Acta Orthopaedica, owned by the Nordic Orthopaedic Federation, is a non-profit electronic, immediate Open Access journal, meaning your work is free for every-one to access online as soon as it’s published (Gold OA). The journal presents articles, from all parts of the world, of basic research interest, as well as clinical studies in the field of orthopedics and related subdisciplines
Acta Orthopaedica (Scandinavica) content is available freely online as from volume 1, 1930. The journal owner owns the copyright for all material published until volume 80, 2009. As of June 2009, the journal has however been published fully Open Access, meaning the authors retain copyright to their work. As of June 2009, articles have been published under CC-BY-NC or CC-BY licenses, unless otherwise specified.
Vaccination is associated with reduced mortality rates after surgery for hip fractures in the setting of recent COVID-19 infection: an observational study from the Kaiser Permanente Northern California Database
Background and purpose: Limited data exist on mortality and venous thromboembolism (VTE) risk in hip-fracture patients with recent COVID-19 infection. We aimed to examine (i) the association between vaccination status and mortality risk, (ii) whether infection timing is associated with mortality risk, and (iii) whether recent infection is associated with an increase in postoperative VTE risk. Methods: Adult Kaiser Permanente Northern California members undergoing hip-fracture surgery (2020–2022) were identified. Patients with varying vaccination statuses and SARS-CoV-2 infection histories within 6 months preoperatively were analyzed. Multivariable regression models were adjusted for demographics, comorbidities, and COVID-19 status to calculate risk ratios. The primary outcome was 90-day mortality; the secondary outcome was 90-day VTE. Results: 3,674 patients were included. Unvaccinated or partially vaccinated patients with COVID-19 within 6 months preoperatively had a 4.49-fold higher 90-day mortality risk than fully vaccinated patients (95% confidence interval [CI] 3.72–5.42). Among COVID-positive patients, shortening of the interval from infection to surgery from 6 months to 6 weeks was associated with increased 90-day mortality risk of approximately 53% (CI 1.29–1.97). Additionally, more recent infection (within 6 months) was associated with a 3.14-fold higher postoperative VTE risk (CI 1.10–8.98). Conclusion: COVID-19 vaccination is associated with a reduction in the mortality risk among hip-fracture patients with recent infection. Shorter infection-to-surgery intervals are associated with increased mortality risk, and recent infection is associated with higher VTE risk.
Copyright (c) 2026 Aidan T Morrell, Ryland P Kagan, Mackenzie Kelly, Graham J Dekeyser, Andrew L Avins, Lusine X Gigoyan, John S Cox https://creativecommons.org/licenses/by/4.0
1-year results after surgery for flexible adult-acquired flatfoot deformity: a cohort study based on 190 patients from the Swedish Foot and Ankle Surgery Register
Background and purpose: Surgical outcomes in patients with flexible adult-acquired flatfoot deformity (AAFD) have not been evaluated in large prospective register studies. Calcaneal osteotomy and hindfoot arthrodesis are commonly used. We aimed to compare the results of these 2 procedures using preoperative and 1-year postoperative patient-reported outcome data from the Swedish Quality Register for Foot and Ankle Surgery (Swefoot). Methods: We analyzed data regarding feet that had primary surgery for flexible (grade II) AAFD between 2017 and 2022 in Sweden. The primary outcome was the Self-Reported Foot and Ankle Score (SEFAS), range 0–48 (minimal important difference 5). Secondary outcomes were EQ-5D and satisfaction. Results: 190 feet (63% women, median age 62 years, interquartile range 54–68) were surgically treated during the study period. Mean improvement in SEFAS score was 12 (95% confidence interval [CI] 10–13) in grade IIa and 10 (CI 8–12) in grade IIb, and in the EQ-5D index 0.27 (CI 0.20–0.34) and 0.23 (CI 0.15–0.31), respectively. Compared with preoperatively a higher percentage of patients were satisfied with postoperative foot appearance (77% vs 39%) and foot strength (66% vs 23%). The mean SEFAS score improvement was 11 (CI 10–13) in the osteotomy group and 10 (CI 5–15) in the arthrodesis group; adjusted mean difference was 2.7 (CI –1.2 to 6.5). Conclusion: Surgical treatment of flexible AAFD significantly improves function and quality of life at 1 year postoperatively. No differences in postoperative patient-reported outcomes were observed between patients who underwent calcaneal osteotomy compared with hindfoot arthrodesis.
Copyright (c) 2026 Ida Karin Johanna Osbeck, Maria Cöster, Isam Atroshi https://creativecommons.org/licenses/by/4.0
No difference in patient-reported outcome measures between private and public hospitals in the Netherlands: a cross-sectional analysis based on 170,150 hip and knee arthroplasties from the Dutch Arthroplasty Register
Background and purpose: Private hospitals have become more frequent healthcare providers for arthroplasty surgery in the Netherlands. The aim of our study was to assess patient-reported outcome measures (PROMs) in patients who received primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA) in private hospitals compared with patients from public hospitals, and to assess access to care based on mean travel distance to the healthcare facility. Methods: Patients operated on between 2014 and 2023 were included. Patient characteristics, preoperative, 3- or 6-, and 12 months postoperative PROMs (Numeric Pain Rating Scale [NRS] pain, EuroQoL 5-Dimensions [EQ-5D-5L], Hip disability and Osteoarthritis Outcome Score [HOOS-PS], Knee Injury and Osteoarthritis Outcome Score [KOOS-PS], Oxford Hip Score [OHS], and Oxford Knee Score [OKS]) were retrieved from the LROI. For analysis, repeated measurements were performed, using mixed-effect models adjusted for confounders. Primary endpoints for inference were NRS pain during activity, HOOS/KOOS-PS, and OHS/OKS at 3 months follow-up. Mean travel distance to the hospital was compared, as measure for access to care. Results: 146,303 primary THAs, TKAs, and UKAs performed in public hospitals and 23,847 in private hospitals were included. Patients undergoing arthroplasty in private hospitals were generally younger and had a higher socioeconomic status and lower body mass index and American Society of Anesthesiologists Physical Status class. Both patients from private and public hospitals improved similarly and significantly after surgery. At 3-month follow-up, public hospitals showed marginal but statistically significant advantages in HOOS/KOOS-PS for THA, TKA, and UKA (mean differences 0.5 [95% confidence interval (CI) 0.1–0.9], 0.5 [CI 0.1–0.9], and 1.3 [CI 0.5–2.1], respectively). OKS favored public hospitals for TKA and UKA (–0.4 [CI –0.6 to –0.2] and –0.6 [CI –1.0 to –0.1]). NRS pain during activity favored private hospitals for TKA (–0.2 [CI –0.3 to –0.1]). All absolute differences were small and without statistical significance. Mean travel distance was significantly shorter for patients treated in public hospitals. Conclusion: There is no difference in PROMs between public and private hospitals after primary THA, TKA and UKA in the Netherlands. Based on mean travel distance, access to care was not compromised for high-risk patients.
Copyright (c) 2026 Marije Carlijn Vink, Pelle Bos, Bart-Jan van Dooren, Rinne M Peters, Liza N van Steenbergen, Enrico de Visser, J Martijn Brinkman, B Willem Schreurs, Wierd P Zijlstra https://creativecommons.org/licenses/by/4.0
Psychological factors associated with trial participation among patients eligible for total knee arthroplasty with a non-surgical treatment arm: a comparative cross-sectional study
Background and purpose: Knowledge of psychological factors’ influence on patients’ decisions to participate in randomized controlled trials (RCTs) is scarce. We aimed to compare levels of psychological factors in patients with knee osteoarthritis (OA) eligible for total knee arthroplasty in those who agree to participate in an RCT with those who declined. Methods: We compared anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), pain-related fear of movement (Fear-Avoidance Belief Questionnaire [FABQ]), catastrophizing (Pain Catastrophizing Scale [PCS]), knee symptoms (Knee Osteoarthritis and Outcome Scale [KOOS]), and knee awareness (Forgotten Joint Score [FJS]), in patients in the Multidisciplinary Intervention in Total Knee Arthroplasty (MultiKnee) trial (n = 280) and in patients who declined (n = 373). Simple and multiple logistic regression models explored associations between psychological factors and patients’ willingness to participate. Results: Patients declining participation had more fear avoidance (FABQ 1.6 points higher, 95% confidence interval [CI] 0.6–2.6), more knee awareness (FJS 4.0 points lower, CI 1.9–6.1), and worse KOOS scores (ranging from 3.4, CI 0.6–6.1 to 5.6 points, CI 3.1–8.2). In simple regression analysis, each 1-point increase in FABQ-Physical activity score was associated with a 3.9% decrease in odds of participating (OR 0.96, CI 0.94–0.99), and in adjusted analyses, a 3.0% decrease in odds (OR 0.97, CI 0.94–1.0). When considering a clinically meaningful difference of 4 points, this corresponds to a 14.7% reduction in crude odds and a 11.5% reduction in adjusted odds of study participation. Each 1-point increase in HADS Anxiety score was associated with a 5.4% increase in odds of participating (OR 1.05, CI 1.00–1.11). HADS Depression and PCS were not associated with RCT participation. Conclusion: Patients with higher fear avoidance of physical activity were less willing to participate in the RCT, while patients with higher anxiety were more willing. These findings may weaken the generalizability of the findings from the RCT.
