The significance of physical activity (PA) assessment is widely acknowledged as it can aid in the understanding of pathologies. PA of knee osteoarthritis (KOA) patients has been assessed with varying methods, as it is a disease that is known to impair physical function and activity during daily life. Differences between methods have been described for general outcomes (sport participation or sedentary time), yet failed to describe common activities such as stair locomotion or sit-to-stand (STS) transfers. This study therefore aimed to determine the comparability of various methods to assess daily-life activities in KOA patients.

Sixty-one clinically diagnosed KOA patients wore a tri-axial accelerometer (AX3, Axivity, UK) for one week during waking hours. Furthermore, they performed three physical function tests: a 40-m fast-paced walk test (WT), a timed up-and-go test (TUGT) and a 15 stair-climb test (SCT). Patients were also asked to fill out the Knee Osteoarthritis Outcome Score (KOOS), a KOA-specific questionnaire.

Patients were slightly overweight (average BMI: 27.3±4.8 kg/m2), 60 (±10) years old and predominantly female (53%). The amount of daily level walking bouts was only weakly correlated with the WT performance, representing patients” walking capacity, (ρ=−0.33, p=0.01). Similarly, level-walking bouts during daily life correlated weakly with self-perceived walking capacity addressed by the KOOS (ρ=−0.36, p=0.01). For stair locomotion, a slightly different trend was seen. A moderate correlation was found (ρ=0.65, p<0.001), between the amount of ascending bouts and the objective functional test performance (SCT). However, the subjective assessment of stair ascending limitations (via the KOOS) correlated only weakly with both the functional test performance and the measured level of activity (ρ=−0.30 and −0.35, resp.). Comparable results were found for descending motions. STS transfers during daily life correlated moderately at best with the time to complete the TUGT (ρ=−0.43, p<0.01) and only weakly with the self-perceived effort of STS transfers (ρ=−0.26, p=0.04).

Only weak correlations existed between subjective measures and objective parameters (for both functional tests and daily living activities), indicating that they assess different domains (e.g. self-perceived function vs. actual physical function). Furthermore, when comparing the two objective measures, correlation coefficients increased compared to the subjective methods, yet did not reach strong agreement. These findings suggest that addressing common activities of daily life either subjectively or objectively will result in different patient-related outcomes of a study. Assessment methods should therefore be chosen with caution and compared carefully with other studies.

Introduction. Patients with external fixators are at risk of pin site infection. A more objective assessment of possible pin site infection is warranted, particularly for future home-based monitoring of pin sites. The aim was to determine if thermography can detect signs of inflammation around pin sites by 1) Establishing a maximum temperature cut-off value 2) Investigating the correlation between local temperature and visual signs of inflammation 3) Adjust for anatomical location and ambient room temperature. Method. This was a cross-sectional international multi-center study following STROBE guidelines. All patients with external ring-fixators scheduled for a visit in the out-patient clinic were eligible. Visual signs of inflammation were categorized using the Modified Gordon classification System (MGS, simplified sMGS). Thermographic imaging was done with an infrared camera (FLIR T540) and the maximum temperature within the ROI (MaxTp) was the primary outcome measure. Sample size and reliability were estimated. Cohen-Kappa, ROC-curve/AUC and Poisson regression were used for statistical analysis. Result. Data from 1970 pin sites were included. Inter-rater reliability of MGS was Kappa=0.79 and for MaxTp ICC=0.99 (95%CI: 0.99;0.99). Overall, a tendency of rising temperature with increasing sMGS was seen. The difference between sMGS=0 and sMGS>0 was significant. The performance of MaxTp as a screening tool to detect inflammation was reasonable with an AUC of 0.71 (95% CI: 0.65-0.76). The empirically optimal cut-off value was 34.1°C (Sensitivity=65%, Specificity=72%, Positive predictive value=23%, Negative Predictive value=94%). A 1°C increase in MaxTp increased the RR of visual signs of inflammation by a factor 1.5 (95% CI: 1.3; 1.7). Conclusion. We found a clinical positive association between the temperature at the pin site measured with thermography and visual signs of inflammation. The empirically optimal temperature cut-off value for inflammation screening was 34.1°C. Thermography may be a promising tool for a for a future point of care technology

