Aims. The Bracing Adolescent Idiopathic Scoliosis (BASIS) study is a randomized controlled non-inferiority pragmatic trial of ‘full-time bracing’ (FTB) compared to ‘night-time bracing’ (NTB) for the treatment of adolescent idiopathic scoliosis (AIS). We anticipated that recruiting patients to BASIS would be challenging, as it is a paediatric trial comparing two markedly different bracing pathways. No previous studies have compared the experiences of AIS patients treated with FTB to those treated with NTB. This qualitative study was embedded in BASIS to explore families’ perspectives of BASIS, to inform trial communication, and to identify strategies to support patients treated in a brace. Methods. Semi-structured interviews were conducted with parents (n = 26) and young people (n = 21) who had been invited to participate in BASIS at ten of the 22 UK paediatric spine services in hospitals recruiting to BASIS. Audio-recorded interviews were transcribed and analyzed thematically. Results. Families viewed their interactions with BASIS recruiters positively, but were often confused about core aspects of BASIS, such as the aims, expectations of bracing, and the process of randomization. Participants typically expressed a preference for NTB, but recruiters may have framed NTB more favourably. Patients and parents reported challenges wearing a brace, such as physical discomfort, feelings of self-consciousness, difficulty participating in physical activities, and strain on financial resources to support brace use. Patients in FTB reported more pronounced challenges. While families valued health professional support, they felt there was a lack of social, emotional, and school support, and relied on online resources, as well private counselling services to address this need. Conclusion. The findings informed the development of resources and strategies, including guidance for schools and the recommendations in this paper, to support patients to wear NTB and FTB as prescribed. The results indicated opportunities for recruiters to enhance trial communication in ways that could improve informed consent and recruitment to BASIS, and inform future trials of bracing. Cite this article: Bone Jt Open 2025;6(2):135–146

Aims. The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD. Methods. The study was conducted on 40 adult embalmed cadaveric lower limbs. Chopart joint complexes were dissected, and the structures supporting the joint inferiorly were observed and noted. Results. The articulating bones exhibit features like a cuboid shelf and navicular beak, which appear to offer inferior support to the joint. The expanse of the spring ligament complex is more medial than inferior, while the superomedial part is more extensive than the intermediate and inferoplantar parts. The spring ligament is reinforced by the tendons in the superomedial part (the main tendon of tibialis posterior), the inferomedial part (the plantar slip of tibialis posterior), and the master knot of Henry positioned just inferior to the gap between the inferomedial and inferoplantar bundles. Conclusion. This study highlights that the medial aspect of the talonavicular articulation has more extensive reinforcement in the form of superomedial part of spring ligament and tibialis posterior tendon. The findings are expected to prompt further research in weightbearing settings on the pathogenesis of flatfoot. Cite this article: Bone Jt Open 2024;5(4):335–342

Introduction. Adjusting an external fixator can be a daunting process for patients. Despite comprehensive training, patients often request supervision for the initial adjustments which may result in a prolonged hospital stay. Following the introduction of telemedicine during the pandemic we believed that this could be utilised to support patients with their fixator adjustments. A quality improvement project was implemented to assess and evaluate a change in practice from existing Face to Face support to a telemedicine format. The aim of the project was to reduce median length of stay (LOS). Materials & Methods. The telemedicine platform was introduced in our unit from April 2021 with the change in practice. Using the life QI platform, run charts were used to record the numbers of patients whose LOS was 4 days or less. Median LOS was assessed prior to and following introduction of the telemedicine platform. Service user experience with telemedicine as well as overall training and education by the CNS team was sought through on-line questionnaires. Results. Baseline data collected from April 2019 to April 2021 showed that our median LOS for patients undergoing external fixation was 6 days with 36% of patients being discharged at day 4 or earlier. After implementation of telemedicine, median LOS reduced to 4 days with 50% of patients leaving hospital in 4 days or less. Service user responses demonstrated that 100% felt that sufficient information was provided by the CNS team, a mean score of 8.4/10 was reported when asked how confident they were when adjusting the fixator. When asked how the service could be improved access to a recorded video was suggested. Conclusions. Initial fixator adjustment support via telemedicine is not appropriate for all of our patient group due to a lack of access or co-morbidities/ social issues that necessitate a prolonged hospital stay. However, this project has demonstrated that it has had positive long-term benefits within our service through reducing our median length of stay by 2 days without compromising patient satisfaction with their care