Copyright (c) 2026 Nina Jullum Kise, Siri Eliassen, Caryl L Gay, Anners Lerdal, Maren Falch Lindberg, Tor Kjetil Nerhus, Turid Rognsvåg, Arild Aamodt, Stig Heir https://creativecommons.org/licenses/by/4.0
What aspects of pain and functional outcomes contribute to patient satisfaction 1 year after surgery within total hip and total knee arthroplasty populations? A registry-based cohort study
Background and purpose: Patient satisfaction after total hip and knee arthroplasty (THA, TKA) is influenced by multiple factors, including patient-reported pain and function. We aimed to examine whether functional abilities or pain during specific activities are associated more than other aspects with satisfaction 1 year after THA and TKA. Methods: This cohort study included all primary elective THAs and TKAs performed between January 2012 and June 2022 at a tertiary care university hospital. Ordinal logistic regression models were used to assess associations between patient satisfaction and WOMAC Pain and Function summary scores and items, 1 year postoperatively. Results: 1,772 THAs and 1,323 TKAs were included. Individually, all scores and items were associated with satisfaction. However, multivariable models revealed differences in the strength of association. Global pain score (odds ratio [OR] THA: 2.80, 95% confidence interval [CI] 2.40–3.29; TKA: 3.61, CI 2.96–4.44), pain while walking on the flat (OR THA: 1.79, CI 1.45–2.22; TKA: 1.74, CI 1.43–2.11), and pain going up or down stairs (OR THA: 1.64, CI 1.37–1.96; TKA: 1.68, CI 1.44–1.97) showed the strongest associations in both populations. Among THAs, activities walking on the flat (OR 1.41, CI 1.17–1.68), putting on socks (OR 1.29, CI 1.12–1.48), and ascending stairs (OR 1.26, CI 1.08–1.46) contributed most to satisfaction, whereas among TKAs, walking on the flat (OR 1.41, CI 1.18–1.69), rising from sitting (OR 1.32, CI 1.11–1.58), and getting in or out of a car (OR 1.31, CI 1.10–1.57) did. Conclusion: After THA/TKA, patient satisfaction is associated with pain during basic daily tasks—especially walking and stair climbing. Key functional drivers differ by joint: socks and stairs matter for THA, rising from sitting and getting in/out of a car matter for TKA.
Copyright (c) 2026 Marys Revaz, Thomas Perneger, Christophe Barea, Hermes H Miozzari, Didier Hannouche, Anne Lübbeke https://creativecommons.org/licenses/by/4.0
Increased all-cause mortality following distal radius fractures in Danish adults: a register-based matched cohort study
Background and purpose: Distal radius fractures (DRFs) are common in older adults and are associated with osteoporosis and underlying frailty. While hip and spine fractures are associated with increased mortality, the association between DRFs and all-cause mortality remains less clear. We aimed to assess all-cause mortality risk following DRF in Denmark compared with age- and sex-matched controls. Methods: We conducted a nationwide, register-based matched cohort study using data from the Danish National Patient Register and Civil Registration System (1998–2018). Adults (≥ 18 years) with a DRF were matched 1:5 to controls by sex and birthdate ± 30 days. Mortality rates per 103 persons and mortality rate ratios with 95% confidence intervals (CIs) were calculated at 30, 90, 365, and 730 days after the fracture. Results: We included 190,513 patients with DRF and 952,565 controls (70% female, mean age 59 years). Mortality rates were higher for patients with DRF compared with controls across all age categories, particularly in men and within the first 30 days. Among men, mortality rates ranged from 0.36 to 52.9 per 1,000 persons in patients with DRF and from 0.07 to 20.0 per 1,000 persons in controls. Among women, mortality ranged from 0.16 to 26.3 per 1,000 persons in patients with DRF and from 0.04 to 15.9 per 1,000 persons in controls. Mortality rate ratios were highest for the 50–59 age category (male: 4.60, CI 3.95–5.35, female 3.08, CI 2.80–3.39), decreasing with higher age. Mortality rate ratios stabilized after 365 and 730 days. Conclusion: This nationwide study shows increased all-cause mortality among patients with DRF compared with sex and age-matched controls, with the highest mortality rate within the first 30 days after the fracture. The mortality rate ratio was consistently higher in the age-group 50–59 and among males.
Copyright (c) 2026 Cecilie Rud Budtz, Antti P Launonen, Bakir O Sumrein, Stig Brorson, Helle K Østergaard, Merete N Madsen https://creativecommons.org/licenses/by/4.0
Intraoperative single-dose methadone significantly affects postoperative morphine consumption in older patients with a hip fracture: the MetaHip randomized controlled trial
Background and purpose: Effective pain management in older patients with a hip fracture is critical for postoperative recovery. Our primary objective was to compare intraoperative methadone with placebo on postoperative morphine consumption over 72 hours. Methods: Patients aged ≥ 60 years with hip fractures were randomized to receive methadone (0.10 mg/kg) or placebo intraoperatively. The primary outcome was postoperative morphine consumption measured in 24-hour intervals over 72 hours. Secondary outcomes included pain scores, time to mobilization, and discharge. Harms were assessed as adverse and serious adverse events. Results: 129 patients were included. The primary endpoint analysis demonstrated that postoperative morphine consumption over 72 hours differed significantly between groups (likelihood-ratio test, P = 0.02). Model-based estimates suggested lower morphine consumption in the methadone group at 0–24 hours (least square mean [LSM] 7.1 [SE 1.2] vs placebo 10.1 [SE 1.7] mg) and at 24–48 hours (4.1 [SE 0.8] vs placebo 5.3 [SE 0.9] mg). At 48–72 hours, the model suggested lower morphine consumption in the placebo group (3.2 [SE 0.6] vs methadone 4.6 [SE 0.9] mg). Secondary outcomes were similar between groups, except that time to hospital discharge was longer in the methadone group (LSM 5.6 vs 4.5 days; mean difference –1.3 days, 95% confidence interval –2.3 to –o.4; P < 0.01). Harms appeared comparable, although the low event rate precluded formal analysis. Conclusion: A single intraoperative dose of methadone significantly alters postoperative morphine consumption over 72 hours after hip fracture surgery, without major safety concerns.
Copyright (c) 2026 Kevin H Nygaard, Nikolaj H Schmidt, Lasse Eriksen, Sofie R Petersen, Thomas Strøm, Kirsten Specht, Jesper O Schønnemann https://creativecommons.org/licenses/by/4.0
Migration patterns of uncemented femoral stems in hip replacement: a systematic review and meta-analysis of clinical radiostereometric analysis cohort studies
Background and purpose: We conducted a systematic review and meta-analysis of radiostereometric analysis studies of primary uncemented femoral stems to investigate their subsidence and retroversion patterns and the migration patterns according to implant, patient, and study characteristics. Methods: A systematic search of PubMed, Web of Science, Cochrane, and Embase databases to identify all radiostereometric analysis studies on femoral stem migration following primary uncemented total hip replacement was performed. Clinical studies with 2 or more postoperative radiostereometric measurements within 2 years were included. Subsidence and retroversion at 6 weeks, 3 and 6 months, 1, 2, 5, and 10 years were included for analysis. Extracted implant characteristics included implant design, coating, and surgical approach. Data was analyzed using a random effects model. Results: 73 studies on 120 cohorts and 2,970 uncemented stems were included. 119 cohorts reported on subsidence and 91 on retroversion. The pooled subsidence at 3 months was 0.29 mm (95% confidence interval [CI] 0.19–0.39) and 0.32 mm (CI 0.21–0.43) at 2 years. The pooled retroversion at 3 months was 0.51° (CI 0.33–0.70) and 0.70° (CI 0.48–0.93) at 2 years. Hydroxyapatite-coated stems showed the least migration (subsidence 0.26 mm; CI 0.13–0.40; retroversion 0.51°; CI 0.22–0.80) among different coating types. The anterior approach showed more migration (subsidence 1.04 mm, CI 0.53–1.55; retroversion 1.52°, CI 1.08–1.95) than other surgical approaches. Conclusion: Our study shows that most subsidence and retroversion of uncemented femoral stems occurs during the first 3 months. Stabilization of subsidence occurred after 3 months, and retroversion stabilized after 2 years. Migration patterns differ based on stem type, coating, surgical approach, the time period when inclusion started, and timing of baseline measurement.
