Aims. Reimers migration percentage (MP) is a key measure to inform decision-making around the management of hip displacement in cerebral palsy (CP). The aim of this study is to assess validity and inter- and intra-rater reliability of a novel method of measuring MP using a smart phone app (HipScreen (HS) app). Methods. A total of 20 pelvis radiographs (40 hips) were used to measure MP by using the HS app. Measurements were performed by five different members of the multidisciplinary team, with varying levels of expertise in MP measurement. The same measurements were repeated two weeks later. A senior orthopaedic surgeon measured the MP on picture archiving and communication system (PACS) as the gold standard and repeated the measurements using HS app. Pearson’s correlation coefficient (r) was used to compare PACS measurements and all HS app measurements and assess validity. Intraclass correlation coefficient (ICC) was used to assess intra- and inter-rater reliability. Results. All HS app measurements (from 5 raters at week 0 and week 2 and PACS rater) showed highly significant correlation with the PACS measurements (p < 0.001). Pearson’s correlation coefficient (r) was constantly over 0.9, suggesting high validity. Correlation of all HS app measures from different raters to each other was significant with r > 0.874 and p < 0.001, which also confirms high validity. Both inter- and intra-rater reliability were excellent with ICC > 0.9. In a 95% confidence interval for repeated measurements, the deviation of each specific measurement was less than 4% MP for single measurer and 5% for different measurers. Conclusion. The HS app provides a valid method to measure hip MP in CP, with excellent inter- and intra-rater reliability across different medical and allied health specialties. This can be used in hip surveillance programmes by interdisciplinary measurers. Cite this article: Bone Jt Open 2023;4(5):363–369

Introduction. With advances in mobile application, digital health is being increasingly used for remote and personalised care. Patient education, self-management and tele communication is a crucial factor in optimising outcomes. Aims. We explore the use of a smartphone app based orthopaedic care management system to deliver personalised surgical experience, monitor patient engagement and functional outcomes of patients undergoing knee arthroplasty. Results. Over a 12-month period, 124 patients listed for knee arthroplasty were offered access to the app. Average patient age was 65.4 years (range 49 to 86). 13(10.4%) patients were over 80 years. Compliance with app usage was 86.4%. Compliance with post-operative exercises increased following a message through the app. The mean Oxford knee score improved from a pre-op value of 17 to 35 at a mean follow-up of 6 months. Mean numeric rating scale pain score reduced from 7 pre-operatively to 3 at the latest follow-up. 58 patients (46.7%) used the communication feature on the app (text messages, photos, video consultations), reducing telephone calls and patient foot fall in the hospital. Patient satisfaction with the app was very high. Conclusion. We found the virtual care system to be effective in providing patient education, prehabilitation and post-operative rehabilitation along with being an effective channel of communication between patients and the hospital team. Patient satisfaction and compliance was very high

Background. Mobile apps have shown promise in helping people to self-manage conditions like chronic low back pain (CLBP). However, it is unclear who benefits most, why, and under what circumstances. This limits our understanding of how to maximize the potential of mobile app technology. Aim. This study aimed to test and refine programme theories about how mobile apps support people to self-manage CLBP in a real-world setting. The theories were based on a previously published realist review. Methods. A realist evaluation was conducted using one-to-one realist interviews by telephone with participants who had used the Curable app to self-manage their CLBP for three months. The interviews were guided by programme theories from the realist review. Analysis of the interviews used abductive and retroductive logic to create chains of inferences, which were then developed into context-mechanism-outcome configurations (CMOCs). These CMOCs offered causal explanations about who might benefit from a mobile app to self-manage CLBP, why and in what circumstances. Results. Ten interviews were conducted (nine with people with CLBP who trialled the app and one with a founding member of Curable LLC). Twenty CMOCs were created that identified key mechanisms such as agency, control and reassurance that interact with contextual factors such as acceptance, internal capacity, and a biopsychosocial approach to pain management. These factors influence whether a person with CLBP will benefit from a mobile app for self-management. Conclusions. Twenty CMOCs were created to support three programme theories centering around concepts of empowerment, burden of care, and timing. Conflicts of interest. None. Sources of funding. R Hunter's work was supported by the Inverness and Highland City-Region Deal Studentship Award [2018]. Presented at: 13th Congress of the European Pain Federation (EFIC), September 2023, Budapest, Hungary

