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The primary objective of this study was to develop a validated classification system for assessing iatrogenic bone trauma and soft-tissue injury during total hip arthroplasty (THA). The secondary objective was to compare macroscopic bone trauma and soft-tissues injury in conventional THA (CO THA) versus robotic arm-assisted THA (RO THA) using this classification system.

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The aims of this study were to describe the demographic, socioeconomic, and educational factors associated with core surgical trainees (CSTs) who apply to and receive offers for higher surgical training (ST3) posts in Trauma & Orthopaedics (T&O).

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Sagittal plane imbalance (SPI), or asymmetry between extension and flexion gaps, is an important issue in total knee arthroplasty (TKA). The purpose of this study was to compare SPI between kinematic alignment (KA), mechanical alignment (MA), and functional alignment (FA) strategies.

Hip precautions following total hip arthroplasty (THA) limits flexion, adduction and internal rotation, yet these precautions cause unnecessary psychological stress. This study aims to assess bony and implant impingement using virtual models from actual patient's bony morphology and spinopelvic parameters to deduce whether hip precautions are necessary with precise implant positioning in the Asian population. Individualized sitting and standing sacral slope data of robotic THAs performed at two tertiary referral centers in Hong Kong was inputted into the simulation system based on patients’ pre-operative sitting and standing lumbar spine X-rays. Three-dimensional dynamic models were reconstructed using the Stryker Mako THA 4.0 software to assess bony and implant impingement both anteriorly and posteriorly, with default cup placement at 40° inclination and 20° anteversion. Femoral anteversion followed individual patient's native version. A 36mm hip ball was chosen for all cups equal or above 48mm and 32mm for those below. Anterior impingement was assessed by hip flexion and posterior impingement was assessed by hip extension. 113 patients were included. At neutral rotation and adduction, no patients had anterior implant impingement at hip flexion of 100°. 1.7% had impingement at 110°, 3.5% had impingement at 120°, 9.7% had impingement at 130°. With 20° of internal rotation and adduction, 0.8% had anterior implant impingement at hip flexion of 90°, 7.1% had impingement at 100° and 18.5% had impingement at 110°. With the hip externally rotated by 20°, 0.8% of patients had posterior implant impingement, and 8.8% bony impingement at 0° extension. With enabling technology allowing accurate component positioning, hip precautions without limiting forward flexion in neutral position is safe given precise implant positioning and adequate osteophyte removal. Patients should only be cautioned about combined internal rotation, adduction with flexion

Aims. Precise implant positioning, tailored to individual spinopelvic biomechanics and phenotype, is paramount for stability in total hip arthroplasty (THA). Despite a few studies on instability prediction, there is a notable gap in research utilizing artificial intelligence (AI). The objective of our pilot study was to evaluate the feasibility of developing an AI algorithm tailored to individual spinopelvic mechanics and patient phenotype for predicting impingement. Methods. This international, multicentre prospective cohort study across two centres encompassed 157 adults undergoing primary robotic arm-assisted THA. Impingement during specific flexion and extension stances was identified using the virtual range of motion (ROM) tool of the robotic software. The primary AI model, the Light Gradient-Boosting Machine (LGBM), used tabular data to predict impingement presence, direction (flexion or extension), and type. A secondary model integrating tabular data with plain anteroposterior pelvis radiographs was evaluated to assess for any potential enhancement in prediction accuracy. Results. We identified nine predictors from an analysis of baseline spinopelvic characteristics and surgical planning parameters. Using fivefold cross-validation, the LGBM achieved 70.2% impingement prediction accuracy. With impingement data, the LGBM estimated direction with 85% accuracy, while the support vector machine (SVM) determined impingement type with 72.9% accuracy. After integrating imaging data with a multilayer perceptron (tabular) and a convolutional neural network (radiograph), the LGBM’s prediction was 68.1%. Both combined and LGBM-only had similar impingement direction prediction rates (around 84.5%). Conclusion. This study is a pioneering effort in leveraging AI for impingement prediction in THA, utilizing a comprehensive, real-world clinical dataset. Our machine-learning algorithm demonstrated promising accuracy in predicting impingement, its type, and direction. While the addition of imaging data to our deep-learning algorithm did not boost accuracy, the potential for refined annotations, such as landmark markings, offers avenues for future enhancement. Prior to clinical integration, external validation and larger-scale testing of this algorithm are essential. Cite this article: Bone Jt Open 2024;5(8):671–680