Introduction. The objective assessment of shoulder function is important for personalized diagnosis, therapies and evidence-based practice but has been limited by specialized equipment and dedicated movement laboratories. Advances in AI-driven computer vision (CV) using consumer RGB cameras (red-blue-green) and open-source CV models offer the potential for routine clinical use. However, key concepts, evidence, and research gaps have not yet been synthesized to drive clinical translation. This scoping review aims to map related literature. Method. Following the JBI Manual for Evidence Synthesis, a scoping review was conducted on PubMed and Scholar using search terms including “shoulder,” “pose estimation,” “camera”, and others. From 146 initial results, 27 papers focusing on clinical applicability and using consumer cameras were included. Analysis employed a Grounded Theory approach guided iterative refinement. Result. Studies primarily used Microsoft Kinect (infrared-based depth sensing, RGB camera; discontinued) or monocular consumer cameras with open-source CV-models, sometimes supplemented by LiDAR (laser-based depth sensing), wearables or markers. Technical validation studies against gold standards were scarce and too inconsistent for comparison. Larger range of motion (RoM) movements were accurately recorded, but smaller movements, rotations and scapula tracking remained challenging. For instance, one larger validation study comparing shoulder angles during arm raises to a marker-based gold-standard reported Pearson's R = 0.98 and a standard error of 2.4deg. OpenPose and Mediapipe were the most used CV-models. Recent efforts try to improve model performance by training with shoulder specific movements. Conclusion. Low-cost, routine clinical movement analysis to assess shoulder function using consumer cameras and CV seems feasible. It can provide acceptable accuracy for certain movement tasks and larger RoM. Capturing small, hidden or the entirety of shoulder movement requires improvements such as via training models with shoulder specific data or using dual cameras. Technical validation studies require methodological standardization, and clinical validation against established constructs is needed for translation into practice

Summary. Objective assessment of tendon histomorphology, particularly in the context of tissue repair, requires comprehensive analyses of both cellular distribution and matrix architecture. Fourier Transform analyses of histological images collected with second harmonic generation (SHG-FT) technique provide objective, quantitative assessment of collagen fiber organization with high specificity. Concurrent nuclear staining allows simultaneous analyses of cell morphology and distribution. Introduction. Tendon injuries can be career-limiting in human and equine athletes, since the architectural organization of the tissues are lost in the course of fibrotic repair. Objective assessment of tendon repair is problematical, particularly in research addressing potential therapies. Fourier Transform analyses of histological images collected with second harmonic generation (SHG-FT) technique can provide objective, quantitative assessments of collagen fiber organization with high specificity. This study describes the use of SHG-FT with fluorescently-labelled tendon-derived cells (TDC) in an in-vivo model of equine tendinitis to assess the temporal and spatial effects of cell delivery on collagen fiber organization. Materials and methods. Collagenase-induced tendinitis was created in the mid-metatarsal region of one hindlimb superficial digital flexor tendons (SDFT) in two horses. SDFTs from two clinically normal adult horses and were also used as controls. Autogenous TDCs were isolated from the lateral digital extensor tendon of the contralateral hind limb. Four weeks post-collagenase injection, 10×10. 6. DiI-labeled TDCs were injected into the tendon lesions. Tendon samples were obtained for histologic evaluation following euthanasia, 2-weeks after cell injections. Tendon samples were cryo-sectioned to 25–30μ exposed to nuclear counter stains (DAPI and PI) and imaged immediately through a confocal microscope (Zeiss LSM 710) with a 2-photon laser source, to obtain backward SHG (bSHG) and forward SHG (fSHG) images. In addition, images with DiI and DAPI fluorescence were acquired using 500–550 nm (green) or 565–615 nm (orange) emission filters, respectively. Fourier analysis of the SHG images was carried out using imageJ software. Results. DiI-labeled TDCs could be imaged successfully under two-photon fluorescence concurrently with SHG imaging. This was possible because the excitation wavelength of the two-photon laser (780nm) and detection of emissions above 565nm do not interfere with the bSHG band (380–400nm). Images collected with bSHG included signals from DAPI-stained nuclei. In contrast, emissions from PI-labeled nuclei were acquired independently of SHG signals. The contrast generated by individual collagen fibers was higher in images collected with fSHG than bSHG. SHG-FT of fSHG images provided accurate assessment of collagen fiber orientation in repair tissue and normal tendon. Discussion/Conclusions. Objective assessment of collagen orientation, along with spatial distribution of cells within healing tendon serves as useful indices of healing. Injected DiI-labeled TDCs could be imaged successfully under two-photon fluorescence concurrently with SHG imaging. However, DiI fluorescence is susceptible to photo-bleaching during SHG acquisition. Use of an alternative nuclear counter stains, such as PI, that do not emit along with SHG signal should be considered to optimise data acquisition and support simultaneous analyses of collagen structure, cellular morphology and cell distribution. SHG-FT histologic analysis along with biochemical and biomechanical indices collectively provide comprehensive assessment of therapies for tendon repair