Purpose and Background. Clinical practice guidelines (CPGs) recommend self-management for low back pain (LBP). Our recent narrative review on self-management needs revealed a consensus with respect to the critical components of self-management interventions. With mobile health advancements, apps offer innovative support for LBP management. This study aims to identify current apps for the self-management of LBP, assessing them for their quality, intervention content, theoretical approaches, and risk management approaches. Methods and Results. We identified 69 apps for LBP self-management from a systematic search in the UK iTunes and Google Play stores. The most recommended interventions are muscle stretching (n=51, 73.9%), muscle strengthening (n=42, 60.9%), and core stability exercises (n=32, 46.4%). The average MARS (SD) overall score for the included apps was 2.4 (0.44) out of a possible 5 points, with the engagement and information dimension scoring the lowest at 2.1. In terms of theoretical and risk management approaches, no apps offered a theoretical care model and all failed to specify the age group targeted; only one (1.4%) provided a tailored care approach; 18 (26.1%) included intervention progression; and 11 (15.9%) reported management safety checks. Conclusion. This study shows that app developers generally select interventions endorsed by CPGs. However, the application of a biopsychosocial care model is not being considered. Most of them are of low quality, lacking theoretical approaches to care and consideration of associated risks. It is essential to involve clinicians and patients in developing LBP self-management apps to improve the quality and related approach. Conflicts of interest. None. Sources of funding. No funding obtained. This study has been published in JMIR mHealth and uHealth

Recently, several smartphone applications (apps) have been developed and validated for ankle ROM measurement tools like the universal goniometer. This is the first innovative study introduces a new smartphone application to measure ankle joint ROM as a remote solution. This study aimed to assess the correlation between smartphone ROM and universal goniometer measurements, and also report the evaluation of the DijiA app by users. The study included 22 healthy university students (14F/8M; 20.68±1.72 years) admitted to Yeditepe University. Fourty four feet was measured by both the universal goniometer (UG) and DijiA app. The datas were analyzed through using the intraclass correlation coefficient (ICC). The DijiA app was evaluated by usability testing with representative users. Pearson correlation coefficient test showed moderate correlation between the DijiA and UG for dorsiflexion (DF) and plantar flexion (PF) measurements (Pearson correlation coefficient: r=0.323, for DF; r=0.435 for PF 95% confidence interval). The application usability was found as high with 76.5 average score and users liked it. The DijiA app may be a more convenient and easy way to measure ankle DF and PF-ROM than UG. It can be used to evaluate ROM in clinical practice or home using as a personal smartphone

Aim. Early discharge of patients after joint arthroplasty leaves patients responsible for monitoring their postoperative wound by themselves. This might result in a delayed presentation of postoperative complications. The use of a mobile woundcare app by patients after arthroplasty might result in (1) earlier report of complications, (2) an increase in patient satisfaction and (3) insight in the incidence and duration of postoperative wound leakage. Therefore, the ease of use and perceived usefulness of using a postoperative mobile woundcare app in patients after joint arthroplasty was investigated. Method. A cohort study was conducted in 2017 in 2 Dutch Hospitals. Eligible cases were all consecutive patients that received an arthroplasty and who owned a smartphone. During the first 30 postoperative days, patients filled in daily reviews of their wound and took a photo of the wound. Based on the review, an underlying algorithm calculated daily a score that prompted a mobile alert if needed, which advised patients to contact the hospital. Patients filled in a form on day 30 and day 90 in order to document occurrence of any postoperative wound complication. On day 15 and 30, patients were requested to fill in a questionnaire evaluating the perceived usefulness and the ease of use of the App. Results. Of 127 eligible patients, 30 (24%) did not have a smartphone. Of the remaining 97 patients, 69 patients (71%) were included. Median age was 68 years (range 33–90 years). Forty-one patients (59.4%) used the app until day 30. On average, the app was used for 19.1 days (95% CI 16.6–21.5). Nine patients (13.0%) stopped using the app directly after the first or second day. The overall mean grade on a scale of 1 (strongly disagree) to 5 (strongly agree) was 4.2 for ease of use and 4.1 for perceived usefulness. The scores on day 30 were comparable to day 15. One patient (1.4%) developed a prosthetic joint infection. Conclusions. The introduction of a mobile woundcare app resulted in a high overall satisfaction rate with respect to ease of use and perceived usefulness. Daily use of the app did not lead to more stress. Currently, a nationwide cohort study is set up to implement the mobile woundcare app in Dutch hospitals to improve patient care. The app will then also be used to investigate the correlation between duration of postoperative wound leakage after joint arthroplasty and the development of prosthetic joint infection