Background. Immersive virtual reality (VR) demonstrates potential benefits in patients with chronic low back pain (CLBP). However, few studies have investigated the feasibility and the acceptability of introducing immersive VR for use with patients with CLBP and in the Kingdom of Saudi Arabia (KSA). Aim. To investigate immersive VR's feasibility, tolerability, and acceptability as a rehabilitation intervention for adult patients with CLBP and explore the views of relevant Health Care Practitioners (HCPs) in the KSA. Methodology and Methods. A multi-centre, mixed-methods, explanatory sequential design was adopted to test immersive VR's feasibility, tolerability, and acceptability. An uncontrolled feasibility trial was conducted. The immersive VR intervention involved a training session followed by three sessions over one week using commercially available hardware and software. Feasibility outcomes were collected from patients immediately post-intervention. Patients and HCPs were recruited for semi-structured interviews. Results. Thirty-three patients and three HCPs were recruited. The feasibility a priori criteria were met for recruitment, retention, dropout, completeness of questionnaire data, treatment compliance and fidelity. Adverse events included one who reported aggravation of tinnitus, whereas two experienced dizziness. Qualitative data suggested that entertainment and motivation were key enablers. Barriers included technological capability and HCPs’ perceptions that immersive VR was time-consuming. Conclusion. The results suggested that immersive VR was feasible, acceptable, and tolerable among patients with CLBP and HCPs in clinical settings in the KSA. Further research focusing on the effectiveness is warranted in this field. Conflicts of Interest. None. Sources of Funding. None. Trial registration number. ISRCTN14434517

Background. Embodiment- and distraction-based approaches to immersive virtual reality (IVR) show promise in treating persistent low back pain (PLBP). However, which approach is more effective is unclear. This study aims to evaluate the impact of distraction- and embodiment-based IVR on pain processing and patient-reported outcome measures in PLBP. Method. Individuals with PLBP were randomised to receive eight sessions of either distraction- or embodiment-based IVR over two weeks. Outcome measures were evaluated at baseline and after the eighth session. Pain processing was evaluated using conditioned pain modulation (CPM) and temporal summation (TS). Results. Three participants (n=2 embodiment, n=1 distraction) have completed all eight IVR sessions. Preliminary results indicate a decrease from pre to post-intervention in Numerical Pain Rating Scale score (pre: 5/10, 6/10, 5/10; post: 2/10, 5/10, 2/10) and Pain Catastrophising Scale score (pre: 34/52, 11/52, 38/52; post: 11/52, 8/52, 12/52), with no clear trend in other self-reported measures (Hospital Anxiety and Depression scale, Oswestry low back disability questionnaire, fear-avoidance beliefs questionnaire, Tampa scale of kinesiophobia). Preliminary results suggest a potential increase in NPRS absolute values from pre- to post-intervention in CPM (pre: -2.7, -2.3, -2.0; post: -3.3, -2.0, -4.3) and TS (pre-1.2, 2.5, 2.4; post: 1.4, 2.5, 3.1). Conclusion. Eight sessions of IVR may reduce pain severity and pain catastrophising in people with PLBP and may increase the efficacy of endogenous pain modulatory systems. Data collection is ongoing to compare the effect of distraction- and embodiment-based IVR. Conflicts of Interest. There are no conflicts of interest. Sources of Funding. This project is funded by the Saudi Arabia Cultural Bureau