Background. Shoulder pain limits range of motion (ROM) and reduces performing activities of daily living (ADL). Objective assessment of shoulder function could be of interest for diagnosing shoulder pathology or functional assessment of the shoulder after therapy. The feasibility of 2 wearable inertial sensors for functional assessment to differentiate between healthy subjects and patients with unilateral shoulder pathology is investigated using parameters as asymmetry. Methods. 75 subjects were recruited into this study and were measured for at least 8 h a day with the human activity monitor (HAM) sensor. In addition, patients completed the Disability of the Arm, Should and Hand (DASH) score and the Simple Shoulder Test (SST) score. From 39 patients with a variety of shoulder pathologies 24 (Age: 53.3 ± 10.5;% male: 62.5%) complete datasets were successfully collected. From the 36 age-matched healthy controls 28 (Age: 54.9 ± 5.8;% male = 57.1%) full datasets could be retrieved. Activity parameters were obtained using a self-developed algorithm (Matlab). Outcome parameters were gyroscope and accelerometry-based relative and absolute asymmetry scores (affected/unaffected; dominant/non-dominant) of movement intensity. Results & Discussion. The absolute and relative asymmetry scores of the accelerometry-based intensity results for a threshold of > 0.1 g (AUC 0.821 and AUC 0.827) proved to be slightly more distinctive to the gyroscope-based intensity results for a threshold of > 10 deg/s (AUC 0.807 and 0.795) to distinguish between the healthy group and the shoulder group. Asymmetry (< 1%) was nearly absent in healthy controls (5/56 subjects) using the accelerometry-based intensity (> 0.1g) results but common in patients (29/48 subjects). A moderate, significant correlation was found between the asymmetry scores and the DASH score, thus complementary use is advised. The asymmetry scores had no correlation to the SST score. Conclusion. Ambulant assessment of shoulder activity using human activity monitors, containing a gyroscope and accelerometer, during ADL is feasible. The accelerometry-based and gyroscope-based absolute and relative asymmetry scores are promising parameters to diagnose or assess function of the shoulder. A moderate correlation was found between the DASH score and the activity monitor parameters, suggesting both could be used complementary to assess function

Background. Training within surgery is changing from the traditional Halstedian apprenticeship model. There is need for objective assessment of trainees, especially their technical skills, to ensure they are safe to practice and to highlight areas for development. In addition, due to working time restrictions in both the UK and the US, theatre time is being limited for trainees, reducing their opportunities to learn such technical skills. Simulation is one adjunct to training that can be utilised to both assess trainees objectively, and provide a platform for trainees to develop their skills in a safe and controlled environment. The insertion of a dynamic hip screw (DHS) relies on complex psychomotor skills to obtain an optimal implant position. The tip-apex distance (TAD) is a measurement of this positioning, used to predict failure of the implant. These skills can be obtained away from theatre using workshop bone simulation, however this method does not utilise fluoroscopy due to the associated radiation risks. FluoroSim is a novel digital fluoroscopy simulator that can recreate digital radiographs with workshop bone simulation for the insertion of a DHS guide-wire. In this study, we present the training effect demonstrated on FluoroSim. The null hypothesis states that no difference will be present between users with different amounts of exposure to FluoroSim. Methods. Medical students were recruited from three London universities and randomised into a training (n=23) and a control (n=22) cohort. All participants watched a video explanation of the simulator and task and were blinded to their allocation. Training participants completed 10 attempts in total, 5 attempts in week one, followed by a one week wash out period, followed by 5 attempts in week 2. The control group completed a single attempt each week. For each attempt, 5 metrics were recorded; TAD, procedural time, number of radiographs, number of guide-wire retires and cut-out rate (COR). Results. No significant difference was present for any metric between the groups at baseline; randomisation had produced heterogeneous groups minimising selection bias. Intragroup training effect (comparison of initial and last attempt) was significant for all metrics in the training group (p < 0.05) but for no metrics in the control group. The intergroup training effect (comparison of training group attempt ten to control group attempt ten) was present for procedural time, number of radiographs and number of guide-wire retries (p < 0.05). Significance was not reached for TAD and COR. Conclusion. FluoroSim shows skill acquisition with repeat exposure, so the null hypothesis can be rejected. This study has demonstrated the merits of FluoroSim as a training adjunct for psychomotor skill development in a DHS setting

