Aims

Unicompartmental knee arthroplasty (UKA) is associated with an accelerated recovery, improved functional outcomes, and retention of anatomical knee kinematics when compared to manual total knee arthroplasty (mTKA). UKA is not universally employed by all surgeons as there is a higher revision risk when compared to mTKA. Robotic arm-assisted (ra) UKA enables the surgeon to position the prosthesis more accurately when compared to manual UKA, and is associated with improved functional outcomes and a lower early revision risk. Non-randomized data suggests that, when compared to mTKA, raUKA has a clinically meaningful greater functional benefit. This protocol describes a randomized controlled trial that aims to evaluate the clinical and cost-effectiveness of raUKA compared to mTKA for individuals with isolated medial compartment osteoarthritis (OA).

Aims. This study aimed to investigate whether the use of CT-based navigation enhances: 1) the accuracy of cup placement; and 2) the achievement rate of required range of motion (ROM). Additionally, we investigated the impact of using a large femoral head and dual-mobility liner on the achievement rates. Methods. This retrospective study analyzed 60 manual and 51 CT-based navigated primary total hip arthroplasties performed at a single facility. Postoperative CT scans and CT-based simulation software were employed to measure the cup orientation and to simulate the ROM. We compared the absolute errors for radiological inclination (RI) and radiological anteversion (RA) between the two groups. We also examined whether the simulated ROM met the required ROM criteria, defined as flexion > 110°, internal rotation > 30°, extension > 30°, and external rotation > 30°. Furthermore, we performed simulations with 36 mm femoral head and dual-mobility liner. Results. The absolute errors of RI and RA from the preoperative plan were significantly smaller in the CT-based navigation group (3.7° (SD 3.5°) vs 5.1° (SD 3.5°); p = 0.022, and 3.9° (SD 3.5°) vs 6.8° (SD 5.0°); p = 0.001, respectively). The proportion of cases achieving the required ROM in all directions was significantly higher in the CT-based navigation group (42% vs 63%; p = 0.036). The achievement rates of the required ROM were significantly higher with the use of a 36 mm ball or dual-mobility liner compared to the use of a 32 mm ball (65% vs 51%; p = 0.040 and 77% vs 51%; p ≤ 0.001, respectively). Conclusion. CT-based navigation enhanced required ROM achievement rates by > 20%, regardless of the ball diameter. The improved accuracy of cup placement through CT-based navigation likely contributed to the enhancement. Furthermore, the use of large femoral heads and dual-mobility liners also improved the required ROM achievement rates. In cases with a high risk of dislocation, use of these devices is preferred. Cite this article: Bone Jt Open 2025;6(2):155–163

Aims

Machine learning (ML) holds significant promise in optimizing various aspects of total shoulder arthroplasty (TSA), potentially improving patient outcomes and enhancing surgical decision-making. The aim of this systematic review was to identify ML algorithms and evaluate their effectiveness, including those for predicting clinical outcomes and those used in image analysis.

Aims. To establish cut-off values for lateral pubofemoral distance (PFD) measurements for detecting hip dysplasia in early (four days) and standard care (six weeks) screening for developmental dysplasia of the hip (DDH). Methods. All newborns, during a one-year period (October 2021 to October 2022), were offered a PFD ultrasound (US) examination in addition to the existing screening programme for DDH. Newborns who were referred for standard care hip US, suspected for DDH, received a secondary PFD US examination in conjunction with the standard care Graf/Harcke hip US examination. Receiver operating characteristic curves and empirically optimal cut-off values were calculated with a true positive defined as a Graf type ≥ IIc hip. Results. We included 2,735 newborns, of whom 758 received both early PFD hip US and standard care Graf/Harcke hip US. For early (four days) PFD screening, the optimal cut-off point was calculated to be 6.2 mm (95% CI 4.7 to 7.7) producing a sensitivity of 80% (95% CI 55% to 100%) and a specificity of 87% (86% to 89%). For PFD screening performed at standard care (six weeks) hip US, the optimal cut-off point was calculated to be 5.6 mm (95% CI 4.9 to 6.3) producing a sensitivity of 100% (95% CI 100% to 100%) and a specificity of 96% (95% CI 95% to 97%). Conclusion. PFD US screening produces a high degree of both sensitivity and specificity for detecting DDH. Age-specific cut-off values should be used to heighten the accuracy of PFD US screening. Cite this article: Bone Jt Open 2025;6(2):119–125