Background. The duration and extent of postoperative wound leakage after joint arthroplasty in patients with or without a complicated course, like a prosthetic joint infection (PJI), is currently unknown. Adequate differentiation between normal postoperative wound leakage and wound leakage due to a postoperative PJI is important and prevents unnecessary surgical procedures. We investigated the association between postoperative wound leakage and development of PJI in patients who used a previously developed mobile wound care app. Methods. A multicenter, prospective cohort study with patients aged 18 years or older after primary implantation or revision of a total joint arthroplasty. During 30 post-operative days after arthroplasty, patients recorded their wound status in the woundcare app. An algorithm calculated a daily score from imputed data. If the daily score exceeded a predefined threshold, the patients received an alert that advised them to contact their physician. Results. Of 1020 included patients from 11 centers, 14 patients developed a PJI. Of 1006 patients without PJI, any form of postoperative wound leakage occurred in 51%, 12%, 7% and 3% during the 1. st. , 2. nd. , 3. rd. and 4. th. postoperative week, respectively. Median duration of wound leakage was eight days (IQR 3.5–12.5) for patients with PJI and two days (IQR 0–4) for patients without PJI (p <0.001). In total, 498 (49%) patients received 2589 alerts. Receiving an alert was not predictive for the development of a PJI. The odds ratio for a PJI was higher in patients with wound leakage compared to patients without wound leakage: OR 1.76 (0.59–5.29), OR 45.42 (10.04–205.53), OR 16.76 (3.68–76.28) and OR 18.09 (1.59–205.66) in the 1. st. , 2. nd. , 3. rd. and 4. th. postoperative week, respectively. Conclusion. In patients who received a knee or hip arthroplasty, the odds ratios for PJI were significantly increased in patients with postoperative wound leakage. However, the high absolute number of patients with wound leakage and no PJI showed that wound leakage alone is not a sensitive, i.e. discriminative, indicator to guide the decision whether to reoperate patients for a suspected PJI. The abstract was submitted on behalf of the Woundcare app study group: H.M.J. van der Linden, Leiden University Medical Centre; D. Broekhuis, Leiden University Medical Centre; M. de Jong, Leiden University Medical Centre; M.R. Benard, Alrijne Hospital; A.P. Wassenaar, Alrijne hospital; A.S.B. Mol, Alrijne Hospital; M. Rutgers, Reinier Haga Orthopedic Center; J.Pasma, Reinier Haga Orthopedic Center; R. Bazuin, Reinier Haga Orthopedic Center; N. Mathijssen, Reinier Haga Orthopedic Center; C.E. Van Der Wijngaart, Onze Lieve Vrouwe Gasthuis; N.W. Willigenburg, Onze Lieve Vrouwe Gasthuis; M.E. Van Der Hoorn, Onze Lieve Vrouwe Gasthuis; B. Dijkstra, Medical Center Leeuwarden; L.D. De Jong, Rijnstate Hospital; H. Haan, University Medical Centre Groningen; M. Stevens, University Medical Centre Groningen; M. Reijman, Erasmus Medical Centre Rotterdam; H. Hoogeboom, Nijsmellinghe Medical Centre; C. Meijer, Park Medical Centre + all authors listed above this article