Orthopaedic training sessions, vital for surgeons to understand post-operative joint function, are primarily based on passive and subjective joint assessment. However, cadaveric knee simulators, commonly used in orthopaedic research,. 1. could potentially benefit surgical training by providing quantitative joint assessment for active functional motions. The integration of cadaveric simulators in orthopaedic training was explored with recipients of the European Knee Society Arthroplasty Travelling Fellowship visiting our institution in 2018 and 2019. The aim of the study was to introduce the fellows to the knee joint simulator to quantify the surgeon-specific impact of total knee arthroplasty (TKA) on the dynamic joint behaviour, thereby identifying potential correlations between surgical competence and post-operative biomechanical parameters. Eight fellows were assigned a fresh-frozen lower limb each to plan and perform posterior-stabilised TKA using MRI-based patient-specific instrumentation. Surgical competence was adjudged using the Objective Structured Assessment of Technical Skills (OSATS) adapted for TKA. 2. All fellows participated in the in vitro specimen testing on a validated knee simulator,. 3. which included motor tasks – passive flexion (0°-120°) and active squatting (35°-100°) – and varus-valgus laxity tests, in both the native and post-operative conditions. Tibiofemoral kinematics were recorded with an optical motion capture system and compared between native and post-operative conditions using a linear mixed model (p<0.05). The Pearson correlation test was used to assess the relationship between the OSATS scores for each surgeon and post-operative joint kinematics of the corresponding specimen (p<0.05). OSATS scores ranged from 79.6% to 100% (mean=93.1, SD=7.7). A negative correlation was observed between surgical competence and change in post-operative tibial kinematics over the entire range of motion during passive flexion – OSATS score vs. change in tibial abduction (r=−0.87; p=0.003), OSATS score vs. change in tibial rotation (r=−0.76; p=0.02). When compared to the native condition, post-operative tibial internal rotation was higher during passive flexion (p<0.05), but lower during squatting (p<0.033). Post-operative joint stiffness was greater in extension than in flexion, without any correlation with surgical competence. Although trained at different institutions, all fellows followed certain standard intraoperative guidelines during TKA, such as achieving neutral tibial abduction and avoiding internal tibial rotation,. 4. albeit at a static knee flexion angle. However, post-operative joint kinematics for dynamic motions revealed a strong correlation with surgical competence, i.e. kinematic variability over the range of passive flexion post-TKA was lower for more skilful surgeons. Moreover, actively loaded motions exhibited stark differences in post-operative kinematics as compared to those observed in passive motions. In vitro testing on the knee simulator also introduced the fellows to new quantitative parameters for post-operative joint assessment. In conclusion, the inclusion of cadaveric simulators replicating functional joint motions could help quantify training paradigms, thereby enhancing traditional orthopaedic training, as was also the unanimous opinion of all participating fellows in their positive feedback

