score for Joint Replacement was equivalent.

Conclusions: Patients who had resurfaced patellae had a greater opioid consumption in the first 30 days postoperatively compared to those who had unresurfaced patellae. Surgeons should be cognizant that patellar resurfacing in the setting of limited patellar arthritis may influence postoperative opioid consumption.

Background: There is a paucity of literature assessing the incidence and characteristics of acute and chronic thromboembolic events following septic versus aseptic revision knee arthroplasty. The current study aimed to evaluate these complications between these populations.

Methods: This retrospective cohort study used a national database (2010 to 2022) to examine postoperative outcomes in patients who underwent aseptic or septic revision total knee arthroplasty (TKA). Outcomes of interest included acute thromboembolic events such as pulmonary embolism (PE), deep vein thrombosis (DVT), myocardial infarction (MI), cerebrovascular disease (CVD), precerebral occlusion, and chronic thromboembolic events such as chronic thromboembolic pulmonary hypertension, post-thrombotic syndrome, limb ischemia, lower-limb amputation, chronic PE, and secondary pulmonary hypertension. A 1:1 matching was used to control for baseline differences, and multivariate logistic regressions were conducted to compare complication rates between the matched groups.

Results: Septic revision arthroplasty cohorts demonstrated increased rates of PE (odds ratio [OR] = 2.65, 2.45; P < 0.001), DVT (OR = 3.83, 3.35; P < 0.001), MI (OR = 3.49, 3.33; P < 0.001), CVD (OR = 3.39, 2.62; P < 0.001), and precerebral occlusion (OR = 3.21, 2.22; P < 0.001) at 30- and 90-day timepoints, respectively. The same cohort showed increased rates of limb ischemia (OR = 3.11, P < 0.001), lower-limb amputation (OR = 5.99, P < 0.001), chronic PE (OR = 1.65, P < 0.001), and secondary pulmonary hypertension (OR = 2.01, P < 0.001) at two years compared to aseptic revision cohorts. There was no significant difference observed regarding chronic thromboembolic pulmonary hypertension and post-thrombotic syndrome.

Conclusion: Septic revision arthroplasty is associated with increased rates of chronic and acute thromboembolic events. Further studies should be performed to evaluate possible underlying mechanisms of these findings.

Background: A greater trochanteric (GT) fracture after primary total hip arthroplasty (THA) is a clinically relevant complication that can lead to gait abnormalities and chronic lateral hip pain. Early postoperative GT avulsion fractures are rare, possibly resulting from poor bone quality or the use of two transosseous drill holes for posterior capsular repair. Computer- and robotic-assisted surgery may increase fracture risk due to cortical defects from temporary pins. This study aimed to assess the rate of early GT fractures and identify contributing factors and prevention strategies.

Methods: This was a retrospective review of patients who underwent a posterior approach primary THA at our institution between January 1, 2016, and December 31, 2022, and subsequently presented with a GT avulsion fracture. Patient demographics, procedure details, implanted components, surgical technique, and postoperative fracture radiographs were reviewed, with descriptive statistics calculated for all variables.

Results: There were 39 GT avulsion fractures identified among 18,873 posterior approach primary THAs, yielding an absolute risk of 0.2%. Of these, 97% occurred in women (mean age of 73 years, mean body mass index of 26). All avulsion fractures were atraumatic and occurred early, at an average of 27 days, during routine activities. The majority (59%) of the patients who had GT avulsion fractures had confirmed low bone density. In addition, 90% of avulsion fractures occurred in cases with two drill holes for posterior capsular repair, and 64% (25 of 39) involved computer navigation or robotic assistance. Of the 39 cases, 59% used a fit-and-fill stem, whereas 41% used a tapered wedge stem. Offset and leg length were increased by an average of 5.4 and 4.5 mm, respectively, on the affected hip.

Conclusions: Atraumatic GT avulsion fractures after posterior approach THA are a clinically important complication. Factors such as women, low bone density, increased femoral offset, and the two-drill-hole technique for soft tissue repair may be associated with this complication. Consideration for a single or no drill hole for the posterior repair technique may reduce the risk of this complication.

Background: Serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are used to screen for periprosthetic joint infection (PJI) of total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). However, PJI may exist in the absence of elevated ESR and CRP. We aimed to report the incidence of seronegative PJIs in THAs and TKAs and the utility of arthrocentesis for PJI workup.

Methods: We identified 925 total joint arthroplasties (312 THAs, 613 TKAs) that had surgical management of a chronic PJI from 2013 to 2022 at a single institution. All cases met the 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI. Seronegative PJI was defined as meeting the MSIS criteria for PJI with a preoperative ESR of less than 30 mm/hour and CRP of less than 10 mg/L. Hips and knees were analyzed separately.

Results: Out of 925 chronic PJIs, 10% of THAs (n = 32) and 4% of TKAs (n = 24) were seronegative PJIs. Among these, 94% of hips and 92% of knees met more than one major MSIS criterion, with 94 and 92% of seronegative hips and knees, respectively, having at least two positive intraoperative cultures with the same organism. A positive culture from preoperative aspiration was obtained from 84 and 81% of seronegative hips and knees, respectively. The most common infecting organism overall was Staphylococcus epidermidis (25% of hips and 38% of knees), followed by Cutibacterium species (16%) for hips and polymicrobial infections (23%) for knees.

Conclusions: Serum ESR and CRP were normal in 10 and 6% of chronic hip and knee PJIs, respectively. An arthrocentesis before revision surgery was able to identify 84 and 81% of seronegative hip and knee PJIs, respectively, highlighting the importance of arthrocentesis prior to revision THA and TKA. Our findings suggest that serum ESR/CRP should not be utilized in isolation to definitively rule out PJI.

Level of evidence: III (retrospective).