Copyright (c) 2026 Lisa van der Water, Christiaan H Righolt, Trevor Gascoyne, Bart L Kaptein, Rob G H H Nelissen, Bart G C W Pijls https://creativecommons.org/licenses/by/4.0
Response to Letter: Correlation between acetabular index at 3 and 12 months of age: a longitudinal radiographic study of 228 neonates treated for 6 or 12 weeks with the von Rosen splint for developmental dysplasia of the hip
Copyright (c) 2026 Adam Sand, Daniel Wenger, Henrik Düppe, Carl Johan Tiderius https://creativecommons.org/licenses/by/4.0
Letter to the Editor: Correlation between acetabular index at 3 and 12 months of age: a longitudinal radiographic study of 228 neonates treated for 6 or 12 weeks with the von Rosen splint for developmental dysplasia of the hip
Copyright (c) 2026 Soner Kocak https://creativecommons.org/licenses/by/4.0
Response to Letter: Machine learning-based prediction of short- and long-term mortality for shared decision-making in older hip fracture patients
Copyright (c) 2026 Hidde Dijkstra, Cathleen S Parsons, Hanne-Eva van Bremen, Hanna C Willems, Anne A H de Hond, Barbara C van Munster, Job N Doornberg, Jacobien H. F. Oosterhoff https://creativecommons.org/licenses/by/4.0
Letter to the Editor: Machine learning-based prediction of short- and long-term mortality for shared decision-making in older hip fracture patients
Copyright (c) 2026 Eda Yildirim https://creativecommons.org/licenses/by/4.0
Effect of an in-consult patient decision aid on decisional quality and involvement for patients with severe hip or knee osteoarthritis: a multicenter, cluster randomized controlled trial
Background and purpose: Shared decision-making (SDM) is important in managing patients with severe hip and knee osteoarthritis, where treatment decisions often depend on patient preferences and values. We aimed to evaluate the effectiveness of an in-consult patient decision aid in improving decision quality and patient involvement compared with usual care. Methods: In a cluster-randomized controlled trial, surgeons from 2 Danish orthopedic departments were randomized to use in-consult patient decision aids or provide usual care. The primary outcome was decision quality assessed using the Hip/Knee OA Decision Quality Instrument (HK-DQI). Patients who were well informed and received their preferred treatment received an Informed Patient-Centered (IPC) score of 1, indicating good decisional quality; all others scored 0. Secondary outcomes included patient-experienced engagement and involvement in decision-making, assessed using CollaboRATE and the decision-process domain of the Hip/Knee OA Decision Quality Instrument and consultation duration. Relative risks (RR) and mean differences (MD) with 95% confidence intervals (CIs) were estimated using multilevel regression models. Results: 20 surgeons were randomized to either use in-consult patient decision aids (n = 10) or provide usual care (n = 10). Of the 1,038 patients screened for severe hip or knee osteoarthritis, 581 were included in the study. Decision quality was similar between groups, with a score of 43 (36–51) in the intervention group and 44 (37–52) in the usual care group (RR 0.9, CI 0.7–1.2; P = 0.8), likewise, patient-experienced engagement assessed with CollaboRATE (RR 1.1, CI 0.8–1.4; P = 0.6). Consultations were longer in the intervention group, with a mean difference of 3.9 minutes (CI 0.1–7.7; P = 0.04). Conclusion: Decision quality and patient-reported engagement were similar between groups, while consultation time was longer with in-consult patient decision aids use. In the absence of prespecified minimal important differences, the clinical relevance of these findings remains uncertain.
Copyright (c) 2026 Trine Ahlmann Pedersen, Martin Lindberg-Larsen, Charlotte Myhre Jensen, Karina Dahl Steffensen, Claus Varnum https://creativecommons.org/licenses/by/4.0
Long-term implant retention after impacted elastic stable intramedullary nailing in pediatric diaphyseal forearm fractures: a retrospective cohort study
Background and purpose: In elastic stable intramedullary nailing (ESIN) for forearm fractures, nail protrusion may cause irritation-related implant removal. The primary aim was to evaluate implant retention after nail impaction, and secondarily to assess secondary procedures, complications, and protrusion as a predictor of removal. Methods: We analyzed a retrospective cohort of children with diaphyseal forearm fractures treated with impacted ESIN between 2017 and 2024. Implant retention was defined as no nail removal at record review. Secondary procedures were unplanned operations, while complications were adverse events managed conservatively. Radiographic nail protrusion was measured as extraosseous nail length and evaluated using receiver operating characteristic analysis to predict irritation-related implant removal. Results: 160 children with diaphyseal forearm fractures were included. At a mean observation time of 5 years, 132/160 children retained their implants (83%, 95% confidence interval [CI] 76–88). Secondary procedures occurred in 30/160 patients (19%, CI 13–26), most commonly irritation-related implant removal (10%, CI 6–16) and refracture (6%, CI 3–10). Complications occurred in 19/160 patients (12%, CI 7–18), including superficial radial nerve symptoms (7/160; 4.4%) and irritation without implant removal (6/160; 3.8%). A protrusion threshold of 3.3 mm predicted irritation-related implant removal (AUC 0.79, CI 0.71–0.86; sensitivity 100%, CI 83–100; specificity 55%, CI 49–61). No irritation-related removals occurred below this threshold. Conclusion: Impacted ESIN was associated with high long-term implant retention, although secondary procedures and complications occurred in about one-third of the patients. A protrusion threshold of 3 mm was linked to irritation-related removal and may guide implant retention.
Copyright (c) 2026 Jan Egil Brattgjerd, Christer Aasheim, Astrid Rosenberg, Christoffer Fotland, Vera Halvorsen https://creativecommons.org/licenses/by/4.0
Denosumab and bone loss in uncemented total hip arthroplasty: a secondary 5-year follow-up of a randomized controlled trial
Background and purpose: Denosumab may preserve periprosthetic bone mineral density (pBMD) around uncemented total hip arthroplasty (THA) components. This exploratory analysis of a previously published randomized controlled trial (RCT) aimed to assess the effects of denosumab on BMD 5 years after treatment cessation. Methods: 64 non-osteoporotic patients undergoing uncemented THA were enrolled in a randomized, double-blind, placebo-controlled phase-2 trial and received either 2 doses of denosumab or placebo. The primary outcome was pBMD at 12 months, measured by dual-energy X-ray absorptiometry (DEXA). At a mean follow-up of 5.6 years (range 4.3–7.3), 54 patients remained for clinical assessment, DEXA, and plain radiography. The study was registered on ClinicalTrials.gov (NCT01630941). Results: No differences in pBMD in the acetabular Digas zones or femoral Gruen zones were found between the groups at 5 years. The estimated mean difference in the sum of all zones around the cup was 0.042 g/cm² (95% confidence interval [CI] –0.31 to 0.35; P = 0.8), and for the sum of all Gruen zones –0.06 g/cm² (CI –0.55 to 0.43; P = 0.8). No statistically significant differences were observed in patient-reported outcome measures or the incidence of heterotopic ossification. A gradual decline in pBMD was evident. Conclusion: At 5 years, the adjusted between-group difference and its 95% confidence interval showed no statistically or clinically relevant effect of denosumab. Whether longer treatment duration or a sequential post-denosumab regimen could influence long-term periprosthetic bone preservation is unknown.
Copyright (c) 2026 Caroline Sköld, Nils P Hailer, Hans Mallmin https://creativecommons.org/licenses/by/4.0
Combating orthopedic implant biofilms — SABER (Study on Agitation for Biofilm Eradication and Reduction) evaluates mechanical, sonication, and radiofrequency approaches: a preclinical in vitro study
Background and purpose: Medical devices commonly employed in orthopedic surgery continue to be susceptible to challenging and costly biofilm bacterial infections. We aimed to evaluate the impact of mechanical brushing with sonication and radiofrequency on biofilms grown on 3 metallic alloys commonly utilized in orthopedic implants: titanium, stainless steel, and cobalt-chromium. Methods: Biofilms of 4 common bacteria encountered in orthopedic infections were grown on 540 metal chips for 3 metal alloy cohorts. The biofilms were treated with sterile saline irrigation, sonication brushing, or radiofrequency sonication brushing to compare against untreated control. Biofilm burden was evaluated both qualitatively and quantitatively with scanning electron microscopy imaging and crystal violet (CV) staining optical density or colony-forming unit measurements, respectively. Parametric, nonparametric, and linear regression analyses for quantitative data were performed. Results: Qualitatively and quantitatively, all interventions showed a strong reduction in biofilm burden of all microbes on all metals. There was a significant decrease in CV-stained biofilms for brushing interventions compared with irrigation alone and controls. Biofilm burden was significantly reduced in all experiments. The untreated control represented 100% biofilm. Irrigation alone reduced biofilm to 44%, while sonication further decreased biofilm to 25%. The most effective method, sonication with radiofrequency, reduced biofilm to 20%. Conclusion: Our data shows consistent qualitative and quantitative reduction in biofilm burden with brushing interventions compared with irrigation and control. While further study is warranted, our data suggest that mechanical brushing with sonication and radiofrequency may be beneficial tools in reducing biofilm burden on orthopedic metal implants.