In light of recent regulatory initiatives, medical devices now require additional clinical evidence to prove their safety and efficacy. At the same time, patients' own assessment of their devices' function and performance has gained in importance. The collection of these data allows for a more comprehensive picture of clinical outcomes and complications following total knee arthroplasty (TKA). These trends have led researchers to search for new methods of acquiring, interpreting and disseminating patient-reported outcome measurements (PROMs). The current study assesses the feasibility of a digital platform for collecting PROMs that was recently adapted for TKA patients. It sought to determine patient engagement, survey completion rates, and satisfaction with this platform. Eighty-two patients (mean age, 63.7 years, 59% females) scheduled for TKA were enrolled from one US and six UK sites between January 12, 2018 and April 30, 2018. Patients were supplied with a mobile application (app) that collects a variety of PROMs, including four domains based on the Patient-Reported Outcome Information System (PROMIS™): physical function, depression, pain interference and pain behavior. The platform electronically administers questionnaires using computer-adaptive tests (CATs), which reduce the burden on patients by tailoring follow-up questions to account for their previous answers. Satisfaction with the app was assessed in subset of patients who evaluated its ease-of-use (n=45), likelihood that they would recommend it to family/friends (n=35), and whether they successfully used the information it provided during their recovery (n=31). These scores were taken on a 1 to 10 (worst to best) scale. Patients demonstrated regular engagement with the platform, with 73% using the app at least once a week. Weekly engagement remained high throughout the seven-week post-operative period (Figure 1). There was a 69% completion rate of all PROMIS™ CAT surveys during the study. The four PROMIS™ CAT domains had similar survey completion rates (Figure 2). The subset of patients queried regarding their satisfaction with the app gave it favorable mean scores for ease-of-use (8.8), likelihood to recommend to a family member or friend (8.1), and their success at using its information to improve their recovery (7.4). Initial results support this digital platform's potential for successfully and efficiently collecting large volumes of PROMs. Patients reported high levels of engagement and satisfaction. For any figures or tables, please contact authors directly

Background to the study:. The use of Patient Reported Outcome Measures (PROMs) is being increasingly advocated but data are still being collected using paper systems. This is costly and environmentally challenging. New innovations are required to balance the challenges of capturing PROM data while considering budgets, and access to IT, and patient choice. Purpose of the study:. To develop and test a mobile phone and web app for collecting patient reported outcomes about musculoskeletal symptoms. Methods:. The content of the app was developed following qualitative work with patients and clinicians, and a review of measurement properties of different PROMs. Early versions of the app underwent α- and β-testing to identify issues with functionality. The PROM app was pilot-tested to assess feasibility, responsiveness, and test-retest reliability of the PROMs. The pilot version of the app contained demographic data, the Roland Morris Disability Questionnaire (RMDQ), the Bournemouth Questionnaire, and Visual Analogue Scale for pain. At follow-up additional questions exploring patient satisfaction and experience of care, plus a transition question were asked. Results:. A total of 517 patient codes were allocated. Completed datasets were gathered from patients (N=92) potentially indicating issues with acceptability and feasibility. Data analysis indicated good completion of questions. The RMDQ appeared to be largely redundant in this patient population and was removed in the final version of the app. Conclusion:. The app performed well when used by participants. Support is required for practitioners and patients to implement this electronic data capture system

Tracked B-mode ultrasound (US) potentially provides a non-invasive and radiation-free alternative to percutaneous pointer digitization for intra-operative determination of the anterior pelvis plane (APP). However, most of the published approaches demand a direct access to the corresponding landmarks, which can only be presumed for surgical approaches with the patient in supine position. In order to avoid any change of the clinical routine for total hip arthroplasties (THAs), we propose a new method to determine the pelvic orientation, which could be performed in lateral position. Our proposed method is based on the acquisition of ultrasound images of the ipsilateral hemi-pelvis, namely the posterior superior iliac spines (PSISs) and iliac crest region. The US images are tracked by a navigation system and further processed to extract three-dimensional point clouds. As only one side of the pelvis is accessible, we estimate the symmetry plane (midsagittal plane) of the pelvis based on additionally digitized bilateral anterior superior iliac spine (ASIS) landmarks. This symmetry plane is further used to mirror the ipsilateral US-derived points to the contralateral side of the pelvis and to register and instantiate a pelvic SSM constructed from 30 CT-scans. The proposed registration method was evaluated using two plastic pelvis models and two cadaveric pelvises together with special custom-made silicone phantoms to simulate the missing soft-tissue. In each trial, the required data were collected with the pelvis rigidly fixed in lateral decubitus position together with ground truth APP landmarks. A registration error of 3.48° ± 1.10° was found for the anteversion angle, while the inclination angle could be reconstructed with a mean error of 1.26° ± 1.62°. The performed in-vitro experiments showed reasonably good results, taking the sparsity of the input point clouds into consideration

Background

Smartphones are now a ubiquitous presence within the modern healthcare setting. Uses such as internet, database software and storage of medical textbooks, all contribute to the clinical value of the devices. Within orthopaedics, transmission of digital images via smartphones is now routinely used to obtain instant second opinions of trauma radiographs. However questions remain as to whether smartphone image quality is sufficient for primary diagnosis and secondary consultation