Aims. The aim of the study was to apply 3D measurements for fracture displacement in minimally to moderately displaced acetabular fractures treated nonoperatively, and to evaluate whether this measurement can be used to estimate the likelihood of conversion to total hip arthroplasty (THA) at follow-up. Methods. A multicentre, cross-sectional study was performed on 144 patients who were treated nonoperatively for an acetabular fracture in four level 1 trauma centres between January 2000 and December 2020. For each patient, fracture displacement was measured on CT-based 3D models. The 3D gap area represents fracture displacement (mm. 2. ) between all fracture fragments. A receiver operating characteristic curve was generated to determine a 3D gap area threshold representing the optimal sensitivity and specificity to predict conversion to THA. Native hip survival was reported using Kaplan-Meier curves. Predictors of conversion to THA were determined using Cox regression analysis. Results. Of 144 patients, 18 (12%) received a THA. The median 3D gap area of the complete study cohort was 692 mm. 2. (IQR 216 to 1,400). Native hip survival in patients with a gap area threshold ≤ 1,171 or > 1,171 mm. 2. differed at one-year (98% vs 85%), two-year (96% vs 77%), and five-year follow-up (92% vs 73%). 3D gap area > 1,171 mm. 2. (hazard ratio (HR) 4.3; 95% CI 1.7 to 11.0) and the presence of osteoarthritis grade 2 or higher (HR 3.1; 95% CI 1.2 to 7.8) independently predicted the likelihood of conversion to THA during follow-up. Conclusion. For nonoperatively treated acetabular fractures, introducing 3D gap area assessment to measure fracture displacement offers a promising approach for assessing the risk of conversion to THA. With the introduction of (semi-)automatic segmentation and measurement techniques, or their implementation into commercially available software, this 3D gap area measurement can serve as an addition to the Letournel classification and an alternative to traditional 2D gap and step-off measurements, improving accuracy, reproducibility, and applicability in clinical decision-making. Cite this article: Bone Joint J 2025;107-B(2):204–212

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In this study, we aimed to evaluate incidence trends and potential risk factors associated with Perthes’ disease in Denmark, using publicly available data.

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Sagittal lumbar pelvic alignment alters with posterior pelvic tilt (PT) following total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). The individual value of pelvic sagittal inclination (PSI) following rebalancing of lumbar-pelvic alignment is unknown. In different populations, PT regresses in a linear relationship with pelvic incidence (PI). PSI and PT have a direct relationship to each other via a fixed individual angle ∠γ. This study aimed to investigate whether the new PI created by acetabular component positioning during THA also has a linear regression relationship with PT/PSI when lumbar-pelvic alignment rebalances postoperatively in patients with Crowe type III/IV DDH.

The February 2025 Trauma Roundup³⁶⁰ looks at: Risk factors for nonunion in femoral neck fracture patients with internal fixation: a multicentre (TRON group) retrospective study; Tranexamic acid administered at time of hospital admission does not decrease transfusion rates or blood loss for extracapsular hip fractures; The effect of anterior support screw (AS2) in unstable femoral trochanteric fractures; The effect of coronal plane angulation on patient-reported outcome measures of operatively treated distal femur fractures; Do proximal humerus fractures treated nonoperatively benefit from supervised physiotherapy?; Cephalomedullary nails: are dual lag screws superior to single lag screws?; Does cement need to be pressurized for hemiarthroplasty?.

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Complex elbow fracture-dislocations often result in suboptimal outcomes and necessitate a thorough understanding of injury patterns to guide effective management and reduce adverse sequelae. The Wrightington Classification System (WCS) offers a comprehensive approach and considers both bony and soft-tissue disruption, providing clearer guidance for treatment. This is the first external study to assess the reliability of the WCS for elbow fracture-dislocations.

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Older adults with hip fractures are at high risk of experiencing complications after surgery, but estimates of the rate of specific complications vary by study design and follow-up period. The aim of this systematic review was to determine the prevalence of complications in older adults after hip fracture surgery.

The February 2025 Wrist & Hand Roundup³⁶⁰ looks at: Delayed fixation of distal radial fractures beyond three weeks increases the odds of reoperation; A systematic review of management options for symptomatic scaphometacarpal impingement after trapeziectomy; Diagnosing occult scaphoid fractures: an art or science?; Dual-mobility trapeziometacarpal arthroplasty shows promising outcomes but lacks long-term evidence; 3D-printed titanium scaphoid implant offers a promising alternative for unreconstructable scaphoid nonunion; Lidocaine co-injection reduces pain intensity during corticosteroid injections in hand and wrist conditions; Long-term outcomes of PyroDisk arthroplasty for trapeziometacarpal osteoarthritis; Evaluating the impact of COVID-19 on hand surgery practices: adaptations and missed opportunities.

