Background and purpose — Partial knee replacement (PKR) survival rates vary a great deal among registries and cohort studies. These discrepancies can largely be attributed to inappropriate indications of the PKR and low thresholds for revision, but also to the PKR volume. This study used Dutch Arthroplasty Register data to analyze whether absolute PKR or proportional PKR hospital volume is associated with the risk of revision. Patients and methods — 18,134 PKRs were identified in the Dutch Arthroplasty Register from 2007 to 2016. For each year, hospitals were divided into 4 groups based on the quartiles for the absolute volume (< 22, 22–36, 36–58 and > 58 PKRs per year) and the proportional volume (< 8.5, 8.6–14.2, 14.3–25.8 and > 25.8% PKRs). Kaplan–Meier survival analysis was performed to determine survival rates. A multivariable Cox regression adjusted for age category, sex, ASA score, year of surgery, diagnosis, unicondylar side, and type of hospital was used to estimate hazard ratios (HR) for revision. Results and interpretation — Proportional PKR volume did not, but absolute PKR volume did influence the risk of revision. The adjusted HR for hospitals with an absolute volume of 22–36 PKRs per year was 1.04 (95% CI 0.91–1.20), 0.96 (CI 0.83–1.10) for the hospitals with 36–58 PKRs, and 0.74 (CI 0.62–0.89) for hospitals with more than 58 PKRs compared with hospitals that had fewer than 22 PKRs per year. So, patients treated with a PKR in a high absolute volume hospital have a lower risk of revision compared with those treated in a low absolute volume hospital. One of the advantages of partial knee replacement (PKR) is that the native mechanics of the knee are largely preserved, whereas in total knee replacement (TKR) the anterior cruciate ligament is sacrificed and the mechanics change substantially (Laurencin et al. 1991 ). This might contribute to better a postoperative clinical outcome following PKR compared with TKR (Liddle et al. 2015 ). Also, a lower risk of complications has been reported for PKR (Liddle et al. 2014a , Beard et al. 2019). Furthermore, a recent randomized trial demonstrated similar Oxford Knee Scores, a higher perceived knee improvement, higher willingness to undergo the operation again, and better cost-effectiveness after PKR compared with TKR at 5 years’ follow-up (Beard et al. 2019). Nevertheless, since its introduction, the PKR has been a topic of debate due to the diversity in reported long-term survival rates.

Children often present at the emergency department with a suspected elbow fracture. Sometimes, the only radiological finding is a ‘fat pad sign’ (FPS) as a result of hydrops or haemarthros. This sign could either be the result of a fracture, or be due to an intra-articular haematoma without a concomitant fracture. There are no uniform treatment guidelines for this common population. The aims of this study were (1) to obtain insight into FPS definition, diagnosis, and treatment amongst international colleagues, and (2) to identify a uniform definition based on radiographic measurements with optimal cut-off points via a receiver operating characteristic (ROC) curve. An online international survey was set up to assess the diagnostic and treatment strategies, criteria, and definitions of the FPS, the probability of an occult fracture, and the presence of an anterior and/or posterior FPS on 20 radiographs. Additionally, the research team performed radiographic measurements to identify cut-off values for a positive FPS, as well as test–retest reliability and inter-rater reliability via intraclass correlation coefficients (ICC). A total of 133 (paediatric) orthopaedic surgeons completed the survey. Definitions, further diagnostics, and treatments varied considerably amongst respondents. Angle measurements of the fat pad as related to the humeral axis line showed the highest reliability (test–retest ICC, 0.95 (95% CI 0.88–0.98); inter-rater ICC, 0.95 (95% CI 0.91–0.98)). A cut-off angle of 16° was defined a positive anterior FPS (sensitivity, 1.00; specificity, 0.87; accuracy, 99%), based on the respondents’ assessment of the radiographs in combination with the research team’s measurements. Any visible posterior fat pad was defined as a positive posterior FPS. This study provides insight into the current diagnosis and treatment of children with a radiological fat pad sign of the elbow. A clear, objective definition of a positive anterior FPS was identified as a ≥16° angle with respect to the anterior humeral line.