Copyright (c) 2026 Timothy Greeley McManus, Michael W Fort, Kaitlyn E Barrack, Gabrielle S Ray, Michael B Sparks, Kevin J McGuire, George A O’TOOLE O'Toole https://creativecommons.org/licenses/by/4.0
National rates of pediatric extremity fractures over a 20-year timespan in Denmark: a population-based descriptive cohort study
Background and purpose: Previous reports on incidences rates of Scandinavian pediatric extremity fractures have varied, as they are often anatomically specific and based on institution-specific findings. To gain knowledge of current and future burden on the healthcare system, a national cohort assessment is necessary. We aimed to assess the proportion and incidence within anatomical distributions of pediatric extremity fractures in relation to age, sex, and time trends. Methods: We retrieved a 20-year population-based cohort from the Danish National Patient Registry 1999–2018. We included all children aged 0–15 years with an extremity fracture diagnosis (ICD-10). We estimated fracture proportions and incidence rates (IRs) in different anatomical regions stratified by sex, age groups, and periods. IRs were estimated based on national population counts. Results: We included 668,595 pediatric fractures corresponding to an overall IR of 3,164 (95% confidence interval 3,157–3,172) per 100,000 persons/year. The highest proportion and IR were in the lower arm, but the proportions differed within the age groups. The IR increased with age and was higher in boys. The overall IR increased during the study period. In upper and lower leg fractures a decrease was seen, with all other anatomical sites increasing. Conclusion: We found an increased IR during the study period for all fractures except for the upper and lower leg. The study gives important knowledge to the healthcare system when coordinating the right resources.
Copyright (c) 2026 Anja Rønnov Lund, Christian Færgemann, Per Gundtoft, Bjarke Viberg https://creativecommons.org/licenses/by/4.0
An Acta Orthopaedica educational article: Treatment of adult patients with a humeral shaft fracture
This educational review outlines the core principles of humeral shaft fracture (HSF) management and is designed for orthopedic trainees, general orthopedic surgeons, emergency physicians, and allied health professionals who participate in the acute or postoperative care of patients with HSFs. The content integrates the authors’ expert opinion with the current evidence. Humeral shaft fractures account for 1–3% of adult fractures, most often resulting from low-energy falls in older adults or high-energy trauma in younger patients. Although open fractures and neurovascular injuries are rare, primary radial nerve palsy (RNP) occurs in about 10% of cases. Diagnosis relies primarily on clinical evaluation and standard radiographs, with CT or MRI reserved for complex or pathological cases. Functional bracing has traditionally been the mainstay of nonsurgical treatment, achieving good long-term results but with nonunion rates up to 25%. Surgical fixation methods—including open reduction and internal fixation, minimally invasive plate osteosynthesis, and intramedullary nailing—allow earlier mobilization and more predictable fracture union but carry risks of iatrogenic RNP and infection. Management of primary RNP remains largely nonsurgical, with over 90% recovering spontaneously. Nonunion is frequently symptomatic and managed most often with compression plating. Surgery offers faster early recovery and lower nonunion rates, although long-term outcomes converge with successful bracing. Cost-effectiveness analyses suggest surgery may be more economical when productivity loss is considered, particularly for working-age patients. Optimal treatment selection depends on patient age, activity level, fracture characteristics, and patient preference, emphasizing shared decision-making.
Copyright (c) 2026 Thomas Ibounig, Olof Wolf, William M Oliver, Dennis Karimi, Bjarke Viberg, Maire Ratasvuori, Antti P Launonen, Tuomas Lähdeoja, Jeppe V Rasmussen, Lasse Rämö https://creativecommons.org/licenses/by/4.0
Machine learning and logistic regression in estimating survival in patients with high-malignant deep-seated soft tissue sarcomas: development and analysis based on a population-based retrospective cohort
Background and purpose: Soft tissue sarcomas are a heterogeneous group of malignant tumors with a high risk of metastasis, primarily to the lungs, making accurate survival prediction an essential part of long-term planning. No machine learning (ML) survival prediction models have been developed using a modern, population-based dataset from Scandinavia. We aimed to develop and compare ML models with logistic regression in predicting 5-year survival in soft tissue sarcoma patients and identify key predictive variables. Methods: This retrospective cohort study included patients diagnosed with deep-seated, high-grade soft tissue sarcomas of the extremities and trunk wall in Denmark from 2000 to 2016. Logistic regression was compared with 4 developed ML models, including random forest. Performance was assessed using the area under the curve (AUC), sensitivity, specificity, and calibration metrics, with a 70:30 training–test split and 5-fold cross-validation to evaluate the models. Results: 516 patients were included, of whom 226 (44%) died within 5 years following surgery. Random forest demonstrated the best ML performance on the training set and was compared with logistic regression on the test set. Logistic regression achieved an AUC of 0.74 (95% confidence interval [CI] 0.66–0.82), outperforming random forest‘s AUC of 0.65 (CI 0.56–0.74). Logistic regression also had higher sensitivity (0.65 vs 0.59) and specificity (0.72 vs 0.69), while random forest had a lower Brier score (0.38 vs 0.41). Conclusion: Although the developed random forest ML model performed well during training, logistic regression outperformed it after internal validation. Soft tissue sarcomas located in the trunk, grade 3 tumors, and chemotherapy within 3 months of surgery demonstrated the highest negative effect on survival, consistent with current treatment protocols in which patients with high-risk disease are managed with more aggressive multimodal therapy. Further external validation and assessment of clinical utility are required before potential clinical implementation.
Copyright (c) 2026 Andrea Thorn, Jessica A Lavery, Thomas Baad-Hansen, Jonathan A Forsberg, Michael Mørk Petersen, Christina Enciso Holm https://creativecommons.org/licenses/by/4.0
Assessing the value for money of a registry: an exploratory analysis of the Dutch Arthroplasty Register
Background and purpose: It is unclear whether arthroplasty registries provide value for money. We aimed to provide insight into this value for money by relating the costs of the Dutch Arthroplasty Register (LROI) to potential benefits from preventing revisions. Methods: We included all primary total hip (n = 276,252) and knee (n = 217,901) arthroplasties (THA/TKA), and all first revisions of these THAs (n = 8,604) and TKAs (n = 8,745) from the LROI between 2014 and 2022. Threshold analyses estimated at which number of prevented revisions the benefits (i.e., savings and increased quality of life) outweighed the LROI costs. Scenario analyses explored whether the required revision reductions were feasible, including the minimum revision reduction required per hospital, revision reduction at outlier hospitals only, and the potential impact of temporal changes in national 1-year revision rates. Results: The LROI costs were €5,697,120 for THA registration and €4,532,920 for TKA registration between 2014 and 2022. Preventing 119 to 145 THA revisions and 106 to 134 TKA revisions would be required in the current patient population over 30 years for the benefits to outweigh these LROI costs between 2014 and 2022, depending on revision costs. Each Dutch hospital should prevent 1.2 to 1.5 THA revisions and 1.1 to 1.3 TKA revisions to achieve the required revision reduction. Moreover, 306 THA revisions and 140 TKA revisions could be prevented if outlier hospitals improved their 1-year overall revision rate to the upper 99% control limit. Compared with the calendar years showing the highest revision rates, applying 2022 1-year revision rates to 2023 procedure volumes resulted in reductions of 1.5% for THAs and 0.3% for TKAs. Conclusion: Preventing approximately 1–2 revisions per hospital over 30 years would offset the LROI’s registration costs. Although causality cannot be established, these findings suggest that national arthroplasty registries may provide good value for money when actively used to reduce revision rates.