Aims. This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated. Methods. A total of ten orthopaedic surgeons classified 20 cases of PJI based on the PJI-TNM classification. Subsequently, the classification was re-evaluated using the PJI-TNM app. Classification accuracy was calculated separately for each subcategory (reinfection, tissue and implant condition, non-human cells, and morbidity of the patient). Fleiss’ kappa and Cohen’s kappa were calculated for interobserver and intraobserver reliability, respectively. Results. Overall, interobserver and intraobserver agreements were substantial across the 20 classified cases. Analyses for the variable ‘reinfection’ revealed an almost perfect interobserver and intraobserver agreement with a classification accuracy of 94.8%. The category 'tissue and implant conditions' showed moderate interobserver and substantial intraobserver reliability, while the classification accuracy was 70.8%. For 'non-human cells,' accuracy was 81.0% and interobserver agreement was moderate with an almost perfect intraobserver reliability. The classification accuracy of the variable 'morbidity of the patient' reached 73.5% with a moderate interobserver agreement, whereas the intraobserver agreement was substantial. The application of the app yielded comparable results across all subgroups. Conclusion. The PJI-TNM classification system captures the heterogeneity of PJI and can be applied with substantial inter- and intraobserver reliability. The PJI-TNM educational app aims to facilitate application in clinical practice. A major limitation was the correct assessment of the implant situation. To eliminate this, a re-evaluation according to intraoperative findings is strongly recommended. Cite this article: Bone Joint Res 2024;13(1):19–27

To our knowledge, we are the only centre in the UK where Achilles tenotomies (TA) for CTEV Ponseti correction are performed in outpatient clinic under local anaesthetic by an Advanced Physiotherapy Practitioner (APP) in orthopaedics. This study aims to present the outcomes and safety of this practice. Retrospective analysis of cases of idiopathic CTEV undergoing Ponseti correction January 2020 to October 2022. Demographic data: Pirani score and number of casts before boots and bar. Patients were divided into five groups: Group 1: TA performed by an Orthopaedic consultant under general anaesthetic (GA) in theatre. Group 2: TA performed by an Orthopaedic consultant under local anaesthetic (LA) in theatre. Group 3: TA performed by APP under GA in theatre. Group 4: TA performed by APP under LA in theatre. Group 5: TA performed by an APP under LA in outpatient clinic. Complications recorded: revision TA, infection, neurovascular injury or need for re-casting. Mean follow up 18 months. 45 feet included. Mean Pirani score 5.5, age started casting 33 days and total number of casts 6. No significant difference in demographic details between groups. 6, 4, 20, 5 and 10 tenotomies were performed in groups 1, 2, 3, 4, and 5 respectively. Complications were 1 revision tenotomy from group 2, one from group 4 and 1 renewal of cast from 3. This study demonstrates that TAs performed in outpatient clinic under LA by an APP is safe and feasible. No increase in complications were observed compared to TAs performed by orthopaedic consultants

Introduction. Orthopedics is experiencing a significant transformation with the introduction of technologies such as robotics and apps. These, integrated into the post-operative rehabilitation process, promise to improve clinical outcomes, patient satisfaction, and the overall efficiency of the healthcare system. This study examines the impact of an app called Mymobility and intra-operative data collected via the ROSA® robotic system on the functional recovery of patients undergoing robot-assisted knee arthroplasty. Method. The study was conducted at a single center from 2020 to 2023. Data from 436 patients were included, divided into “active” patients (active users of Mymobility) and “non-active” patients. Clinical analyses and satisfaction surveys were carried out on active patients. The intra-operative parameters recorded by ROSA® were correlated with the Patient-Reported Outcome Measures (PROMs) collected via Mymobility. Result. Intra-operative data showed significant correlations with PROMs for the 48 active patients, highlighting the importance of parameters such as medial joint space and ligament laxity. No significant differences were observed between the sexes, but a positive correlation was detected between age and PROMs. The data analysis indicated that an increased medial joint space and reduced ligament laxity are associated with better PROMs. The adoption of Mymobility remained limited, with only 10% of patients fully utilizing the app. Critical factors have been identified to improve recruitment, engagement, and overall experience with the platform. Conclusion. The integration of technologies such as Mymobility and ROSA® in post-operative rehabilitation offers numerous advantages, including the objectification of data, active patient involvement, and personalized care. Challenges remain related to costs, patient compliance, and demographic limitations. Nevertheless, these technologies represent a milestone in modern peri-operative management, being able to improve clinical outcomes and the quality of care