Aims. The aims of this study were: 1) to describe extended restricted kinematic alignment (E-rKA), a novel alignment strategy during robotic-assisted total knee arthroplasty (RA-TKA); 2) to compare residual medial compartment tightness following virtual surgical planning during RA-TKA using mechanical alignment (MA) and E-rKA, in the same set of osteoarthritic varus knees; 3) to assess the requirement of soft-tissue releases during RA-TKA using E-rKA; and 4) to compare the accuracy of surgical plan execution between knees managed with adjustments in component positioning alone, and those which require additional soft-tissue releases. Methods. Patients who underwent RA-TKA between January and December 2022 for primary varus osteoarthritis were included. Safe boundaries for E-rKA were defined. Residual medial compartment tightness was compared following virtual surgical planning using E-rKA and MA, in the same set of knees. Soft-tissue releases were documented. Errors in postoperative alignment in relation to planned alignment were compared between patients who did (group A) and did not (group B) require soft-tissue releases. Results. The use of E-rKA helped restore all knees within the predefined boundaries, with appropriate soft-tissue balancing. E-rKA compared with MA resulted in reduced residual medial tightness following surgical planning, in full extension (2.71 mm (SD 1.66) vs 5.16 mm (SD 3.10), respectively; p < 0.001), and 90° of flexion (2.52 mm (SD 1.63) vs 6.27 mm (SD 3.11), respectively; p < 0.001). Among the study population, 156 patients (78%) were managed with minor adjustments in component positioning alone, while 44 (22%) required additional soft-tissue releases. The mean errors in postoperative alignment were 0.53 mm and 0.26 mm among patients in group A and group B, respectively (p = 0.328). Conclusion. E-rKA is an effective and reproducible alignment strategy during RA-TKA, permitting a large proportion of patients to be managed without soft-tissue releases. The execution of minor alterations in component positioning within predefined multiplanar boundaries is a better starting point for gap management than soft-tissue releases. Cite this article: Bone Jt Open 2024;5(8):628–636

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This study aimed to evaluate if total knee arthroplasty (TKA) femoral components aligned in either mechanical alignment (MA) or kinematic alignment (KA) are more biomimetic concerning trochlear sulcus orientation and restoration of trochlear height.

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Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up.

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

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Ankle fractures are common, mainly affecting adults aged 50 years and over. To aid recovery, some patients are referred to physiotherapy, but referral patterns vary, likely due to uncertainty about the effectiveness of this supervised rehabilitation approach. To inform clinical practice, this study will evaluate the effectiveness of supervised versus self-directed rehabilitation in improving ankle function for older adults with ankle fractures.

Background. The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to classify the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods. We included 20 cavovarus feet from adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, 14 males). Patients included had flexible deformities, with no previous surgery. Previous work established majority of rotational deformity in cavovarus feet occurs at the talonavicular joint, which is often reduced during surgery. Using specialised software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using data from normal feet as a guide, the talonavicular joint of the cavovarus feet was digitally reduced to a ‘normal’ position. Models of the corrected position were exported and geometrically analysed using Blender 3.6 to identify anatomical trends. Results. We identified 3 types of cavovarus forefoot morphotypes. Type 1 was seen in 13 cases (65%) and was defined as a foot where only the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular correction. Type 2 was seen in 4 cases (20%) and was defined as a foot where the second and first metatarsals were progressively plantarflexed, with no significant adduction. Type 3 was seen in 3 cases (15%) and was defined as a foot where the metatarsals were still adducted after talonavicular de-rotation. Conclusion. We classify 3 forefoot morphotypes in cavovarus feet. It is important to recognise and anticipate the residual forefoot deformities after hindfoot correction as different treatment strategies may be required for different morphotypes to achieve balanced correction

Introduction. Treatment pathways of 5. th. metatarsal fractures are commonly directed based on fracture classification, with Jones types for example, requiring closer observation and possibly more aggressive management. Primary objective. To investigate the reliability of assessment of subtypes of 5. th. metatarsal fractures by different observers. Methods. Patients were identified from our prospectively collected database. We included all patient referred to our virtual fracture clinic with a suspected or confirmed 5. th. metatarsal fracture. Plain AP radiographs were reviewed by two observers, who were initially trained on the 5. th. metatarsal classification identification. Zones were defined as Zone 1.1, 1.2, 1.3, 2, 3, diaphyseal shaft (DS), distal metaphysis (DM) and head. An inter-observer reliability analysis using Cohen's Kappa coefficient was carried out, and degree of observer agreement described using Landis & Koch's description. All data was analysed using IBM SPSS v.27. Results. 878 patients were identified. The two observers had moderate agreement when identifying fractures in all zones, apart from metatarsal head fractures, which scored substantial agreement (K=.614). Zones 1.1 (K=.582), 2 (K=.536), 3 (K=.601) and DS (K=.544) all tended towards but did not achieve substantial agreement. Whilst DS fractures achieved moderate agreement, there was an apparent difficulty with distal DS, resulting in a lot of cross over with DM (DS 210 vs 109; DM 76 vs 161). Slight agreement with the next highest adjacent zone was found when injuries were thought to be in zones 1.2, 1.3 and 2 (K=0.17, 0.115 and 0.152 respectively). Conclusions. Reliability of sub-categorising 5. th. metatarsal fractures using standardised instructions conveys moderate to substantial agreement in most cases. If the region of the fracture is going to be used in an algorithm to guide a management plan and clinical follow up during a virtual clinic review, defining fractures of zones 1–3 needs careful consideration