Copyright (c) 2026 Mirthe H W van Veghel, Gerjon Hannink, B Willem Schreurs, Janneke P C Grutters https://creativecommons.org/licenses/by/4.0
Patient satisfaction and patient-reported outcome measures after primary ankle arthrodesis: 2-year results from the Swedish Ankle Registry
Background and purpose: Ankle arthrodesis (AA) and total ankle replacement are the 2 main surgical treatment options for advanced ankle arthritis but information is scarce on satisfaction and patient-reported outcome measures (PROMs) after surgery. We aimed to evaluate postoperative satisfaction, changes in PROMs from before to 2 years after AA, and factors associated with the outcome. Methods: This is a national registry-based observational study using the Swedish Ankle Registry. We identified 1,145 patients who underwent AA between 2008 and 2020 who answered a question on satisfaction, and between 662 and 702 patients who answered pre- and 2-year postoperative PROMs (SElf reported Foot and Ankle Score [SEFAS], EQ-5D index, and EQ-5D VAS). We analyzed changes in scores and associations between surgical/patient factors (including preoperative PROMs) and the outcomes satisfaction/postoperative PROM score. Results: All mean PROM scores improved from before to 2 years postoperatively (all P < 0.001). 69% of the patients were satisfied with the procedure, 15% uncertain, and 16% dissatisfied. Satisfaction was associated with higher preoperative SEFAS score and dissatisfaction with lower preoperative SEFAS score. Higher SEFAS score was associated with male sex and osteoarthritis (compared with rheumatoid arthritis), while higher EQ-5D index and EQ-5D VAS scores were associated with male sex, posttraumatic arthritis, osteoarthritis (compared with rheumatoid arthritis), and higher age. Conclusion: The majority (69%) of patients treated with AA are satisfied with the procedure and a higher preoperative SEFAS score is associated with postoperative satisfaction. We speculate that preoperative SEFAS score may be useful for predicting postoperative outcomes and will facilitate preoperative patient discussions on expected results.
Copyright (c) 2026 Alexandra Undén, Lars Jehpsson, Anders Henricson, Magnus K Karlsson, Björn E Rosengren https://creativecommons.org/licenses/by/4.0
Associations between hospital characteristics, volume, and reasons for revision: a cohort study of 48,029 unicompartmental knee arthroplasties with 3,397 revisions from the Dutch Arthroplasty Register
Background and purpose: It remains debated whether high annual hospital volumes for unicompartmental knee arthroplasty (UKA) are associated with a low risk of revision, and what explanations may underlie this relationship. We aimed to analyze the association between specific hospital characteristics defined as volume, type, and referral for revision, and frequency and reasons for UKA revision. Methods: Data from primary UKAs (2007–2022) and their revisions were extracted from the Dutch Arthroplasty Register. Hospitals were categorized by type; academic, top clinical teaching, private, or other general hospitals. Hospitals were grouped by annual UKA volume: ≤24, 25–39, 40–79, and ≥80 procedures. Multiple linear regression assessed the relationship between the number of revisions with hospital volume and type, adjusted for confounders. Chi-squared tests were used to test for differences in revision reasons based on volume and referrals. Results: 48,029 primary UKAs and 3,397 revisions were included. High-volume and top clinical teaching hospitals had a significantly lower risk of revision following primary UKA (P < 0.001). Cementless implants had a lower risk compared with cemented implants. Revision reasons varied by hospital volume and whether revision occurred after referral (P < 0.001). Loosening, progression of osteoarthritis, malalignment, and pain were less common in the highest volume hospitals. If revision occurred after referral, malalignment was more frequently registered as the reason for revision. Conclusion: High-volume and top clinical teaching hospitals were associated with lower risk of revision following primary UKA. Differences in revision reasons, with fewer cases of loosening, progression of osteoarthritis, malalignment, and pain, may explain the lower risk of revision at higher volume hospitals.
Copyright (c) 2026 Hendrik W.H. de Raadt, Iris Koenraadt-van Oost, Anouk Nijs, Anneke Spekenbrink-Spooren, Leon Elmans, Rutger C I van Geenen https://creativecommons.org/licenses/by/4.0
Postoperative mobility is associated with risk of reoperation and increased mortality after hip fracture: a nationwide cohort study of 33,486 patients
Background and purpose: Postoperative mobilization may influence the outcome following hip fracture. We aimed to examine whether regaining pre-fracture basic mobility on discharge is associated with subsequent risk of reoperation and mortality. Methods: Using nationwide Danish registries, we identified 33,486 patients ≥ 65 years who underwent hip fracture surgery between January 2016 and November 2021. Pre-fracture and discharge mobility were assessed with the Cumulated Ambulation Score (CAS, score 0–6 where 6 is best ambulation). The exposure was regaining pre-fracture CAS at discharge. Adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for reoperation and mortality up to 365 days were estimated using Cox regression, adjusting for age, sex, surgery year, length of stay, and comorbidities. Results: On discharge, 19,329 patients (65%) had not regained pre-fracture CAS. The 30-day reoperation risk was similar among patients who had not regained CAS (2.9%) and those who had (2.5%; aHR 1.10, CI 0.94–1.29). At 365 days, not regaining CAS was associated with a lower reoperation risk (7.1% vs 8.6%; aHR 0.98, CI 0.89–1.07). A CAS loss of 1–2 points was associated with an increased 30-day reoperation risk (aHR 1.20, CI 1.00–1.44). CAS decline was consistently associated with higher mortality at 30 days (aHR 2.07, CI 1.82–2.35) and 365 days (aHR 1.77, CI 1.66–1.89), with progressively higher rates at greater CAS decline. Conclusion: We found no consistent association between failure to regain pre-fracture mobility on discharge and reoperation, although patients with a 1–2 point CAS loss experienced a modestly higher 30-day reoperation risk. In contrast, failure to regain pre-fracture mobility was strongly associated with increased mortality up to 1 year after hip fracture.
Copyright (c) 2026 Simon Storgaard Jensen, Per Hviid Gundtoft, Jan-Erik Gjertsen, Alma B Pedersen https://creativecommons.org/licenses/by/4.0
Movement of the sacroiliac joint during a modified active straight leg raise measured with CT-RSA: a feasibility study
Copyright (c) 2026 Vinjar Brenna Hansen, Anselm Schulz, Christian Hellum, Stephan M Röhrl https://creativecommons.org/licenses/by/4.0
Surgical and nonsurgical treatment of hip and knee osteoarthritis: a 2026 perspective
Copyright (c) 2026 Jens Holm Laigaard, Tazio Maleitzke, Søren T Skou, Inger Mechlenburg, Thomas Bandholm, Lise C Berg, Søren Overgaard https://creativecommons.org/licenses/by/4.0
Inducible displacement CT for implant loosening detection: a scoping review on methods, validation, and challenges
Background and purpose: Inducible displacement CT (ID-CT) is an emerging method for diagnosing implant loosening by (i) acquiring CT scans under different joint loading conditions, (ii) analyzing scans via segmentation and registration, and (iii) quantifying and visualizing relative implant–bone displacement. With multiple centers approaching these steps differently, this scoping review aimed to summarize current methodologies and key challenges. Methods: PubMed, Cochrane, and Embase were searched for clinical and experimental ID-CT studies on spinal and arthroplasty implants. Data was extracted using a table based on updated CT-radiostereometric analysis (RSA) guidelines, including study characteristics, CT acquisition parameters, image analysis methods, validation approaches, outcomes, and loading protocols. Diagnostic studies were assessed with QUADAS-2. Results: 22 studies were included concerning the hip (10), knee (7), spine (4), and wrist (1), covering clinical and experimental (phantom and cadaveric) designs. Loading protocols varied widely, applying compressive, rotational, and angular forces with external stabilization or loading devices. CT acquisition ranged from µCT to conventional and weight-bearing CT, with variation in kVp, mAs, reconstruction spacing, and metal artefact reduction. Image-analysis workflows were broadly similar, though reporting of algorithms and displacement metrics was often incomplete. Diagnostic validation was limited by variable reference standards, non-prespecified loosening thresholds, and non-blinded assessments, undermining true performance. Technical validation, although often precise, did not cover the full ID-CT pipeline (i.e., complete loading protocol), leaving key sources of measurement variance untested. Conclusion: We showed that ID-CT is used with a wide variation in approach and limited reporting prevents the establishment of its true diagnostic accuracy.