Background. Scoliosis is described as a lateral spinal curvature exceeding ten degrees on radiograph with vertebral rotation. Approximately 80% of scoliosis presentations are adolescent idiopathic scoliosis (AIS). Current management for AIS in the UK occurs in Surgeon or Paediatrician-led clinics and can be conservative or surgical. The musculoskeletal assessment and triage of AIS appears well-suited to an advanced physiotherapist practitioner (APP) skill set. The aim of this service evaluation was to scope, develop, implement and evaluate a four-month pilot of an APP-led AIS triage pathway. Method and Results. Spinal Consultant deformity and scoliosis clinics were scoped and observed. Clinic inclusion criteria and a patient assessment form was developed. An APP AIS clinic was set up beside a consultant led clinic. All patients assessed were discussed with a spinal surgeon. Consultant and APP agreement (% of total), waiting times, surgical conversion, and patient satisfaction were reviewed. A clinical competency package was developed for training and development of APPs. A total of 49 patients were seen (20 sessions). Waiting list reduced from 10 weeks to 6 weeks. 45%(n=22) of new patients seen were diagnosed with AIS, 27% (n=6) were directly listed for surgery. Consultant/ APP percentage agreement was high for Cobb angle measurement (82%), management plans (90%), and further diagnostic requests (94%). There were no adverse events and high patient satisfaction levels (n=20), (100% Very satisfied or satisfied) were reported. Conclusion. APP-led AIS clinics can provide similar levels of management and assessment as Spinal Consultants with improved waiting times and high levels of satisfaction. Conflicts of interest: No conflicts of interest. Sources of funding: No funding obtained

Introduction. Advanced practice physiotherapists (APPs) manage the national low back and radicular pain pathway across the UK. A novel spinal APP-led same-day emergency care (SDEC) pathway in Nottingham, manages patients referred from community services and the emergency department (ED). Patients may attend ED in the belief their pain is due to sinister or ‘red flag’ pathology. Little data exists on prevalence of spinal ‘red flag’ pathologies within a secondary care setting. This paper aims to review the number of ‘red flag’ pathology identified by APP's on a same-day emergency care pathway. Methods. Retrospective data from 1 year of routinely collected information was extracted and analysed by two APPs. Counts were reported as a percentage of total patients seen on the SDEC unit over a one-year period and compared to nationally reported figures. A total of 2042 patients were assessed on the unit in 2021, of which, 293 (14%) had serious pathology identified. Patients were classified into type of serious pathology: myelopathy (126, 6.1%), fractures (72, 3.5%), cauda equine compression (40, 1.9%), infection (37, 1.8%), cancers (28, 1.3%), neurological conditions (14, 0.6%) and other (16, 0.8%) serious pathology. Conclusion. APP's working within an emergency pathway are highly likely to see and diagnose serious spinal pathology. The most common include cord or cauda equina compression, fractures, infection and cancers. Figures reported are slightly higher than previously documented. Knowledge and training to identify ‘red flags’ and robust pathways of escalation are essential in support of APP roles and services. Conflict of interest: No conflicts of interest. Sources of funding: No sources of funding

Introduction. A 6cm femoral gain requires 5-Y during normal growth, but only 6–8-W surgically (x30–40 faster). In lengthening surgery, losses of muscle force (MF) and circumferences (MC) are major. Recovery is long, preventing sports till bone fusion. Can we maintain MC and strength throughout the entire lengthening and how?. We monitored for over 30 years patients for muscle force (isokinetic), circumferences, activities (including sports) and food intake, and acted on the 5 principles of the Osteostasis. Materials & Methods. Over 750 femoral lengthening with Full WB Nails (FWBN) got Isokinetic testing (≧1991), circumferences measurements (≧2012; 20-15-10-5-0cm above patella, max-calf, mini/max-ankle), food intake (≧2012), using MyFitnessPal App (≧2016), gradually enforced. Preoperative training along with a daily post-operative training are supervised by our trainers. Recommendations for food intake and activities were provided. Patients noted on a specific App all parameters. Compliance was noted. Results. Instead of a traditional 7–9cm circumference loss for 8–10cm gains using Ex-fix or nails, with FWBN and our protocols, no MC loss could be noted in compliant pre-trained patients, intensive early post-op resistance training, high calory intake (M:>4200, F:>3000; 20–25% Proteins) and supplements (no fat pad increase). Bone fusion could be obtained at the end of lengthening or within short weeks (Healing Index down to 8D/cm). Non-compliant patients (or using morphine), lost weight and MC. Conclusions. Increasing by 8–10cm muscle length, even bilaterally, and maintaining MC during lengthening, is possible, with very fast bone fusion. It requires building up several hundred of grams of muscles. The ‘building up equation’ associating resistance bike from the early post-operative phase with sports, strong food intake with increased protein intake, and added supplements with no morphine medication, proved to boost circumferences and bone fusion. It induced fast recovery, walking and sports capacities