Background. Chronic pain is a significant burden and represents a major issue for world healthcare systems. Interventions include medication, surgery, pain management programmes, and social support through peer support groups. These groups are often informal, providing informational, emotional, and social support to members. The aim of this project is to co-produce guidance on how to establish a peer support programme for people living with chronic, non-cancer pain that is informed by evidence, theory, and stakeholder experience. Methods. This project is using Steps 1–4 of the Intervention Mapping (IM) approach to inform the research. Online workshops consisting of people living with chronic pain, third sector representatives, healthcare professionals, and researchers are being used to co-produce the guidance. Results. To date, 2 of the 4 planned workshops have been conducted. These have identified the needs of people living with chronic pain, goals for the peer support programme, and expectations of how a peer support programme should be executed. Topics for inclusion in the programme and their content have been identified, with further workshops to refine this planned. The final stage of this project will identify methods of delivery, specific resources that should be developed, and the training to be provided to peer support volunteers. Conclusion. The project has identified the diverse needs of people living with chronic pain and how these may be addressed by a peer support programme. It has identified flexible options that can be recommended to those who want to set up a programme and a variety content that may be included. Conflicts of Interest. None. Sources of Funding. Robert Gordon University

Background. Low back pain (LBP) is a major problem across the globe and is the leading cause worldwide of years lost to disability. Self-management is considered an important component the treatment of people with non-specific LBP. However, it seems that the self-management support for people with non-specific LBP provided by physiotherapists can be improved. Moreover, the way exercise therapists (ET) address self-management in practice is unknown. Purpose. To investigate the ideas, opinions and methods used by physiotherapists and ET with regard to self-management and providing self-management support to patients with non-specific LBP. Methods. This study was a qualitative survey. An online questionnaire with open-ended questions was developed. The survey was conducted among physiotherapists and ET working in the Netherlands. Data was analysed using thematic analysis. Results. Respondents considered self-management support an important topic in physiotherapy and exercise therapy for people with non-specific LBP. In the self-management support provided by the respondents, providing information and advice were frequently mentioned. The topics included in the support given by the respondents covered a broad range of important factors. The topics frequently focused on biomechanical factors. Therapists mainly provided patient education rather than self-management support. Moreover, important self-management skills were generally not addressed sufficiently. The majority of respondents had a need with regard to self-management or providing self-management support. These needs include having more knowledge, skills and tools aimed at facilitating self-management. Conclusion. The way physiotherapists and ET address self-management in people with non-specific LBP is not optimal and should be improved. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained. Previous publication: This work was published in a scientific journal: Hutting N, Oswald W, Staal JB, Heerkens YF. Self-management support for people with non-specific low back pain: A qualitative survey among physiotherapists and exercise therapists. Musculoskelet Sci Pract. 2020 Dec; 50:102269. doi: 10.1016/j.msksp.2020.102269. This work was never presented at a conference

Abstract. Introduction. The NHS long term plan endorses ‘personalised’, ‘digitally enabled’, ‘out of hospital’ care. Multiagency guidance (CPOC(2021)/NICE(2021)/GIRFT(2021)/NHSX(2021)) advocates an integrated ‘pathway’ approach to information sharing, shared-decision making and patient support. Digital solutions are the vehicle to deliver these agendas. Methods. In 2018 we developed a digital joint pathway (DJP) spanning the surgical care pathway (prehabilitation to rehabilitation) using the GoWellHealth platform. Patients listed for joint replacement are offered the DJP as routine care. Activity and engagement are monitored using the DJP data library. We sought to evidence our DJP by assessing patient engagement, experience and outcomes (OKS/EQ5D/Readmission). Results. Engagement. Consecutive cohort of the first 1195 patients registered. Activation rates were >85% and >70% viewed content within the DJP (median=15 access/pt; mean=83 minutes on DJP/pt). Engagement was similar irrespective of age and gender (p=NS). Older patients preferred to access via a computer. Experience. Qualitative interviews (n=14) demonstrated patients felt the DJP impacted positively on their health behaviours and contributed to their recovery. They spoke positively about the use of technology and the accessibility of the DJP. Outcomes. Comparison of patients on the DJP versus those not on the DJP using adjusted regression models demonstrated improved EQ5D=0.070 (95%CI=0.004-0.135,p=0.04), OKS=5.0 (95%CI=2.2-7.8,p<0.001) and readmission rates (3.6% versus 5.6%,p<0.01) for DJP patients. Conclusions. A DJP model for information delivery and patient support, across the entirety of the surgical pathway, is feasible and demonstrates high levels of patient engagement, experience and improved patient outcomes