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During total knee replacement (TKR), surgeons can choose whether or not to resurface the patella, with advantages and disadvantages of each approach. Recently, the National Institute for Health and Care Excellence (NICE) recommended always resurfacing the patella, rather than never doing so. NICE found insufficient evidence on selective resurfacing (surgeon’s decision based on intraoperative findings and symptoms) to make recommendations. If effective, selective resurfacing could result in optimal individualized patient care. This protocol describes a randomized controlled trial to evaluate the clinical and cost-effectiveness of primary TKR with always patellar resurfacing compared to selective patellar resurfacing.

INTRODUCTION. Simulation plays an important role in surgical education and the ability to perfect surgical performance. Simulation can be enhanced by adding various layers of realism to the experience. Haptic feedback enhances the simulation experience by providing tactile responses and virtual reality imagery provides an immersive experience and allows for greater appreciation of three-dimensional structures. In this study, we present a proof-of-concept haptic simulator to replicate key steps of a cervical laminoplasty procedure. The technology uses affordable components and is easily modifiable so that it can be used from novice through to expert level. Custom models can be easily added ensuring the simulator can be used in a wide range of orthopaedic applications from baseline education through to day of surgery pre-operative simulation. METHOD. We used the Unity Game Engine, the 3D Systems “Touch” Haptic Feedback Device (HFD), and a Meta Quest VR headset. Our system uses a number of complex algorithms to track the shape and provide haptic feedback of a virtual bone model. This allows for simulation of various tools including a high-speed burr, Kerrison rongeur and intraoperative X-rays. RESULTS. Our simulator replicates the tactile sensations of bone-burring tasks. Although we focused on the cervical laminoplasty procedure, the system can load data from CT scans, enabling the simulation of multiple other procedures. The parts cost of our system, $10,000 NZD, is a fraction of the cost of traditional surgical simulators. DISCUSSION. Our simulator reduces financial barriers to accessing orthopaedic simulators. Trainees can perform hands-on practice without compromising patient safety. The immersive nature of VR, combined with realistic haptic feedback, enables trainees to develop the dexterity and three-dimensional understanding of detailed bony work. Further refinements are needed before we can perform validation studies on our system. CONCLUSIONS. We present an affordable surgical simulator capable of simulating bony surgical procedures in a VR environment using haptic feedback technology and consumer-grade components. ACKNOWLEDGEMENTS. This research was made possible by the generosity of the Wishbone Trust

Ideally the hip arthroplasty should not be subject to bony or prosthetic impingement, in order to minimise complications and optimise outcomes. Modern 3d planning permits pre-operative simulation of the movements of the planned hip arthroplasty to check for such impingement. For this to be meaningful, however, it is necessary to know the range of movement (ROM) that should be simulated. Arbitrary “normal” values for hip ROM are of limited value in such simulations: it is well known that hip ROM is individualised for each patient. We have therefore developed a method to determine this individualised ROM using CT scans. CT scans were performed on 14 cadaveric hips, and the images were segmented to create 3d virtual models. Using Matlab software, each virtual hip was moved in all potential directions to the point of bony impingement, thus defining an individualised impingement-free 3d ROM envelope. This was then compared with the actual ROM as directly measured from each cadaver using a high-resolution motion capture system. For each hip, the ROM envelope free of bony impingement could be described from the CT and represented as a 3d shape. As expected, the directly measured ROM from the cadaver study for each hip was smaller than the CT-based prediction, owing to the presence of constraining soft tissues. However, for movements associated with hip dislocation (such as flexion with internal rotation), the cadaver measurements matched the CT prediction, to within 10°. It is possible to determine an individual's range of clinically important hip movements from a CT scan. This method could therefore be used to create truly personalised movement simulation as part of pre-operative 3d surgical planning