Copyright (c) 2026 Maaike A ter Wee, Johannes G G Dobbe, Arthur J Kievit, Matthias U Schafroth, Mario Maas, Leendert Blankevoort, Geert J Streekstra https://creativecommons.org/licenses/by/4.0
Outcomes of hip reconstruction in ambulatory patients with cerebral palsy and spastic hip displacement: a retrospective study of 73 hips in 55 consecutive patients
Background and purpose: Currently, there is no specific surgical treatment strategy established for spastic hip displacement in ambulatory patients with cerebral palsy. We aimed to evaluate the outcomes of our hip reconstructions, specifically designed to address hip displacement within the context of single-event multilevel surgery (SEMLS). Methods: We conducted a retrospective study on patients with Gross Motor Function Classification System (GMFCS) levels II (n = 27) and III (n = 28). Surgical procedures involved various combinations of open or closed reduction, iliac osteotomy, proximal femoral derotational osteotomy, distal femoral derotational and shortening osteotomy, and proximal femoral varus derotational osteotomy. The overall developmental status of the hip was assessed using the Melbourne Cerebral Palsy Hip Classification Scale (MCPHCS) at a mean age of 17.3 years (SD 4.7). Results: 73 hips in 55 patients were included. They underwent hip reconstruction at a mean age of 9.7 years (SD 2.6). 69 of 73 hips achieved successful outcomes. Before surgery, 51 hips had a migration percentage (MP) of 30–60%, 21 had 60–100%, and 1 hip > 100%. At the final follow-up, 12 hips were classified as MCPHCS grade 1 (MP < 10%), 36 as grade 2 (10–15%), 21 as grade 3 (15–30%), 3 as grade 4 (30–60%), and 1 as grade 5 (60–100%). 52 patients either maintained or improved their preoperative GMFCS levels. Conclusion: Within the SEMLS framework, our tailored hip reconstruction achieved satisfactory hip outcomes in 69 of 73 hips and resulted in sustained improvement in hip stability at long-term follow-up.
Copyright (c) 2026 Kyeong Hyeon Park, Byoung Kyu Park, Isaac Rhee, Kun Bo Park, Hoon Park, Yun Ho Roh, Hyun Woo Kim https://creativecommons.org/licenses/by/4.0
Bony adaptation signs are predictive of anterior head–neck offset remodeling after internal fixation for slipped capital femoral epiphysis: a multicenter study on 217 patients (228 hips) with follow-up until end of growth
Background and purpose: We aimed to evaluate the prognostic value of radiographic factors in predicting femoral head–neck remodeling, cam deformity, and local growth disturbances in slipped capital femoral epiphysis (SCFE) treated with internal fixation (IF) with or without simultaneous closed reduction. Methods: A retrospective multicenter study on 217 SCFE patients (228 hips) treated with IF in 10 institutions was performed. Hip morphology was assessed using preoperative, postoperative, and end of growth (EG) radiographs and radial MRI scans. Evaluated parameters included: epi-metaphyseal distance, Southwick angle (SA), head–neck offset (HNO), femoral neck varus deformity, and shortening. Depending on the presence of bony adaptation (BA; defined as rounded anterior metaphyseal edge and posterior callus formation, typically indicating slip onset > 4 weeks) at diagnosis hips were divided into Group A (n = 96; without BA) and Group B (n = 132; with BA). Results: At EG, Group A demonstrated better slip correction, more favorable femoral neck remodeling, and lower risk of residual cam deformity than Group B (15% vs 58%, risk difference –43%, 95% confidence interval –54 to –32). Remodeling occurred in most cases in both groups, but normal values were not uniformly reached. Femoral neck varus deformity and shortening were observed in both groups and attributed to disease-specific growth plate damage rather than transphyseal fixation. Conclusion: Radiographic signs of BA at diagnosis can predict the risk of cam deformity at EG. Cases without BA have a favorable prognosis, whereas slips with BA have a higher risk of residual deformity. Signs of BA demonstrated a higher predictive value (0.84) than SA > 40° (0.60) or negative HNO < –5 mm (0.57).
Copyright (c) 2026 Fritz Hefti, Katharina Oder, Renata Pospischill, Bernd Bittersohl, Kathrin Lehnert, Marco Goetze, Danimir Cerkez, Kiril Mladenov, Bjoern Vogt https://creativecommons.org/licenses/by/4.0
Similar incidence and implant survival of multiply revised knee arthroplasties in Norway and Denmark: a register study of the Danish and Norwegian Knee Arthroplasty registries from 1998–2021
Background and purpose: The aim of our study was to identify the absolute incidence and implant survival probability of multiply revised knee arthroplasties in Norway and Denmark from 1998 to 2021. Methods: This was an observational study of primary and revision knee arthroplasties reported prospectively in Norway and Denmark. The nationwide registers in Norway and Denmark were utilized. After identification of all primary procedures reported from 1998 to 2021, revision procedures were identified. Probabilities of implant survival were calculated using Kaplan–Meier methods. A multiply revised knee arthroplasty was defined as at least 3 revisions of a primary knee arthroplasty. Results: The proportion of third revisions was 0.4% in both Denmark (621/159,343) and Norway (404/105,192). The 16-year implant survival of third revisions was 57% (CI 52–62) in Denmark and 54% (CI 48–61) in Norway. No difference in the risk of revision between countries was found for the third revision (HR 1.1, CI 0.7–1.8). Conclusion: The incidence of multiply revised knee arthroplasties was not significantly different between Norway and Denmark. The risk and implant survival probability of multiply revised knee arthroplasties was similar in the 2 countries. The results can be used as a benchmark for incidence and prevalence calculations in other countries.
Copyright (c) 2026 Julius Tetens Hald, Anne Marie Fenstad, Anders El-Galaly, Anders Odgaard, Ove Nord Furnes https://creativecommons.org/licenses/by/4.0
Incidence proportion of complex regional pain syndrome (CRPS) after distal radius fracture: a population-based register study
Background and purpose: One of the most severe complications of distal radius fractures (DRF) is the development of complex regional pain syndrome (CRPS). The incidence proportion (IP) of CRPS following DRF varies widely in the literature. Our aim is to report the incidence proportion of CRPS in DRF patients, subgrouping on age, sex, and treatment choice, and secondarily to assess development over time. Methods: Data was extracted from the Danish National Patient Register on patients > 18 years diagnosed with a DRF (S525) in the period 1998–2017. Results: There were 247,128 DRF in 203,533 patients with a mean age of 61 years. 75% were females. Within 1 year, 493 DRF patients developed CRPS corresponding to a 1-year IP of 0.20% and with an incidence density of 0.57/100,000/year. Median time from DRF to diagnosis was 89 days (SD 73). The IP ranged from 0.01% to 0.39% between age groups with the 30–65-year-olds having the highest incidence proportion. The surgically treated group had an IP of 0.31% and the non-surgical group had an IP of 0.17%. CRPS was slightly more common in women than men (0.21% vs 0.16%). We found a decrease in IP after 2010 from 0.24% to 0.14%. Conclusion: There was a low IP of CRPS diagnosis after DRF treatment with an observed higher IP in the 30–65-year-olds and in surgically treated patients. We consider this to be a minimum IP due to possible undiagnosed cases, but the overall results may be closer to the clinical reality than previous studies.
Copyright (c) 2026 Pernille Melbye, That Minh Pham, Niels-Peter Brøchner Nygaard, Carsten Hanshelge Kock-Jensen, Per Hviid Gundtoft, Bjarke Viberg https://creativecommons.org/licenses/by/4.0
Update of guideline for diagnosis and treatment of subacromial pain syndrome: a multidisciplinary review by the Dutch Orthopedic Association Part 2: Operative considerations and treatment of various conditions related to subacromial pain syndrome
Background and purpose: In 2013, the first clinical practice guideline for subacromial pain syndrome (SAPS) was developed in the Netherlands to support healthcare professionals. SAPS refers to non-traumatic, non-rheumatologic shoulder complaints that are particularly painful during arm elevation. It includes conditions such as supraspinatus tendinosis, calcific tendinitis, and degenerative supraspinatus tears. Over 50,000 patients annually consult orthopedic surgeons for these issues. In response to new evidence and clinical needs, an updated guideline was developed. Part 2 focuses on supraspinatus tears, biceps tendon pathology, and calcific tendinosis. Using a multidisciplinary, evidence-based approach, the guideline aims to answer key clinical questions around SAPS. Methods: Initiated by the Dutch Orthopedic Society, the guideline committee identified knowledge gaps through group sessions. Each module was based on a PICO-formatted key question and reviewed by professionals from different fields. The AGREE and GRADE methods were applied to ensure a systematic evaluation of evidence, leading to conclusions and recommendations. Results: (i) Start with exercise-based therapy (with corticosteroid injection) for isolated, symptomatic, non-traumatic supraspinatus tears. Consider cuff repair if no improvement after 3–6 months. (ii) Avoid biceps tenotomy/tenodesis on a healthy tendon unless at risk during cuff repair. (iii) Evaluate patient- and tear-specific factors; use MRI for detailed assessment. (iv) Consider barbotage for calcific tendinosis; repeat once if needed. Reserve surgery for persistent large calcifications. (v) Postoperative immobilization should not exceed 3 weeks. Conclusion: The updated guideline provides multidisciplinary recommendations for surgical management.