Aim. The analysis of synovial fluid has proved to be of crucial importance in the diagnostic process of prosthetic joint infections (PJI), suggesting the presence of an infection before the microbiological culture results. In this context, several studies illustrated the efficacy of synovial calprotectin in supporting the diagnosis of PJI [1, 2]. However, several testing methods have been explored to detect synovial calprotectin levels, emphasizing the need to use a standardized, rapid and rapid test. In this study, synovial calprotectin was analyzed by means of a commercial stool test [3] to explore whether the detected levels might predict PJIs and, therefore, being a promising tool for the fast and reliable diagnosis of this complication. Method. The synovial fluid of 55 patients underwent to revision of the prosthetic implant were analyzed. The measurement of calprotectin was carried out by of commercial stool test, following the protocol for liquid samples. Calprotectin levels were then compared to other synovial biomarkers of PJI such as leucocyte esterase and count and percentage of polymorphonuclear cells. Data analysis were performed using R software v4.1.1 (R Core Team) and package “pROC” [4]. Receiver operator characteristics curves were designed using culture test as gold standard to evaluate the area under curve (AUC) of each method (with DeLong method for confidence-interval calculation). Thresholds were calculated to maximize Youden's index; sensitivity and specificity were reported. One-to-one Pearson's correlations coefficient were calculated for each pair of methods. P value <0.05 were considered statistically significant. Results. Of the 55 synovial fluids analyzed, 13 patients were diagnosed with PJI and 42 with an aseptic failure of the implant. The specificity, sensitivity, and AUC of calprotectin resulted 0.90, 0.85, and 0.86 (95%CI: 0.72–0.99), respectively with a set threshold of 226.5 µg/g. The values of calprotectin had a moderate and statistically relevant correlation with the synovial leucocyte counts (r. s. = 0.54, p = 0.0003) and the percentage of polymorphonuclear cells (r. s. = 0.68, p = 0.0000). Conclusions. From this analysis, it can be concluded that synovial calprotectin is a valuable biomarker that correlates with other established indicator of local infection, delivering a rapid and reliable results and supporting the diagnostic process of PJI