Introduction. Limited physical activity (PA) is one indication for orthopaedic intervention and restoration of PA a treatment goal. However, the objective assessment of PA is not routinely performed and in particular the effect of spinal pathology on PA is hardly known. It is the purpose of this study using wearable accelerometers to measure if, by how much and in what manner spinal stenosis affects PA compared to age-matched healthy controls. Patients & Methods. Nine patients (m/f= 5/4, avg. age: 67.4 ±7.7 years, avg. BMI: 29.2 ±3.5) diagnosed with spinal stenosis but without decompressive surgery or other musculoskeletal complaints were measured. These patients were compared to 28 age-matched healthy controls (m/f= 17/11, avg. age: 67.4 ±7.6 years, avg. BMI: 25.3±2.9). PA was measured using a wearable accelerometer (GCDC X8M-3) worn during waking hours on the lateral side of the right leg for 4 consecutive days. Data was analyzed using previously validated activity classification algorithms in MATLAB to identify the type, duration and event counts of postures or PA like standing, sitting, walking or cycling. In addition, VAS pain and OSWESTRY scores were taken. Groups were compared using the t-test or Mann-Whitney U-test where applicable. Correlations between PA and clinical scores were tested using Pearson”s r. Results. Spinal stenosis patients showed much lower PA than healthy controls regarding all parameters like e.g. daily step count (2946 vs 8039, −63%, p<0.01) or the relative daily time-on-feet (%) (8.6% vs 28.3%, −70%, p<0.01) which is matched with increased sitting durations (80.3% vs 58.8%, p<0.01). Also qualitative parameters such as walking cadence was reduced in stenosis patients (83.7 vs 97.8 steps/min). With stenosis no patient ever walked >1000 steps without interruption. Also the number of walking bouts between 250–1000 steps was 4.5 times lower than in healthy controls (p<0.01). When the relative distribution of walking bout length was calculated, it became visible that stenosis patients showed more short walking bouts of 10–50 steps (p<0.05). There were no strong and significant correlations between the clinical scores and PA parameters. Discussion & Conclusions. Spinal stenosis greatly reduced physical activity to levels below WHO guidelines (e.g. <5000 steps= sedentary lifestyle) where the risk for general health (overall mortality), cardiovascular or endocrinological health is significantly increased. Activity levels are lower than reported for end-stage hip or knee osteoarthritis. Therefore, spinal stenosis patients should not only receive pain medication, but be made aware of their limited PA and its detrimental health effects, participate in activation programs, or be considered for surgical intervention. The absence of long walking bouts and the relatively more frequent short walking bouts seem indicative of intermittent claudication as typical in spinal stenosis

Background. To complement subjective patient-reported outcome measures, objective assessments are needed. Activity is an objective clinical outcome which can be measured with wearable activity monitors (AM). AM's have been validated and used in joint arthroplasty patients to count postures, walking or transfers. However, for demanding patients such as after sports injury, running is an important activity to quantify. A new AM algorithm to distinguish walking from running is trialed in this validation study. Methods. Test subjects (n=9) performed walking and running bouts of 30s duration on a treadmill at fixed speeds (walking: 3, 4, 5, 7km/h, running: 5, 7, 9, 12, 15km/h) and individually preferred speeds (slow, normal, fast, maximum, walk/run transition). Flat and inclined surfaces (8%, 16%), different footwear (soft, hard, barefoot) and running styles (hind/fore-foot) were tested. An AM (3D accelerometer) was worn on the lateral thigh. Previously validated algorithms to classify all gait as walking were adapted to differentiate running from walking, the main criterium being vertical acceleration peaks exceeding 2g within each subsequent 2s-interval. Independently annotated video observation served as reference. Results. A total of 312 events had to be classified. Walking bouts (162) were correctly identified in 158 cases resulting in 97.5% detection accuracy. Running bouts (150) were correctly identified in 146 cases (97.3%). In 8 walking bouts (5.0%), an additional running event was falsely detected. These happened at 7km/h and maximum (>8.6km/h) walking speed and during continuous walk/run transitions at individual transition speeds. In 12 running bouts (8.2%), an additional walking event was falsely detected. These happened during slow running (<7km/h). Timing event duration and step counts were >95% accurate. Conclusions. Thigh-worn AM and a simple algorithm can distinguish walking from running at high accuracy and thus can serve doctors, therapists or coaches to objectify outcomes, decisions about effective and safe exercise intensities or return-to-play

