Acta Orthopaedica最新文献

Background and purpose:  Adding antioxidant to highly cross-linked polyethylene (XLPE) is proposed to improve oxidation resistance and decrease wear in total hip replacements (THR), but long-term performance is unknown. We aimed to compare the revision rates of THR using cementless acetabular components where the insert was made of either XLPE with antioxidant (AOXLPE) or XLPE, using data from a large national registry.

Methods:  The population was THR from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) in the 10-year period 2014-2023 with modular cementless acetabular components and ceramic or metal femoral heads used for osteoarthritis. We compared primary THR using XLPE with antioxidant (AOXLPE) acetabular inserts with XLPE acetabular inserts. The outcome measured was all-cause revision. Cumulative percentage revision (CPR) was calculated using the Kaplan-Meier method, and comparisons made using Cox proportional hazards models.

Results:  There were 198,073 THRs, of which 35,309 had AOXLPE inserts. There were 769 and 4,327 revisions with AOXLPE and XLPE inserts, respectively. While there was no early difference, the AOXLPE group had a lower revision rate after 3 years (HR 0.64, 95% confidence interval [CI] 0.48-0.84). When adjusted for multiple factors the AOXLPE group still had a lower revision rate after 3 years (HR 0.63, CI 0.47-0.83). Revisions for loosening, wear-related causes, and fracture were proportionately lower in the AOXLPE group, but no difference was found with revisions for dislocation/instability or infection.

Conclusion:  While there was no early difference, THR with AOXLPE acetabular inserts had a lower revision rate after 3 years than XLPE. This suggests a possible clinical benefit using AOXLPE but the difference may, in part, be related to the associated femoral or acetabular components.

Background and purpose:  Management of pediatric distal forearm fractures ranges from no or simple immobilization to surgical fixation. Treatment decisions depend on age and fracture severity, but practices vary widely across countries. As surgical intervention has increased internationally, we aimed to investigate national trends in incidence and treatment of pediatric distal forearm fractures in Denmark from 1999-2018 Methods: We conducted a population-based register study of children aged 0-15 with distal forearm fractures (S525 + S526) registered in the Danish National Patient Registry from 1999-2018. Treatments within 1 week of injury were grouped into: non-surgical (no immobilization, soft bandage or cast immobilization), closed reduction and immobilization, and surgical fixation. Procedure codes included closed reduction, open reduction, K-wires, or other fixations such as external fixation, nail, plate, or screws.

Results:  There were 175,083 fractures over the 20 years, yielding a mean incidence of 829/100,000/year in children aged 0-15 years. The highest incidences were 1,494/100,000 among 11-year-old girls and 1,720/100,000 among 13-year-old boys. The primary treatment in all age groups was non-surgical treatment, though decreasing from 92% in 1999 to 89% in 2018. The proportion of closed reduction declined from 7% to 2%, while K-wire fixation increased from 1% to 8%. When stratified by age groups, the same trend was seen in all but the 0-3-year-olds.

Conclusion:  The overall incidence remained stable during the study period. Non-surgical treatment remained predominant, whereas closed reductions decreased in favor of more K-wire fixations.

Background and purpose:  Migration is an early sign of loosening. We investigated the migration and stability of the cemented Persona Partial Knee (PPK, Zimmer Biomet, Warsaw, IN, USA), for both the femoral and tibial component, and evaluated the clinical results at 5 years' follow-up.

Methods:  In this prospective cohort study, primary cemented PPKs were implanted. Migration of the tibial and femoral component at 5 years postoperatively was calculated using model-based radiostereometric analysis (mRSA) in terms of translations and rotations. To evaluate the clinical results, a clinical examination was performed using the Knee Society Score (KSS), and PROMs (NRS pain, KOOS-PS, OKS, EQ-5D) were registered.

Results:  26 patients were included. At 5 years postoperatively, we found low migration of both the tibial and femoral component, namely a translation of < 0.21 mm and rotation of < 0.75° in all directions for both components. Compared with 2 years' follow-up, the tibial components showed an increased total translation and total rotation at 5 years. The femoral components showed stable migration compared with 2 years' follow-up. The KSS decreased between 2 and 5 years, while the PROMs remained stable between 2 and 5 years' follow-up.

Conclusion:  The PPK showed low migration of both the tibial and femoral components at 5 years' follow-up. The femoral component was stable between 2 and 5 years, while the tibial component still migrated.

Background and purpose:  Total hip arthroplasty (THA) in young patients is rare but increasingly performed. We aimed to analyze implant survivorship and risk factors for revision in patients aged 30 years or less after THA based on the German Arthroplasty Registry (EPRD).