The requirement for the peer support groups were born out of concern for the psychological wellbeing of the paediatric patients and to assess if this would improve their wellbeing during their treatment. Groupwork is a method of Social Work which is recognised as a powerful tool to allow people meet their need for belonging while also creating the forum for group members to empower one another. Social Work meet with all paediatric patients attending the limb reconstruction service in the hospital. The focus of the Medical Social Worker (MSW) is to provide practical and emotional support to the patient and their parent/guardian regarding coping with the frame. Some of the challenges identified through this direct work include patient's struggling with the appearance of the frame and allowing peers to see the frame. The peer support group aims to offer its attendees the opportunities to engage with fellow paediatric patients in the same position. It allowed them to visually identify with one another. We wanted to create a safe space to discuss the emotional impact of treatment and the frames. It normalises the common problems paediatric patients face during treatment. We assisted our participants to identify new coping techniques and actions they can take to make their journey through limb reconstruction treatment more manageable. Finally, we aimed to offer the parents space to similarly seek peer support with regard to caring for a child in treatment. All paediatric patients were under the care of the Paediatric Orthopaedic Consultant and were actively engaging with the limb reconstruction multi-disciplinary team (MDT). The patient selection was completed by the MDT; based on age, required to be in active treatment, or their frames were removed within one month prior to the group's commencement. Qualitative data was collected through written questionnaires and reflection from participants in MSW sessions. We also used observational data from direct verbal feedback from the MDT. In the first group, parents gave feedback due to participants age and completed written feedback forms. For our second group, initial feedback was collated from the participants after the first session to get an understanding of group expectations. Upon completion, we collected data from both the participants and the parents. Qualitative and scaling questions gathered feedback on their experience of participating in the group. We held two peer support groups in 2022:One group for patients aged between 3–6 years in January 2022 across two sessions, which was attended by four patients. The second group for young teenage patients aged between 11–15 years in April 2022 across four sessions, which was attended by five patients. The written feedback received from group one focused on eliciting the participant's experience of the groupwork. 100% of participants identified the shared experience as the main benefit of the groupwork. 100% of participants agreed they would attend a peer support group again, and no participant had suggestions for improvement to the group. Feedback did indicate that group work at the beginning of treatment could be more beneficial. In relation to the second group, 60% of the paediatric patients and their parents returned the questionnaires. All of the parent's feedback identified that it was beneficial for their child to meet peers in a similar situation. They agreed that it was beneficial to meet other parents, so they could get support and advice from one another. On a scale between 1 and 5, 5 being the highest score, the participants scored high on the group work meeting their expectations, enjoyment of the sessions, and the group work was a beneficial aspect of their treatment. All respondents would strongly recommend groupwork to other paediatric patients attending for limb reconstruction treatment. Overall, the MDT limb reconstruction team, found the peer support group work of great benefit to the participants and their parents. The MSW team identified that during a period on the limb reconstruction team, when a high number of patients were in active treatment, the workload of the MSW also increased reflecting this activity. Common issues and concerns were raised directly to MSW (particularly from group two) regarding numerous difficulties they experienced trying to cope with the frame. The group work facilitators created a space where the participants could get peer support, share issues caused by the frame, hear directly from others, and that they too experience similar feelings or issues. Collectively, they identified ways of coping and promoting their own wellbeing while in treatment. The participants in group two, subsequently created a group on social media, to be able to continue their newly formed friendships and to continue to update one another on their treatment journeys. The participants self-requested another group in the future. This was facilitated in November 2023, the facilitators sought more feedback from all participants and their parents after this session. These findings will contribute towards the analysis for the presentation. Peer support groupwork was presented at the hospital's foundation day and has been well received by senior management in the hospital, as a positive addition to the limb reconstruction service. The focus of the MDT in 2024, is to further develop and facilitate more peer support groups for our paediatric patients

Background. A local authority approached us, for a cost-beneficial solution to their increasing low back pain referrals. We proposed developing a student-led clinic – an intervention delivered by students but supervised by clinicians. We then conducted scoping reviews on student-led clinics in the management of health conditions and on the self-management of back pain. The findings suggested that student-led self-management interventions for low back health should be feasible. The next step was to co-construct the intervention with key stakeholders. Co-Construction. A hybrid of Action Research and Design Science methodology was used to co-construct the intervention with five key stakeholder groups (council staff, managers and human resources, employee healthcare, students, and lecturers). Three rounds of focus groups explored the ‘problem’, the possible solutions, the process, and the content. Themes were taken from each of these focus groups and the similarities and differences were analysed. This analysis and subsequent synthesis with the evidence base created potential intervention models, which were discussed and refined with the stakeholder groups. Intervention. The proposed intervention is focused on providing evidence informed biopsychosocial support for work-relevant back pain, based on identifying obstacles and solutions to improve coping with back health at work. An onboarding workshop challenges positively their thinking around back pain and work. This is followed by up to three 1:1 sessions that support the individual to identify work-relevant back health goals and agree a plan to achieve them using techniques to facilitate behaviour change. Conclusion. The intervention is evidence informed and aims to address the prioritised needs of the stakeholders. Conflicts of interest. No conflicts of interest. Sources of funding. National Health Service Education