Copyright (c) 2026 Frederik O Lambers Heerspink, Egbert J D Veen, Oscar Dorrestijn, Cornelis P J Visser, Maarten J C Leijs, Dennis van Poppel, Peter A Stroomberg, Ramon P G Ottenheijm, Jan W Kallewaard, Tjerk J W de Ruiter, Henk A Martens, Femke M Janssen, Tessa Geltink, Matthijs S Ruiter, Jos J A M van Raaij https://creativecommons.org/licenses/by/4.0
Update of guideline for diagnosis and treatment of subacromial pain syndrome: a multidisciplinary review by the Dutch Orthopedic Association Part 1: preventive measures, diagnostics, and non-surgical treatment of subacromial pain syndrome
Background and purpose: In 2013, the first clinical practice guideline for subacromial pain syndrome (SAPS) was developed in the Netherlands to support healthcare professionals. SAPS refers to non-traumatic, non-rheumatologic shoulder complaints that are particularly painful during arm elevation. It includes conditions such as supraspinatus tendinosis, calcific tendinitis, and degenerative supraspinatus tears. Over 50,000 patients annually consult orthopedic surgeons for these issues. In response to new evidence and clinical needs, an updated guideline was developed. Part 1 addresses prevention, diagnosis, imaging, and non-surgical treatment. Using a multidisciplinary, evidence-based approach, the guideline aims to answer key clinical questions around SAPS. Methods: Initiated by the Dutch Orthopedic Society, the guideline committee identified knowledge gaps through group sessions. Each module was based on a PICO-formatted key question and reviewed by professionals from different fields. The AGREE and GRADE methods were applied to ensure a systematic evaluation of evidence, leading to conclusions and recommendations. Results: (i) Inform patients about the potential positive effects of a healthy lifestyle and encourage gradual exercise within sport and work. (ii) Perform a cluster of physical diagnostic tests to diagnose SAPS. (iii) Perform ultrasonography in patients with clinical suspicion of (partial thickness) rupture of the supraspinatus tendon. Consider MRI if ultrasound is not available or inconclusive. (iv) Consider barbotage for symptomatic calcific tendinosis, preferably with corticosteroid injection in the bursa, if a previous corticosteroid injection was ineffective. (v) Consider a subacromial corticosteroid injection (with a local anesthetic) to enable exercise therapy in patients with severe complaints that impair their ability to participate in exercise therapy. (vi) Consider suprascapular nerve block for patients with therapy-resistant SAPS when other non-surgical treatment is ineffective. Conclusion: The updated guideline provides multidisciplinary recommendations for physical examination, imaging, and conservative management of SAPS.
Return to work following traumatic fractures of the thoracolumbar spine without spinal cord injury: a scoping review
Background and purpose: Traumatic fractures of the thoracolumbar spine happen in the younger, working-age population and often compromise return to work (RTW), a key factor in functional recovery and overall quality of life. Our review summarizes the current evidence on RTW following traumatic thoracolumbar fractures without spinal cord injury. Methods: A comprehensive literature search was conducted in Embase, Medline (OvidSP), Web of Science, CINAHL and Cochrane through July 2025. Studies were included if they met the following criteria: (i) traumatic thoracolumbar spine fracture without spinal cord injury, (ii) RTW reported as an outcome measure, (iii) prospective or retrospective cohort study or case-control design, and (iv) availability of a full-text article. Risk of bias was assessed for each included study. Results: 31 studies met the inclusion criteria. Follow-up ranged from 3 to 226 months. Only 8 out of 31 studies were rated as low risk of bias. Reported RTW rates varied widely: 25% to 100% after surgical treatment (n = 19 studies) and 38% to 100% after non-surgical treatment (n = 19 studies). Pooled estimates showed that the mean RTW is between 76% and 84% in patients with a thoracolumbar spine fracture, irrespective of treatment modality. Conclusion: Estimated RTW rates range between 76% and 84%.
Copyright (c) 2026 Mathijs Suijkerbuijk, Daan Cranenbroek, Sara I van Ameijden, Pim W van Egmond , Margot C W Joosen, Mariska A C de Jongh, Ruth E Geuze https://creativecommons.org/licenses/by/4.0
The long-term revision risk of RSA-tested and non-RSA-tested TKA implants in The Netherlands: a Dutch arthroplasty register study
Background and purpose: Radiostereometric analysis (RSA) of total knee arthroplasty (TKA) is used as an early safeguard during the phased evidence-based introduction of new implants. The goal of our study was to compare the long-term revision risk between RSA-tested implants and non-RSA-tested implants in the Netherlands using patient-level data. Methods: All primary TKAs between 2007 and 2016 from the Dutch Arthroplasty Register were included, and procedures with an RSA-tested implant were identified. Both all-cause major revision risk and revision risk because of loosening were calculated at 5 and 10 years postoperatively using Kaplan–Meier analyses. Sensitivity analyses were performed with stricter definitions of implant characteristics to classify procedures as RSA-tested, to avoid camouflage of different subdesigns within the same brand implant portfolio. Results: 83,638 RSA-tested and 104,105 non-RSA-tested TKAs were included. Cumulative all-cause major revision percentages for the RSA-tested group at 5 and 10 years were 2.2% (95% confidence interval [CI] 2.1–2.3) and 3.6% (CI 3.4–3.7), respectively, compared with 2.5% (CI 2.4–2.6) and 3.3% (CI 3.2–3.4) for the non-RSA-tested group. RSA-tested TKAs showed higher 10-year revision risks because of loosening than non-RSA-tested procedures (1.8%, CI 1.7–1.9 vs 1.4%, CI 1.3–1.4, respectively). Comparable results were found after stratification by various patient characteristics and with stricter classification approaches. Conclusion: Regarding all-cause revision risk, RSA-tested TKAs had a slightly lower risk at 5 years. However, at 10 years the RSA-tested TKAs had a higher all-cause revision risk and higher revision risk because of loosening compared with the non-RSA-tested TKAs.
Copyright (c) 2026 Thies J N van der Lelij, Bart G Pijls, Bart L Kaptein, Liza N van Steenbergen, Rob G H H Nelissen, Perla J Marang-van de Mheen https://creativecommons.org/licenses/by/4.0
Outcomes after reoperated medial unicompartmental knee arthroplasties compared with primary total and primary unicompartmental knee arthroplasties: a cohort study based on local Danish databases
Background and purpose: Tibial periprosthetic fractures (PPF), periprosthetic joint infections (PJI), and bearing dislocations (BD) are among the most common short-term complications in medial unicompartmental knee arthroplasty (mUKA). We aim to assess whether patients with these complications have patient-reported outcome measures (PROMs) that differ from patients with primary mUKA, primary total knee arthroplasty (TKA), or after revision TKA . Methods: This observational study included 74 mUKA patients reoperated for PPF (n = 22), PJI (n = 15), or BD (n =3 7) between January 2018 and January 2023. Comparator groups included 1,940 primary mUKA, 3,485 primary TKA, and 350 reoperated TKA patients. The primary endpoint was Oxford Knee Score (OKS) at 12 months. Missing data was imputed, and multilevel Tobit regression was used to analyze differences in PROMs. Results: At 12 months, reoperated mUKAs had lower PROM scores than primary mUKAs (OKS difference –3.3, 95% confidence interval [CI] –5.0 to –1.5) and TKAs (OKS difference –2.7, CI –4.4 to –0.9) but higher than reoperated TKAs (OKS difference: 3.0, CI 1.1 to 5.0). PPF mUKAs had 12-month scores resembling reoperated TKAs (OKS difference –0.7, CI –3.9 to 2.5). PJI mUKAs and BD mUKAs had 12-month scores resembling primary mUKAs (PJI: OKS difference –2.4, CI –6.2 to 1.5, BD: OKS difference –2.2, CI –4.7 to 0.2) and primary TKAs (PJI: OKS difference –1.7, CI –5.6 to 2.1, BD: OKS-difference –1.6, CI –4.1 to 0.8). Conclusion: Patients reoperated for PJI and BD achieved outcomes comparable to primary mUKAs and TKAs, while PPF resulted in scores lower than primary mUKAs and TKAs, comparable to reoperated TKAs.
Copyright (c) 2026 Christian Bredgaard Jensen, Claus Varnum, Simon Kornvig, Kristine Ifigenia Bunyoz, Kirill Gromov, Anders Troelsen https://creativecommons.org/licenses/by/4.0
Association of acetabular implants with sensitive radiographic surveillance on revision rates: a study based on 5 hip arthroplasty registries
Background and purpose: National joint arthroplasty registries are the gold standard for monitoring long-term acetabular implant survivorship. Sensitive radiographic surveillance (SRS) has been recommended as a complementary surveillance approach, but no study has investigated whether implants introduced with no sensitive radiographic surveillance (NSRS) are associated with higher revision rates. Therefore, we investigated whether acetabular implants with NSRS are associated with higher revision rates than those with SRS. Methods: Acetabular implants with SRS were defined as those with published evidence of stability measurements assessed using either radiostereometric analysis or “Ein Bild Röntgen Analyse.” Evidence of SRS of acetabular implant designs was sourced from 2 literature reviews. A mixed-effects model was used to pool and compare the revision rate of acetabular implants with SRS and NSRS at 5 and 10 years from 5 arthroplasty registries. Results: There were 29 unique acetabular implant designs with SRS and 86 designs with NSRS that had matching 5- and 10-year revision rates. At 5 years, there was a mean difference of 0.8% (95% confidence interval [CI] 0.5–1.1) in mean all-cause revision rates favoring implants with SRS. Mean all-cause revision rates at 10 years for acetabular implants with SRS and NSRS were 5.2% (CI 4.9–5.5) and 7.4% (CI 7.0–7.9) respectively, with a mean difference of 1.8% (CI 1.2–2.3) favoring implants with SRS. Conclusion: Acetabular implants with NSRS were associated with 1.8% higher pooled revision rates than those with SRS at 10 years, which represents a relative increase in acetabular revision burden of approximately 36%.