Methods:  Kaplan-Meier survival analysis and Cox proportional hazard models were used to analyze the EPRD dataset from 2013 to 2023 for factors associated with increased risk of revision. The primary outcome was first revision operation.

Results:  1,622 primary THAs in 1,452 patients were analyzed. The mean age was 26 years (range 11-30), 908 (56%) of whom were male. The most frequent diagnosis was secondary osteoarthritis (1,146, 72%), followed by osteonecrosis (357, 22%), and hip dysplasia (53, 3.2%). Of all THAs, 1,601 (99%) were uncemented, and 1,574 (97%) received ceramic heads. The average follow-up period was 3.7 years (range 0-10.6). 47 hips were revised with a cumulative revision rate (CRR) at 8 years of 4.6% (95% confidence interval [CI] 2.8-7.3). The most frequent revision cause was infection in 11 cases (0.7%). Increased revision risk was associated with pediatric hip disease for those with prior surgery for Perthes, HR 4.3 (CI 1.9-9.6), pelvic osteotomy HR 2.8 (CI 1.1-7.5), and a primary diagnosis of hip dysplasia, HR 3.4 (CI 1.3-8.5).

Conclusion:  Uncemented THA in young patients demonstrated a revision rate of 4.6% (CI 2.8-7.3), which we believe is a satisfactory mid-term survival. Patients with pediatric hip disease present the highest risk of revision.

Background and purpose: Developmental dysplasia of the hip (DDH) affects around 1.5% of newborns in Sweden with few late detected cases (0.12 per 10,000). The most common treatment for DDH in Sweden is with the von Rosen splint, with radiographs at 3 and 12 months of age. Little is known about the remodeling of acetabular dysplasia following treatment initiated in the neonatal period. We aimed to examine the correlation between the acetabular index (AI) at 3 and 12 months.

Methods:  We included 228 patients with early detected DDH with dislocatable hips (Barlow) and dislocated hips (Ortolani), treated with the von Rosen splint at Skåne University Hospital 2003-2019. The treatment length was 6 weeks for 96 children and 12 weeks for 132 children. We calculated the correlation between AI at 3 and 12 months using Pearson correlation (r) and the mean difference, both with 95% confidence intervals (CI).

Results:  The correlation between AI at 3 and 12 months was moderate, r = 0.43 (95% confidence interval [CI] 0.35-0.50), with changes in AI that differed widely. The mean AI was 23.9° (CI 23.5-24.3) at 3 months and 24.9° (CI 24.6-25.3) at 12 months with a difference of 1.0° (CI 0.6-1.3).

Conclusion:  The correlation between AI at 3 and 12 months was moderate, with non-clinical difference for both 6 and 12 weeks of treatment. The small increase in mean AI was most likely explained by a low AI at 3 months after 12 weeks of treatment.

Background and purpose:  The 2 most common surgical approaches in hemiarthroplasty for hip fracture treatment are the posterolateral and the direct lateral approach. We aimed to estimate the relative cost-effectiveness of these approaches.

Methods:  We conducted an economic evaluation alongside a randomized controlled superiority trial for 6 months. The trial included 555 patients over 18 years of age with an acute femoral neck fracture. The effectiveness outcome used was quality-adjusted life years (QALYs), assessed using the EQ-5D-5L. Costs were measured through self-reported questionnaires administered at baseline, after 3 months, and after 6 months. We dealt with missing data through multiple imputation and analyzed the imputed datasets by comparing group means in costs and QALYs. A secondary analysis included adjustment for baseline imbalances through linear regression.

Results:  The estimated average treatment effect on the QALYs was 0.02 (95% confidence interval [CI] -0.006 to 0.046). From the healthcare and societal perspective, we found a non-significant average treatment effect on costs of 1,508 (CI -1,744 to 4,760) and 1,583 (CI -1,972 to 5,137), respectively. The probability of cost-effectiveness was 10% at a willingness-to-pay of zero, and then slowly increased to around 50% for higher willingness-to-pay values.

Conclusion:  We found no conclusive evidence of any differences between the surgical approaches with respect to costs, QALYs, and cost-effectiveness. We therefore suggest that, from an economic viewpoint, the 2 surgical approaches should be treated as interchangeable.

Background and purpose:  In patients with knee osteoarthritis (OA), psychological factors (anxiety, depression, and pain-related catastrophizing) are associated with more pain and worse physical function. Low knee awareness and high knee-related quality of life (QoL) are key indicators of a well-functioning knee. The objective of our study was to evaluate associations between psychological factors and knee awareness and knee-related QoL in patients with knee OA.