Knee osteoarthritis (KOA) diagnosis is based on symptoms, assessed through questionnaires such as the WOMAC. However, the inconsistency of pain recording and the discrepancy between joint phenotype and symptoms highlight the need for objective biomarkers in KOA diagnosis. To this end, we study relationships among clinical and molecular data in a cohort of women (n=51) with Kellgren-Lawrence grade 2–3 KOA through Support Vector Machine (SVM) and a regulation network model (RNM). Clinical descriptors (i.e., pain catastrophism (CA); depression (DE); functionality (FU); joint pain (JP); rigidity (RI); sensitization (SE); synovitis (SY)) are used to classify patients. A Youden's test is performed for each classifier to determine optimal binarization thresholds for the descriptors. Thresholds are tested against patient stratification according to baseline WOMAC data from the Osteoarthritis Initiative, and the mean accuracy is 0.97. For our cohort, the data used as SVM inputs are KOA descriptors, synovial fluid (SL) proteomic measurements (n=25), and transcription factors (TF) activation obtained from RNM [2] stimulated with the SL measurements. The relative weights after classification reflect input importance. The performance of each classifier is evaluated through AUC-ROC analysis. The best classifier with clinical data is CA (AUC = 0.9), highly influenced by FU and SE, suggesting that kinesophobia is involved in pain perception. With SL input, leptin strongly influences every classifier, suggesting the importance of low-grade inflammation. When TF are used, the mean AUC is limited to 0.608, which can be related to the pleomorphic behaviour of osteoarthritic chondrocytes. Nevertheless, FU has an AUC of 0.7 with strong importance of FOXO downregulation. Though larger and longitudinal cohorts are needed, this unique combination of SVM and RNM shall help to map objectively KOA descriptors. Acknowledgements: Catalan & Spanish governments 2020FI_b00680; STRATO-PID2021126469ob-C21-2, European Commission (MSCA-TN-ETN-2020-Disc4All-955735, ERC-2021-CoG-O-Health-101044828). ICREA Academia

Introduction. Clinical decision support tools are software that match the input characteristics of an individual patient to an established knowledge base to create patient-specific assessments that support and better inform individualized healthcare decisions. Clinical decision support tools can facilitate better evidence-based care and offer the potential for improved treatment quality and selection, shared decision making, while also standardizing patient expectations. Methods. Predict+ is a novel, clinical decision support tool that leverages clinical data from the Exactech Equinoxe shoulder clinical outcomes database, which is composed of >11,000 shoulder arthroplasty patients using one specific implant type from more than 30 different clinical sites using standardized forms. Predict+ utilizes multiple coordinated and locked supervised machine learning algorithms to make patient-specific predictions of 7 outcome measures at multiple postoperative timepoints (from 3 months to 7 years after surgery) using as few as 19 preoperative inputs. Predict+ algorithms predictive accuracy for the 7 clinical outcome measures for each of aTSA and rTSA were quantified using the mean absolute error and the area under the receiver operating curve (AUROC). Results. Predict+ was released in November 2020 and is currently in limited launch in the US and select international markets. Predict+ utilizes an interactive graphical user interface to facilitate efficient entry of the preoperative inputs to generate personalized predictions of 7 clinical outcome measures achieved with aTSA and rTSA. Predict+ outputs a simple, patient-friendly graphical overview of preoperative status and a personalized 2-year outcome summary of aTSA and rTSA predictions for all 7 outcome measures to aid in the preoperative patient consultation process. Additionally, Predict+ outputs a detailed line-graph view of a patient's preoperative status and their personalized aTSA, rTSA, and aTSA vs. rTSA predicted outcomes for the 7 outcome measures at 6 postoperative timepoints. For each line-graph, the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient-satisfaction improvement thresholds are displayed to aid the surgeon in assessing improvement potential for aTSA and rTSA and also relative to an average age and gender matched patient. The initial clinical experience of Predict+ has been positive. Input of the preoperative patient data is efficient and generally completed in <5 minutes. However, continued workflow improvements are necessary to limit the occurrence of responder fatigue. The graphical user interface is intuitive and facilitated a rapid assessment of expected patient outcomes. We have not found the use of this tool to be disruptive of our clinic's workflow. Ultimately, this tool has positively shifted the preoperative consultation towards discussion of clinical outcomes data, and that has been helpful to guide a patient's understanding of what can be realistically achieved with shoulder arthroplasty. Discussion and Conclusions. Predict+ aims to improve a surgeon's ability to preoperatively counsel patients electing to undergo shoulder arthroplasty. We are hopeful this innovative tool will help align surgeon and patient expectations and ultimately improve patient satisfaction with this elective procedure. Future research is required, but our initial experience demonstrates the positive potential of this predictive tool

Aims

To investigate the extent of bone development around the scaffold of custom triflange acetabular components (CTACs) over time.