There is controversy regarding the effect of different approaches on recovery after THR. Collecting detailed relevant data with satisfactory compliance is difficult. Our retrospective observational multi-center study aimed to find out if the data collected via a remote coaching app can be used to monitor the speed of recovery after THR using the anterolateral (ALA), posterior (PA) and the direct anterior approach (DAA). 771 patients undergoing THR from 13 centers using the moveUP platform were identified. 239 had ALA, 345 DAA and 42 PA. There was no significant difference between the groups in the sex of patients or in preoperative HOOS Scores. There was however a significantly lower age in the DAA (64,1y) compared to ALA (66,9y), and a significantly lower Oxford Hip Score in the DAA (23,9) compared to PA(27,7). Step count measured by an activity tracker, pain killer and NSAID use was monitored via the app. We recorded when patients started driving following surgery, stopped using crutches, and their HOOS and Oxford hip scores at 6 weeks. Overall compliance with data request was 80%. Patients achieved their preoperative activity level after 25.8, 17,7 and 23.3 days, started driving a car after 33.6, 30.3 and 31.7 days, stopped painkillers after 27.5, 20.2 and 22.5 days, NSAID after 30.3, 25.7, and 24.7 days for ALA, DAA and PA respectively. Painkillers were stopped and preoperative activity levels were achieved significantly earlier favoring DAA over ALA. Similarly, crutches were abandoned significantly earlier (39.9, 29.7 and 24.4 days for ALA, DAA and PA respectively) favoring DAA and PA over ALA. HOOS scores and Oxford Hip scores improved significantly in all 3 groups at 6 weeks, without any statistically significant difference between groups in either Oxford Hip or HOOS subscores. No final conclusion can be drawn as to the superiority of either approach in this study but the remote coaching platform allowed the collection of detailed data which can be used to advise patients individually, manage expectations, improve outcomes and identify areas for further research

Introduction. Trabecular bone transmits loads to the cortical shell and is therefore most active in bone remodeling. This remodeling alters trabecular material strength thereby changing the bending stiffness. Accounting for trabecular material heterogeneity has been shown to improve empirical-µFEM correlations by allowing for more realistic trabecular bending stiffness. In µFEMs to reduce computation time, region averaging is often used to scale image resolution. However, region averaging not only alters trabecular architecture, but inherently alters the CT-intensity of each trabeculae. The effect of CT-intensity variations on computationally derived apparent modulus (E. app. ) in heterogenous µFEMs has not been discussed. The objectives of this study were to compare trabecular E. app. among i) hexahedral and tetrahedral µFEMs, ii) µFEMs generated from 32 µm, 64 µm, and 64 µm down-sampled from 32 µm µ-CT scans, and iii) µFEMs with homogeneous and heterogeneous tissue moduli. Methods. Fourteen cadaveric scapulae (7 male; 7 female) were micro-CT scanned at two spatial resolutions (32 µm & 64 µm). Virtual bone cores were extracted from the glenoid vault, maintaining a 2:1 aspect ratio, to create µFEMs from the 32 µm, 64 µm, and down-sampled 64 µm scans. Custom code was used to generate µFEMs with 8-node hexahedral elements (HEX8), while maintaining the bone volume fraction (BV/TV) of each HEX8 32 µm model (BV/TV=0.24±0.10). Each virtual core was also generated as a 10-node tetrahedral (TET10) µFEM. All µFEMs were given either a homogeneous tissue modulus of 20 GPa, or a heterogeneous tissue modulus scaled by CT-intensity. All FEMs were constrained with identical boundary conditions and compressed to 0.5% apparent strain. The apparent modulus of each model was compared. Results. Comparing error in mean E. app. , TET10 32 µm µFEMs with a homogeneous tissue modulus had an error of 7%, and a heterogeneous tissue modulus an error of 1%. Larger errors occurred for both down-sampled and scanned 64 µm µFEMs with both homogeneous and heterogeneous tissue moduli. The error in E. app. as a function of trabecular thickness (Tb.Th*) was larger for µFEMs generated from 64 µm scans, than the down-sampled 64 µm µFEMs. The errors were lowest for Tb.Th* greater than 0.225 mm and for µFEMs generated with heterogeneous tissue moduli. The error in E. app. as a function of volume fraction (BV/TV) was lowest above 0.225 for µFEMs with both homogeneous and heterogeneous tissue moduli and hexahedral and tetrahedral elements. Error was lower for the down-sampled 64 µm µFEMs versus scanned 64 µm µFEMs. DISCUSSION. This study compared the E. app. of linear isotropic µFEMs generated with hexahedral or tetrahedral elements from 32 µm, 64 µm, or down-sampled 64 µm µ-CT scans, with a homogeneous or heterogeneous tissue modulus. It was found that except at the highest spatial resolution, tetrahedral elements underestimate E. app. Down-sampling to half the original scan spatial resolution is not equivalent in E. app. to FEMs generated from scans at that spatial resolution, and both models underestimate the E. app. of the highest spatial resolution models. In general, accounting for trabecular material heterogeneity decreased errors in E. app.