Copyright (c) 2026 Chan Hee Cho, John M Abrahams, Deepti K Sharma, Lucian B Solomon, Christopher J Wall, Bart G Pijls, Stuart A Callary https://creativecommons.org/licenses/by/4.0
The risk of revision using tourniquet or not in primary total knee replacement: an observational study from the Swedish Knee Arthroplasty Register
Background and purpose: The use of a tourniquet in knee replacement surgery is debated. Given the conflicting evidence, we aimed to compare the risk of revision after total knee replacements (TKR) with or without the use of tourniquet. Methods: In this register based observational study, we included the 5 most common cemented primary TKR models due to osteoarthritis reported to the Swedish Arthroplasty Register 2010–2024 and followed them until December 31, 2024. The first revision for implant loosening was the primary outcome. We estimated the cumulative revision rate (CRR) with 95% confidence interval (CI) using the 1–Kaplan–Meier method. We examined the use of a tourniquet regarding the risk of revision using multiple Cox regression analysis to calculate the hazard ratio (HR) with CI and adjusted for potential confounding factors. Results: Of the 149,616 TKRs included, 65,570 (44%) were with tourniquet and 84,046 (56%) without tourniquet. The CRR was similar at all time-points for all causes and infection; however, CRR started to increase at 6–7 years for implant loosening with use of a tourniquet. In the Cox regression analysis, the use of a. tourniquet was associated with an increased risk of revision for implant loosening after 5 years (HR 1.56, CI 1.06–2.30). There was no difference in revision for all causes (HR 1.07, CI 0.99–1.15) or infection (HR 1.08, CI 0.97–1.21). Conclusion: The use of a tourniquet was associated with an increased risk of revision for implant loosening after 5 years, while no association was found for all-cause revision or infection. Our results do not support the use of a tourniquet in TKR as a strategy to reduce the risk of revision, either due to all causes, implant loosening, or infection.
Copyright (c) 2026 Annette W-Dahl, Johan Kärrholm, Perna Ighani Arani, Ola Rolfson https://creativecommons.org/licenses/by/4.0
Perspective: Fragility Fracture Network in the Nordic Orthopaedic Federations countries – the role of orthopaedic surgeons
Copyright (c) 2026 Alma B Pedersen, Frede Frihagen, Lene B Solberg, Peter van den Berg, Marsha van Oostwaard, Johanna Rundgren, Karl-Åke Jansson, Henrik Palm https://creativecommons.org/licenses/by/4.0
Patient-reported outcomes following patellofemoral and total knee replacement: an analysis of the 6–18 months postoperative period from the National Joint Registry
Background and purpose: Patellofemoral joint replacements (PFR) and total knee replacements (TKR) are surgical treatment options for patellofemoral joint osteoarthritis. We aimed to compare patient-reported outcome measures (PROMs) for these procedures, and revision thresholds for PFR. Methods: Data from the National Joint Registry (2009–2021) was linked with the Hospital Episodes Statistics (HES) database. Data was then merged with the PROMs dataset and adjusted using inverse proportional treatment weighting methods. Primary PROMS were Oxford Knee Score (OKS) and EQ5D-3L at the 6–18-month mark with a minimal clinically important difference of 5 for OKS. Secondary outcome measures included threshold to revision, defined as the cut-off score at which an arthroplasty was revised. Differences in patient characteristics between those classed as best and worst outcomes were compared and regression analyses examined the influence of factors such as age, provider type (public or private healthcare), and comorbidities on PROMs with results stratified by sex. Results: 340,449 matched records were analyzed (1,085 PFR, 339,364 TKR). The median postoperative OKS was 35 (PFR) and 38 (TKR), with a difference of –2.4. Patients with the best PFR outcomes were older (62.0 vs 57.2 years, P = 0.01). The median 6-month EQ5D-3L was 0.77 (PFR) and 0.80 (TKR). PFR had a higher revision hazard ratio (3.4, 95% confidence interval 2.7–4.4, P = 0.01), indicating a lower threshold for revision. Conclusion: Up to 18 months, in terms of OKS and EQ5D-3L, there was no significant difference between the 2 procedures. PFR had a lower threshold for revision compared with TKR. Future research should incorporate more objective measures, such as activity level, where objective differences might be identified.
Copyright (c) 2026 Martinique Vella-baldacchino, Alex Bottle, Justin Cobb, Alexander D Liddle https://creativecommons.org/licenses/by/4.0
Complication rates following open surgical removal of osteosynthesis material from the pelvis and acetabulum: a retrospective case series of 154 removals
Background and purpose: While complication rates for primary pelvic and acetabular fracture surgeries are well documented, limited data exists on complications following osteosynthesis implant removals. We aimed to evaluate the complication rates of pelvic implant removals with respect to the surgical approach, type of implant, and indication for removal. Methods: This retrospective, consecutive case series included all patients undergoing pelvic implant removal between January 2013 and December 2023 using Kocher-Langenbeck, modified Stoppa (AIP), or ilioinguinal approaches for the removal. Isolated minimally invasive, percutaneous implant removals were excluded. Results: 154 implant removals in 141 patients were analyzed. Overall complication rate was 34% (n = 53). Most common complications were intraoperative bleeding requiring transfusion (n = 17; 11%), postoperative anemia requiring transfusion (n = 12; 7.8%), and vascular injuries (n = 9; 5.8%). The ilioinguinal approach showed a higher complication rate (19/37; 51%) than the Kocher-Langenbeck (21/68; 31%) or the Stoppa/AIP approach (13/49; 27%). Removal of implants from the anterior pelvic ring and acetabulum (22/45; 49%) also had a higher complication risk than from the posterior pelvic ring and acetabulum (20/67; 30%) or of symphyseal plates (11/42; 26%). Removal due to infection also showed a particularly high complication rate (25/57; 44%) compared with aseptic indications, e.g., interfering material or removal for THA. Conclusion: Pelvic implant removals, especially from the anterior pelvic ring or acetabulum, using the ilioinguinal approach, and in case of infection, are associated with a particularly high complication risk. These findings can support clinical decision-making and informing patients on the potential risks of hardware removals.
Copyright (c) 2026 Thore C Scherff, Nico Hinz, Cornelius Grimme, Karl-Heinz Frosch, Maximilian Hartel https://creativecommons.org/licenses/by/4.0
Association of antioxidant-added highly cross-linked polyethylene on revision risk: a registry-based study of 198,073 total hip replacements from the Australian Orthopaedic Association National Joint Replacement Registry between 2014 and 2023
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.
Copyright (c) 2026 Peter L Lewis, David G Campbell, Peiyao Du, Helena Oakey, Richard N de Steiger, Paul N Smith https://creativecommons.org/licenses/by/4.0
Changing trends in the management of pediatric distal forearm fractures: a descriptive Danish 20-year nationwide registry study of 175,083 cases
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.
Copyright (c) 2026 Katrine Rønn Abildgaard, Per Hviid Gundtoft, Stig Brorson, Bjarke Viberg https://creativecommons.org/licenses/by/4.0
Survivorship and risk factors for revision after total hip arthroplasty in patients 30 years and younger: a cohort study from the German arthroplasty register
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.
Copyright (c) 2026 Johanna Elliott, Yinan Wu, Arnd Steinbrück, Alexander W Grimberg https://creativecommons.org/licenses/by/4.0
Correlation between acetabular index at 3 and 12 months of age: a longitudinal radiographic study of 228 neonates treated for 6 or 12 weeks with the von Rosen splint for developmental dysplasia of the hip
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.
Migration in unicompartmental knee arthroplasty with the Persona Partial Knee: a cohort study of 26 patients using radiostereometry with 60 months of follow-up
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.
Copyright (c) 2026 Jantsje H Pasma, Brechtje Hesseling, Nicole de Esch, Hennie Verburg, Dieu D Niesten, Nina M C Mathijssen https://creativecommons.org/licenses/by/4.0