Purpose/Background. More than 20 million UK citizens have MSK conditions, and post-pandemic the backlog awaiting access to MSK services has increased. The most prevalent MSK condition is low back pain (LBP), and getUBetter has been recommended by NICE as one of five digital health technologies for helping manage LBP. Purpose: Evaluate impact of getUBetter on a community MSK waiting list. Methods/Results. Mixed methods approach used. All patients on community MSK waiting list sent a postal invite for getUBetter. Number of downloads and frequency of use recorded, and users emailed questionnaire exploring outcomes and satisfaction. Rate users removed themselves from the waiting list compared with non-users. Of 14,500 invitations, 657(4.5%) patients downloaded getUBetter, 395(60.1%) used it once and 138(21%) ≥3 times. Seventeen (7%) of 239 patients canvassed responded to questionnaire, 17% reported improved pain, 21% reported improved confidence and had been helped back to work. Twenty-five percent better understood their condition and 43% needed no other treatment. Seventy-five percent were critical of limited content, with chronic osteoarthritis mentioned. 69.6% of users removed themselves from the waiting list. This was 29.6% above the rate for non-users. Conclusion. Sending postal invites for getUBetter to a MSK waiting list yielded limited uptake. However, despite some criticisms, patients using it reported improved pain, early return to usual activities, and improved confidence in self-management. Some patients recovered without the need for additional support and getUBetter shows some potential for reducing a MSK waiting list. Clearly further work is required to explore methods to increase patient uptake and maximise impact. Conflicts of interest. None. Sources of funding. None

Introduction: Anterior cruciate ligament (ACL) rupture leads to biomechanics disturbances of the knee joint which are reflected also in the plantar supports. Our hypothesis is that a redistribution of the sole bilateral charges will be produced to allows the feet to get a new control system to compensate ACL rupture. The aim of this research is to study the plantar support pressures disturbances in patients with ACL rupture before operation. Material and Methods: We analyzed the plantar pressure distribution in two populations: Group A: 39 males of 37 years average age (21–49 y.o), previous surgery of isolated ACL rupture, excluding patients with meniscal tear or serious cartilage damage, contralateral lesions and knee previous surgery as well. Group B (control group): 37 healthy males of 31 years average age (21–40 y.o) without any musculoskeletal disorders. We performed physical examination and walking through a pedography plate (Emed, Novel Munich, Germany). We studied global plantar support (pressure, forces and areas) of each foot and also divided each foot into six parts. Data obtained was compared between group A, patients (healthy leg and ACL rupture leg) and group B (control group). Statistical analysis was performed with a non-parametric Wilcoxon test. Results: Group A (healthy leg and ACL rupture leg) total support area of both feet were statistically superior than Group B total support area (p< 0,019 and p< 0,005 respectively). Evenly midfoot total support area was superior in Group A that in Group B, as well as midfoot force support (p< 0.089). Group A midfoot pressure was higher in ACL rupture leg than in healthy leg (p< 0.007) and it was also higher to the one obtained for group B (p< 0.046). Evenly the anterior-external region of Group A, healthy leg got the highest pressure (p< 0.076), followed by Group A, ACL rupture leg (p< 0.022) and finally Group B. Group B anterior-internal pressure was statistically superior to Group A, ACL rupture leg (p< 0.049) followed by Group A, healthy leg (p=0.022). During foot takeoff, first toe pressures were higher in Group B compared to Group A (p< 0.076). Conclusion: ACL rupture shows differences in plantar support pressures distribution of both legs (ACL rupture leg and healthy leg) compared with a control population. The injured leg seeks balance decreasing heel support and increasing the contact surfaces between floor, midfoot and forefoot

