Journal of Arthroplasty最新文献

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).

Background: Preincision antibiotic prophylaxis reduces infection risk in total knee arthroplasty, but its role in revision procedures for periprosthetic joint infection (PJI) remains uncertain. Early antibiotic administration may suppress culture yield or alter concordance with preoperative aspiration, potentially leading to false-negative results that complicate postoperative antimicrobial selection.

Methods: This retrospective multicenter study identified 576 chronic knee PJI patients who underwent two-stage exchange arthroplasty with a minimum of 1-year follow-up. A PJI was defined using the 2013 Musculoskeletal Infection Society criteria. Patients who did not have preoperative synovial aspirations or who were receiving outpatient antibiotic treatment within 2 weeks of aspiration or revision surgery were excluded (n = 182). Preoperative synovial aspirate cultures, intraoperative tissue cultures, and antimicrobial prophylaxis regimens were recorded. Antibiotic prophylaxis was administered before incision in 49% and withheld in 51%. Pearson Chi-square tests and one-way analyses of variance were used to determine whether antibiotic timing affected culture yield, proportion of positive culture results, and concordance with prior synovial aspirate results.

Results: Intraoperative culture positivity was similar between early and delayed antibiotic groups (63 versus 63%, P = 0.960), regardless of antibiotic class. Aspirate-to-tissue concordance was also comparable (85 versus 80%, P = 0.225). Among patients who had positive preoperative aspirates, intraoperative culture yield was unaffected by antibiotic timing (89 versus 87%, P = 0.531). However, in those who had negative preoperative aspirations, withholding antibiotics significantly improved culture yield (49 versus 29%, P = 0.015). The number of intraoperative samples was not associated with culture positivity.

Conclusions: The timing of antibiotic prophylaxis does not influence overall intraoperative culture yield or aspirate concordance in revision total knee arthroplasty for PJI. However, in patients who have negative preoperative aspirations, withholding antibiotics significantly improves the likelihood of identifying a pathogen. Surgeons should consider delaying prophylaxis in this subgroup to optimize microbiologic diagnosis.

Level of evidence: Level III, retrospective comparative study.

Background: Coronal plane deformity in total knee arthroplasty (TKA) can introduce major variability in difficulty between cases based on the type and degree of deformity. The purpose of this study was to compare the energy expenditure of TKA in varus and valgus knees.

Methods: There were 85 patients undergoing primary, elective cemented TKA who were prospectively enrolled, and various demographic and surgical variables were collected. Surgeon physiologic parameters were collected via a smart garment that recorded heart rate variability (beats per minute), minute ventilation (mL/minute), and energy expenditure (kcal). Patients who had coronal plane deformities of various degrees were stratified into different groups based on severity: mild varus (N = 31), moderate/severe varus (N = 28), mild valgus (N = 17), and moderate/severe valgus (N = nine). A coronal plane deformity of 10° was the threshold for moderate/severe deformity. Analysis of variance models were used to compare demographics and surgeon physiologic stress between groups. There were differences in age and sex between cohorts (P < 0.05), whereas other demographics were comparable (P > 0.05).

Results: Energy expenditure was significantly different across deformities, with valgus knees and increased deformity having the highest expenditure (P < 0.001). Heart rate variability and minute ventilation did not differ across cohorts (P = 0.23). In the regression models, energy expenditure remained significantly higher with mild (P = 0.017) and moderate/severe valgus (P = 0.001) compared to mild varus. Heart rate variability was also significantly increased in these groups (P = 0.03).

Conclusions: Surgeons expend varying degrees of energy during TKA depending on the type and degree of deformity. Total knee arthroplasty in the setting of severe valgus deformity is associated with the most physiologic demand for the surgeon. These data provide quantifiable measures for the degree of case difficulty, which is pertinent for proper compensation for appropriate work.

Background: Primary total knee arthroplasty (TKA) has shifted from inpatient to outpatient facilities in the United States, driven by surgical advances, the 2018 Center for Medicare & Medicaid Services inpatient-only list change, and COVID-19 pressures. Limited national data and unclear patient profiles in outpatient facilities versus hospitals prompt this study. Outpatient TKA patients are often younger and have fewer comorbidities, but safety debates persist. Using a national database, we examined (1) trends in knee arthroplasty settings, (2) demographic differences, and (3) comorbidity variations to inform patient selection, outcomes, and policy.

Methods: We conducted a retrospective analysis using two national databases from 2019 to 2022. Adult patients undergoing elective, unilateral, primary TKA were identified using validated coding algorithms. We analyzed temporal trends in procedure location and compared demographic and comorbidity profiles between patients treated in hospitals versus outpatient facilities.

Results: A total of 50% of the volume of primary TKA migrated to outpatient centers from 2019 to 2022. The proportion of hospital-based TKAs declined from 64 to 14%, whereas ambulatory surgical center (ASC)-based procedures rose from 36 to 86%. The ASC patients were younger (67.2 versus 67.6 years, P < 0.01), more likely to be White (78.6 versus 77.6%, P < 0.01), and more likely to have commercial insurance (P < 0.01). Hospital-based patients had significantly higher rates of nearly all comorbidities than those in outpatient facilities.

Conclusions: There has been a dramatic national migration of TKA procedures from inpatient hospitals to ASCs over the last 4 years. Patients selected for ASC-based TKA tend to be healthier and demographically distinct. These findings underscore the need for careful patient selection and ongoing evaluation of outcomes to ensure safety and equity in the delivery of outpatient TKA.