Aims: Paediatric fractures are highly prevalent and are most often treated with plaster. The application and removal of plaster is often an anxiety-inducing experience for children. Decreasing the anxiety level may improve the patients’ satisfaction and the quality of healthcare. Virtual reality (VR) has proven to effectively distract children and reduce their anxiety in other clinical settings, and it seems to have a similar effect during plaster treatment. This study aims to further investigate the effect of VR on the anxiety level of children with fractures who undergo plaster removal or replacement in the plaster room.Methods: A randomized controlled trial was conducted. A total of 255 patients were included, aged five to 17 years, who needed plaster treatment for a fracture of the upper or lower limb. Randomization was stratified for age (five to 11 and 12 to 17 years). The intervention group was distracted with VR goggles and headphones during the plaster treatment, whereas the control group received standard care. As the primary outcome, the post-procedural level of anxiety was measured with the Child Fear Scale (CFS). Secondary outcomes included the children’s anxiety reduction (difference between CFS after and CFS before plaster procedure), numerical rating scale (NRS) pain, NRS satisfaction of the children and accompanying parents/guardians, and the children’s heart rates during the procedure. An independent-samples t-test and Mann-Whitney U test (depending on the data distribution) were used to analyze the data.Results: The post-procedural CFS was significantly lower (p < 0.001) in the intervention group (proportion of children with no anxiety = 78.6%) than in the control group (56.8%). The anxiety reduction, NRS pain and satisfaction scores, and heart rates showed no significant differences between the control group and the intervention group. Subanalyses showed an increased effect of VR on anxiety levels in young patients, females, upper limb fractures, and those who had had previous plaster treatment.Conclusion: VR effectively reduces the anxiety levels of children in the plaster room, especially in young girls. No statistically significant effects were seen regarding pain, heart rate, or satisfaction scores.Cite this article: Bone Joint J 2024;106-B(7):728–734.

Frozen shoulder (FS) is a common cause of shoulder pain and stiffness. Conservative treatment is sufficient for the majority of patients with long-term recovery of shoulder function. Manipulation under anesthesia (MUA) is known as a well-established treatment option if conservative treatment fails. It is unknown whether MUA does indeed shorten the duration of symptoms or leads to a superior outcome compared to conservative treatment. The objective of the current trial is to evaluate the effectiveness of MUA followed by a physiotherapy (PT) program compared to a PT program alone in patients with stage 2 FS. A prospective, single-center randomized controlled trial was performed. Patients between 18 and 70 years old with stage 2 FS were deemed eligible if an initial course of conservative treatment consisting of PT and intra-articular corticosteroid infiltration was considered unsatisfactory. Patients were randomized, and data was collected with an online data management platform (CASTOR). MUA was performed by a single surgeon under interscalene block, and intensive PT treatment protocol was started within 4 hours after MUA. In the PT group, patients were referred to instructed physiotherapist, and treatment was guided by tissue irritability. The primary outcome was the Shoulder Pain and Disability Index (SPADI) score. Secondary outcomes were pain, range of motion (ROM), Oxford Shoulder Score, quality of life, and ability to work. In total, 82 patients were included, 42 in the PT group and 40 in the MUA group. There was a significant improvement in SPADI, Oxford Shoulder Score, pain, ROM, and quality of life in both groups at 1-year follow-up. SPADI scores at three months were significantly improved in favor of MUA. MUA showed a significantly bigger increase in anteflexion and abduction compared to PT at all points of follow-up. No significant differences between both groups were found for all other parameters. No fractures, dislocations, or brachial plexus injuries occurred in this trial. MUA in stage 2 FS can be considered safe and results in a faster recovery of ROM and improved functional outcome, measured with SPADI scores, compared to PT alone in the short term. After 1 year, except for slightly better ROM scores for MUA, the result of MUA is equal to PT.

Background: Paediatric fractures are highly prevalent and are most often treated with plaster. The removal of plaster is often an anxious experience for children. Virtual reality (VR) has proven to effectively distract children and reduce their anxiety in other clinical settings. This study aims to investigate the effect of VR on the anxiety level of children with fractures that undergo plaster removal or replacement in the plaster room. Methods: This study is designed as a randomised controlled trial (RCT). The sample size is 270 patients, aged 5 to 17 years, with a fracture of the upper or lower extremity treated with plaster. The intervention group will be distracted with VR goggles and headphones during the replacement or removal of the plaster, whereas the control group will receive standard care. As a primary outcome, the level of anxiety will be measured with the Child Fear Scale (CFS). Secondary outcomes include anxiety reduction (difference between CFS after and CFS before plaster procedure) and Numeric Rating Scales (NRS) pain and satisfaction. Additionally, the children’s fastest heart rate during the procedure will be recorded. An unpaired samples t-test or a Mann-Whitney U test (depending on the data distribution) will be used to analyse the data. Discussion: When completed, this trial will provide evidence on the potential role of VR in children with fractures treated with plaster. The purpose is to increase the quality of healthcare by decreasing anxiety and possibly pain perception of children during a plaster procedure. Trial registration: Netherlands Trial Register NL9065. Registered on 27 November 2020

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.