Total hip replacement procedures are among the most frequent surgical interventions in all industrialized countries. Although it is a routine operationliterature reports that important parameters regarding for example cup orientation and leg length discrepancy often turn out to be not satisfying after surgery. This paper presents a novel concept to improve the reproducibility and accuracy for implantation of cup and stem prosthesis at exactly the desired locations. Existing computer- based commercial products either offer software solutions for just pre-operative planning, or imageless navigation systems that are only used during surgery in the operating theatre. The innovation of our approach is based on an integrated computer-assisted solution that combines pre-operative planning and intra-operative navigation to support THR procedures. The software for pre-operative planning can process both, 3D CT images and standard 2D x-ray images. A custom-built navigation system using optical 3D localizing technology has been developed to transfer planning results to the OR. The main objective of our approach is to implant the artificial joint in a way to restore the natural anatomy of the joint before surgery as close as possible, or with exactly planned modifications. In particular, cup inclination, cumulative anteversion of cup and stem, CCD angle and lateral offset, centre of rotation, leg length discrepancy, and joint range of motion are considered. It is not necessary to determine numerical values for all of these parameters because our approach uses a unique procedure to record the natural anatomical situation by combining pre-operative planning and intra-operative navigation, and subsequently supports implantation of the prosthesis components by surgical navigation in order to restore this situation. In case planar 2D x-ray images are used for pre-operative planning accurate scaling of these images is a prerequisite for exact determination of relevant parameters. The patient-specific scaling factor depends on the distance of the hip joint rotation centre from the x-ray detector or film. We have designed a low-cost localization system to be mounted close to the x-ray apparatus. It localizes the 3D position of the rotation centre by small motions of the leg and eliminates uncertainties of conventional methods that are caused by improper positioning of a calibration body. Easy and robust setup and application have been key objectives for the development of our custom-built navigation system. Acquisition of intraoperative parameters for example includes the determination of the acetabular centre axis by localizing selected landmarks at the acetabular rim. Intra-operative parameters are combined with pre-operative parameters without needing sophisticated matching procedures with the pre-operative images. A preliminary surgical workflow that will be detailed in the conference presentation has been designed for evaluation of the concept using sawbones models. Based on the promising results of our laboratory tests we have started to prepare first clinical experiments in close cooperation with surgeons

Introduction. Locking plates can provide greater stability than conventional plates; however, reports revealed that fractures had a high incidence of failure without medial column support; the mechanical support of medial column could play a significant role in humeral fractures. Recent studies have demonstrated the importance of intramedullary strut in proximal humeral fracture fixation, the relationship to mechanical stability and supporting position of the strut remain unclear. The purpose of this study was to evaluate the influence of position of the intramedullary strut on the stability of proximal humeral fractures using a locking plate. Materials and methods. Ten humeral sawbone (Synbone) and locked plates (Synthes, cloverleaf plate), with and without augmented intramedullary strut (five in each group) for proximal humerus fractures, were tested using material testing machine to validate the finite element model. A 10 mm osteotomy was performed at surgical neck and a strut graft (10 cm in length) was inserted into the fracture region to lift the head superiorly. Each specimen was statically tested at a rate of 5 mm/min until failure. To build the finite element (FE) model, 64-slices CT images were converted to create a 3D solid model. The material properties of screws and plates were modeled as isotropic and linear elastic, with an elastic modulus of 110 GPa, (Poisson's ratio, n=0.3). The Young's moduli of cortical and cancellous bones were 17 GPa and 500 MPa (n=0.4), respectively. Three alter shifting toward far cortex by 1, 2, and 3 mm in humeral canal were installed in the simulating model. Results and discussion. The test result showed stiffness for only locked plate was 149.2±21.3 N/mm; and the plating combined with an intramedullary strut was 336.5±50.4 N/mm. On average, the stiffness was increased by 2.2 times in the augmented fixation relative to the only locking plate fixation. The finite element analytical results showed stiffness of 162 N/mm for fixation without strut, and 372 N/mm for those with strut augmentation. The stiffness between experiment and FE analysis agreed in 8.6% for the only locking plate case; and agreed in 10.5% for the case fixed with intramedullary strut. FE analysis showed the stability of construct increased 7%, 11% and 20% as the strut shift by 1, 2, and 3 mm, respectively. Gardner (2007) reported the importance of mechanical support at the medial region for maintenance of reduction when proximal humerus fracture treated with locking plates. Conclusion. The intramedullary strut may provide superior stability than the only locking plate fixation. The FE model provides a useful implement to find the optimal configuration of plate fixation. Acknowledgements. All authors thank the funding support from National Science Council (NSC 102-2628-B-650-001) and E-Da Hospital (EDPJ1020027)