Methods:  In this Norwegian cross-sectional study of 653 patients with knee OA, 4 psychological factors were assessed: anxiety, depression, pain-related catastrophizing, and fear avoidance of physical activity. Associations between these factors and knee awareness and knee-related QoL were examined in unadjusted and adjusted regression models, controlling for age, sex, BMI, pain, and whether patients accepted or declined inclusion in a randomized controlled trial (ClinicalTrials.gov: NCT03771430). Regression coefficients with values below zero indicate negative associations between the independent and dependent factors and values above zero indicate positive associations.

Results:  Worse scores on all 4 psychological measures were associated with higher knee awareness and poorer knee-related QoL in unadjusted analyses. Standardized estimates (βs) ranged from -0.38 (95% confidence intervals [CI] -0.45 to -0.31) to -0.16 (CI -0.23 to -0.08). In adjusted analyses, pain catastrophizing (β -0.07, CI -0.14 to -0.01) and fear-avoidance (β -0.11, CI -0.18 to -0.05) remained associated with higher knee awareness, whereas poorer knee-related QoL remained associated with more anxiety (β -0.10, CI -0.16 to -0.03) and depression (β -0.14, CI -0.20 to -0.08), as well as more pain catastrophizing (β -0.19, CI -0.26 to -0.12) and fear-avoidance (β -0.19, CI -0.25 to -0.13).

Conclusion:  Higher fear avoidance of physical activity and more pain catastrophizing had the strongest associations with higher knee awareness and poorer knee-related QoL.

Background and purpose:  Both cemented and uncemented stem fixation is used in 2-stage hip revision arthroplasty addressing periprosthetic joint infection (PJI). We aimed to compare the risk of infection relapse and the risk of reoperation for any reason between uncemented and cemented stem fixation.

Methods:  Patients who underwent 2-stage hip revision arthroplasty for PJI between 2005 and 2020 were included. Data on baseline demographics, implant type, and microbiological and antibiotic treatment data was obtained from a local registry and medical records. Kaplan-Meier analysis compared relapse-free survival and reoperation-free survival between uncemented (n = 60) and cemented (n = 34) stems. Cox regression models were fitted to assess adjusted hazard ratios (aHR) for the risk of relapse or reoperation with 95% confidence intervals (CIs).

Results:  94 patients underwent 2-stage revision hip arthroplasty for PJI. Unadjusted 2-year relapse-free survival rates were 95% (CI 89-100) for patients with uncemented stem fixation and 97% (CI 90-100) for those with cemented fixation. Reoperation-free survival at 10 years was 82% (CI 70-95) for patients with uncemented fixation and 61% (CI 43-85) for those with cemented fixation. Using cemented fixation as the reference, the aHR for infection relapse was 2.0 (CI 0.2-20.1, P = 0.6) for uncemented fixation, whereas the aHR for reoperation was 0.3 (CI 0.1-0.9, P = 0.03).

Conclusion:  We showed no statistical difference in the risk of infection relapse, but uncemented stem fixation in 2-stage revision arthroplasty for PJI was associated with a reduced risk of reoperation for any reason. Uncemented stems may thus be a suitable choice in 2-stage revisions for PJI when this concept is believed to provide better fixation.

Background and purpose:  Computed tomography (CT) has become a valuable tool for preoperative planning and perioperative, real-time navigation during total hip arthroplasty (THA). CT can also quantify postoperative implant migration without the need for implanted bone markers, making it a promising alternative to the current gold standard radiostereometric analysis (RSA). Our aim was to evaluate the accuracy of preoperative planning and postoperative implant migration of both cup and stem employing AI-based software using 3D CT-images (CT-RSA) compared with conventional RSA.

Methods:  26 patients with primary THA were preoperatively 3D-planned and perioperatively navigated. They were followed and analyzed with AI-based CT-RSA within 2 days postoperatively and at 3, 12, and 24 months. 10 of the patients had implanted tantalum markers at surgery and were also followed up with conventional model-based RSA (MBRSA). The results were compared with CT-RSA. Prosthetic CAD models were used for both conventional RSA and AI-based CT-RSA analysis. Double CT and MBRSA scans were taken to evaluate precision. The preoperative plan was compared with actual perioperatively chosen implants.

Results:  AI-based CT-RSA showed consistent migration patterns, with most migration in the first 3 months, which then levelled out. Bland-Altman plots indicated good agreement between MBRSA and AI-based CT-RSA. Overall, there was high correspondence between MBRSA and AI-based CT-RSA in translations, but more divergent rotation results. AI-based CT-RSA precision was consistently slightly better than MBRSA precision. The agreement between planned and actual size of cup was 25 out of 26, and 23 out of 26 for stems.

Conclusion:  AI-based CT-RSA demonstrated accuracy comparable to MBRSA, with slightly improved precision and reduced user-dependence. The same system also provided an accurate and predictable preoperative implant plan.