Introduction. Density-modulus relationships are often used to map the mechanical properties of bone based on CT- intensity in finite element models (FEMs). Although these relationships are thought to be site-specific, relationships developed for alternative anatomic locations are often used regardless of bone being modeled. Six relationships are commonly used in finite element studies of the shoulder; however, the accuracy of these relationships have yet to be compared. This study compares each of these six relationships ability to predict apparent strain energy density (SED. app. ) in trabecular bone cores from the glenoid. Methods. Quantitative-CT (QCT) (0.625 mm isotropic voxels), and µ-CT scans (0.032 mm isotropic voxels) were obtained for fourteen cadaveric scapulae (7 male, 7 female). Micro finite element models (µ-FEMs) were created from 98 virtual ‘cores’ using direct conversion to hexahedral elements. Two µ-FEM cases were considered: homogeneous tissue modulus of 20 GPa, and heterogeneous tissue modulus scaled by CT intensity of the µ-CT images (196 models). Each µ- FEM model was compressively loaded to 0.5% apparent strain and apparent strain energy density (SED. app. ) was calculated. Additionally, each of the six density-modulus relationships were used to map heterogeneous material properties to co- registered QCT-derived models (588 models in total). The loading and boundary conditions were replicated in the QCT-FEMs and the SED. app. was calculated and compared to the µ-FEM SED. app. To account for more samples than donors, restricted maximum likelihood estimation (REML) linear regression compared µ-FEM SED. app. and QCT-FEM SED. app. for each relationship. Results. When considering comparisons between QCT-FEMs and µ-FEMs with a homogeneous tissue modulus, near absolute statistical agreement (Y=X) was observed between the µ-FEMs and the QCT-FEMs using the Morgan et al. (2003) pooled relationship. Not surprisingly, due to the similarity between the two relationships, the Gupta & Dan (2004) and Carter and Hayes (1977) models showed near identical REML linear regression fit parameters. All relationships other than the Morgan et al. (2003) pooled relationship, greatly underestimated the µ-FEM apparent strain energy density (SED. app. ) when considering a homogeneous tissue modulus in the µ-FEMs. The same result with the pooled relationship did not hold true when heterogeneous tissue modulus was considered in the µ-FEMs. The Büchler et al., (2002) relationship most accurately predicted the SED. app. for this comparison. Interestingly, the Gupta & Dan (2004) and Carter and Hayes (1977) relationships again showed near identical REML linear regression fit parameters. DISCUSSION. This study compared six common density-modulus relationships used to map mechanical properties of bone in shoulder FE studies. It was found that when considering a homogeneous tissue modulus for µ-FEMs, relationships pooled from alternative anatomic locations may accurately predict the mechanical properties of glenoid trabecular bone. However, when considering a heterogeneous tissue modulus, this did not hold true. Further studies to determine if these relationships can be translated to whole bones may provide insight into the predictive capabilities of using pooled density-modulus equations in the mapping of mechanical properties in future FEMs of the shoulder