Abstract

Abstract

Purpose of the study: We have tried to produce a new acetabular ring in order to obtain an early stability of cemented cup for acetabular protrusion in R.A. In this presentation, we intend to introduce this new support ring and report these results. Materials and methods: The new support ring with double-hook we produced was made of pure titanium, and has eight screw holes in medial side and two screw holes in superolateral side. Size variation of this ring comprises 40mm, 42mm, 46mm, 48mm and 50mm in inner diameter. Width of the hook is 10.05mm and its thickness is 1.19mm. Hook length is 33.5mm. After the remaining bone defect is packed with morselizd and mushed allograft bone, proper support ring with double hook is selected. Straight portions of double hook are bent in order to fit to acetabular shape after bone grafts. If good fitting is achieved, this support ring was fixed to the acetabulum with three to five screws. Total hip arthroplasty with this support ring was performed in ten patients with eleven hips. Three cases were in male and seven in female. The age at surgery ranged from 46 to 73 years old with an average of 59.8 years. Results: Setting angle of support ring ranged from 40 to 50 degrees with an average of 43.7 degrees. Follow-up period was from one year to three years with an average of two years one month. No loosening was encountered and no migration of support ring and cup was visualized on radiological findings. JOA(Japanese Orthopaedic Association) hip score which was adopted for clinical evaluation was 31.3+/−10.2 before surgery and 70.1+/−8.5 after surgery. Discussion: Various types of reinforcement ring have been used with or without bone grafts for acetabular protrusion. I had prefered Ganz ring among them. Bending a hook of Ganz ring, however, is not easy as its hook portion is slightly thick. Accordingly, setting angle of the ring is often apt to be acute as it must be fitted to acetablualr shape. In superior cortical defect of the acetabulum, hook length is often insufficient because a hip center of the ring is in high position. Therefore, it is sometimes impossible to hook acetabular notch. We produced a new support ring with double-hook in order to solve these problems. As the hook was thinner in the new ring than in Ganz ring, it was easier to bend the hook. As the hook of of the new ring was longer than that of Ganz ring, it was possible to hook acetabular notch in spite of high hip center. Setting angle of the new rings was less than 50 degrees. Radiological findings and clinical results were good though follow-up period was short

Between 1980 and 2000, 63 support rings were used in the management of acetabular deficiency in a series of 60 patients, with a mean follow-up of 8.75 years (2 months to 23.8 years). There was a minimum five-year follow-up for successful reconstructions. The indication for revision surgery was aseptic loosening in 30 cases and infection in 33. All cases were Paprosky III defects; IIIA in 33 patients (52.4%) and IIIB in 30 (47.6%), including four with pelvic dissociation. A total of 26 patients (43.3%) have died since surgery, and 34 (56.7%) remain under clinical review. With acetabular revision for infection or aseptic loosening as the definition of failure, we report success in 53 (84%) of the reconstructions. A total of 12 failures (19%) required further surgery, four (6.3%) for aseptic loosening of the acetabular construct, six (9.5%) for recurrent infection and two (3.2%) for recurrent dislocation requiring captive components. Complications, seen in 11 patients (18.3%), included six femoral or sciatic neuropraxias which all resolved, one grade III heterotopic ossification, one on-table acetabular revision for instability, and three early post-operative dislocations managed by manipulation under anaesthesia, with no further instability. We recommend support rings and morcellised bone graft for significant acetabular bone deficiency that cannot be reconstructed using mesh