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The aim of this study was to evaluate the suitability, against an accepted international standard, of a linked hip fracture registry and routinely collected administrative dataset in England to embed and deliver randomized controlled trials (RCTs).

The February 2025 Oncology Roundup³⁶⁰ looks at:The role of bone grafting versus bone cement in the treatment of giant cell tumour of bone: a systematic review and meta-analysis on the risk of recurrence in 1,454 patients; Tumour necrosis drives prognosis in osteosarcoma; Correlation between post-chemotherapy MRI and histopathology of malignant bone tumours treated with extra-articular resection; Real-world referral pattern of unplanned excision in patients with soft-tissue sarcoma; Assessment of artificial intelligence chatbot responses to common patient questions on bone sarcoma; Chondrosarcoma of the pelvis and limbs at ten years; Chest wall resection and reconstruction for primary chest wall sarcomas: analysis of survival, predictors of outcome, and long-term functional status; Ewing’s sarcoma in the paediatric population: predictors of survival within the USA; Pulmonary metastasectomy for sarcoma: insights from a referral centre cohort.

The February 2025 Spine Roundup³⁶⁰ looks at: The effect of thoraco-lumbo-sacral orthosis wear time and clinical risk factors on curve progression for individuals with adolescent idiopathic scoliosis; Does operative level impact dysphagia severity after anterior cervical discectomy and fusion? A multicentre prospective analysis; Who gets better after surgery for degenerative cervical myelopathy? A responder analysis from the multicentre Canadian spine outcomes and research network; Do obese patients have worse outcomes in adult spinal deformity surgeries?; An update to the management of spinal cord injury; Classifying thoracolumbar injuries; High- versus moderate-density constructs in adolescent idiopathic scoliosis are equivalent at two years; Romosozumab for protecting against proximal junctional kyphosis in deformity surgery.

Aims

Radiostereometric analysis (RSA) is considered the gold standard for in vivo migration analysis, but CT-based alternatives show comparable results in the shoulder and hip. We have previously validated a CT-based migration analysis method (CTMA) in a knee phantom compared to RSA. In this study, we validated the method in patients undergoing total knee arthroplasty (TKA). Our primary outcome measure was the difference in maximum total point motion (MTPM) between the differing methods.

Aims. The aim of this study was to develop and evaluate a deep learning-based model for classification of hip fractures to enhance diagnostic accuracy. Methods. A retrospective study used 5,168 hip anteroposterior radiographs, with 4,493 radiographs from two institutes (internal dataset) for training and 675 radiographs from another institute for validation. A convolutional neural network (CNN)-based classification model was trained on four types of hip fractures (Displaced, Valgus-impacted, Stable, and Unstable), using DAMO-YOLO for data processing and augmentation. The model’s accuracy, sensitivity, specificity, Intersection over Union (IoU), and Dice coefficient were evaluated. Orthopaedic surgeons’ diagnoses served as the reference standard, with comparisons made before and after artificial intelligence assistance. Results. The accuracy, sensitivity, specificity, IoU, and Dice coefficients of the model for the four fracture categories in the internal dataset were as follows: Displaced (1.0, 0.79, 1.0, 0.70, 0.82), Valgus-impacted (1.0, 0.80, 1.0, 0.70, 0.82), Stable (0.99, 0.95, 0.99, 0.83, 0.89), and Unstable (1.0, 0.98, 0.99, 0.86, 0.92), respectively. For the external validation dataset, the sensitivity and specificity were as follows: Displaced (0.83, 0.94), Valgus-impacted (0.89, 0.90), Stable (0.88, 0.95), and Unstable (0.85, 0.99), respectively. The overall means (Micro AVG and Macro AVG) for the external dataset were Micro AVG (0.83 (SD 0.05), 0.96 (SD 0.01)) and Macro AVG (0.69 (SD 0.02), 0.95 (SD 0.02)), respectively. Conclusion. Compared to human diagnosis alone, our study demonstrates that the developed model significantly improves the accuracy of detecting and classifying hip fractures. Our model has shown great potential in assisting clinicians with the accurate diagnosis and classification of hip fractures. Cite this article: Bone Joint J 2025;107-B(2):213–220

Aims

While cementless fixation offers potential advantages over cemented fixation, such as a shorter operating time, concerns linger over its higher cost and increased risk of periprosthetic fractures. If the risk of fracture can be forecasted, it would aid the shared decision-making process related to cementless stems. Our study aimed to develop and validate predictive models of periprosthetic femoral fracture (PPFF) necessitating revision and reoperation after elective total hip arthroplasty (THA).