The purpose of this modified Delphi study was to obtain consensus on wound closure (including best practices for each tissue layer of closure) and dressing management in total hip arthroplasty (THA), using an evidence-based approach. The Delphi panel included 20 orthopedic surgeons from Europe and North America. Eighteen statements were identified (14 specific to THA and 4 relating to both THA and total knee arthroplasty) using a targeted literature review. Consensus was developed on the statements with up to three rounds of anonymous voting per topic. Panelists ranked their agreement with each statement on a five-point Likert scale. An a priori threshold of 75% was required for consensus. In Round 1, 15 of 18 statements achieved consensus via a structured electronic questionnaire. In Round 2, the 3 statements that did not achieve consensus were revised during a virtual face to face meeting. An additional 2 statements were edited for clarity. In Round 3, the 5 revised statements achieved consensus via a structured electronic questionnaire. Wound closure related interventions that were recommended for use in THA included: 1) barbed sutures over non-barbed sutures (shorter closing times and overall cost savings); 2) subcuticular sutures over skin staples (lower risk of infections and higher patient preference); 3) mesh-adhesives over silver-impregnated dressings (lower rate of wound complications); 4) negative pressure wound therapy over other dressings (lower wound complications and reoperations and fewer dressing changes); 5) triclosan coated sutures (lower risk of surgical site infection). Using a modified Delphi approach, a panel of 20 orthopedic surgeons achieved consensus on 18 statements pertaining to multi-layer wound closure and dressing management in THA. This study forms the basis for identifying critical evidence gaps within wound management to help reduce variability in outcomes during THA

Aims. The aim of this study was to compare the biomechanical models of two frequently used techniques for reconstructing severe acetabular defects with pelvic discontinuity in revision total hip arthroplasty (THA) – the Trabecular Metal Acetabular Revision System (TMARS) and custom triflange acetabular components (CTACs) – using virtual modelling. Methods. Pre- and postoperative CT scans from ten patients who underwent revision with the TMARS for a Paprosky IIIB acetabular defect with pelvic discontinuity were retrospectively collated. Computer models of a CTAC implant were designed from the preoperative CT scans of these patients. Computer models of the TMARS reconstruction were segmented from postoperative CT scans using a semi-automated method. The amount of bone removed, the implant-bone apposition that was achieved, and the restoration of the centre of rotation of the hip were compared between all the actual TMARS and the virtual CTAC implants. Results. The median amount of bone removed for TMARS reconstructions was significantly greater than for CTAC implants (9.07 cm. 3. (interquartile range (IQR) 5.86 to 21.42) vs 1.16 cm. 3. (IQR 0.42 to 3.53) (p = 0.004). There was no significant difference between the median overall implant-bone apposition between TMARS reconstructions and CTAC implants (54.8 cm. 2. (IQR 28.2 to 82.3) vs 56.6 cm. 2. (IQR 40.6 to 69.7) (p = 0.683). However, there was significantly more implant-bone apposition within the residual acetabulum (45.2 cm. 2. (IQR 28.2 to 72.4) vs 25.5 cm. 2. (IQR 12.8 to 44.1) (p = 0.001) and conversely significantly less apposition with the outer cortex of the pelvis for TMARS implants compared with CTAC reconstructions (0 cm. 2. (IQR 0 to 13.1) vs 23.2 cm. 2. (IQR 16.4 to 30.6) (p = 0.009). The mean centre of rotation of the hip of TMARS reconstructions differed by a mean of 11.1 mm (3 to 28) compared with CTAC implants. Conclusion. In using TMARS, more bone is removed, thus achieving more implant-bone apposition within the residual acetabular bone. In CTAC implants, the amount of bone removed is minimal, while the implant-bone apposition is more evenly distributed between the residual acetabulum and the outer cortex of the pelvis. The differences suggest that these implants used to treat pelvic discontinuity might achieve short- and long-term stability through different biomechanical mechanisms. Cite this article: Bone Joint J 2024;106-B(5 Supple B):74–81

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The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?