Background. Assessment of functional outcome after total hip arthroplasty (THA) often involves subjective patient-reported outcome measures (PROMs) whereas analysis of gait allows more objective assessment. The aims of the study were to compare longitudinal changes of WOMAC function score and ambulatory gait analysis after THA, between patients with low and high self-reported levels of physical function. Methods. Patients undergoing primary THA (n=36; m/f=18/18; mean age=63.9; SD=9.8yrs; BMI=26.3 SD=3.5) were divided in a high and low function group, on their preoperative WOMAC function score. Patients were prospectively measured preoperatively and 3 and 12 months postoperatively. WOMAC function scores 0–100) were compared to inertial sensor based ambulatory gait analysis. Results. WOMAC function scores significantly improved in both low and high groups at 3 months postoperatively whereas gait parameters only improved in with a low pre-operative function. Between 3 and 12 months postoperatively, function scores had not significantly further improved whereas several gait parameters significantly improved in the low function group. WOMAC function scores parameters were only moderately correlated (Spearman's r = 0.33–0.51). Discussion. In routine longitudinal assessment of physical function following THA, ambulatory gait analysis can be supplementary to WOMAC. As gait significantly improved during the first 3 months and following 9 months after THA in patients with a low preoperative level of physical function only, assessment of more demanding tasks than gait may be more sensitive to capture functional improvement in patients with high preoperative function. Acknowledgements. This article presents independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research programme (RP-PG-0407-10070). The views expressed in this article are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. The research team acknowledges the support of the NIHR, through the Comprehensive Clinical Research Network

Besides eliminating pain, restoring activity is a major goal in orthopaedic interventions including joint replacement or trauma surgery following falls in frail elderly, both treatments of highest socio-economic impact. In joint replacement and even more so in frail elderly at risk of falling, turns are assessed in clinical tests such as the TUG (Timed Get-up-and-Go), Tinetti, or SPPB so that classifying turning movements in the free field with wearable activity monitors promises clinically valuable objective diagnostic or outcome parameters. It is the aim of this study to validate a computationally simple turn detection algorithm for a leg-worn activity monitor comprising 3D gyroscopes. A previously developed and validated activity classification algorithm for thigh-worn accelerometers was extended by adding a turn detection algorithm to its decision tree structure and using the 3D gyroscope of a new 9-axis IMU (56×40×15mm, 25g, f=50Hz,). Based on published principles (El-Gohary et al. Sensors 2014), the turn detection algorithm filters the x-axis (thigh) for noise and walking (Butterworth low-pass, 2. nd. order with a cut-off at 4Hz and 4. th. order with a cut-off at 0.3Hz) before using a rotational speed threshold of 15deg/s to identify a turn and taking the bi-lateral zero-crossings as start and stop markers to integrate the turning angle. For validation, a test subject wore an activity monitor on both thighs and performed a total of 57 turns of various types (walking, on-the-spot, fast/slow), ranges (45 to 360deg) and directions (left/right) in free order while being video-taped. An independent observer annotated the video so that the algorithmic counts could be compared to n=114 turns. Video-observation was compared to the algorithmic classification in a confusion matrix and the detection accuracy (true positives) was calculated. In addition, 4-day continuous activity measures from 4 test subjects (2 healthy, 2 frail elderly) were compared. Overall, only 5/114 turns were undetected producing a 96% detection accuracy. No false positives were classified. However, when detection accuracy was calculated for turning angle intervals (45°: 30–67.5°; 90°: 67.5–135°; 180°: 135–270°; 360°: 270–450°), accuracy for all interval classifications combined dropped to 83.3% with equal values for left and right turns. For the 180° and 360°, accuracy was 100% while for the shorter 45° and 90° turns accuracy was 75% and 71% only, mainly because subsequent turns were not separated. Healthy subjects performed between 470 (office worker) and 823 (house wife) turns/day while frail elderly scored 128 (high fall risk) to 487 turns/day (low fall risk). Turns/day and steps/day were not correlated. In healthy subjects ca. 50% of turns were in the 45° category compared to only ca. 35% in frail elderly. Turn detection for a thigh-worn IMU activity monitor using a computationally simple algorithm is feasible with high general detection accuracy. The classification and separation of subsequent short turns can be further improved. In multi-day measurement, turns/day and the distribution of short and long turns seem to be a largely independent activity parameter compared to step counts and may improve objective assessment of fall risk or arthroplasty outcome

INTRODUCTION. This study investigates the relationship between direct measurement of outcome and patient report of that outcome via the OKS. The stability of this relationship over time following surgery is also assessed. METHODS. 183 TKA patients were assessed pre-operatively and at 6, 26 and 52 weeks post-op. Oxford Knee Score was obtained along with measures of pain intensity, knee flexion, lower limb power and timed functional assessment. Correlation of performance variables with the OKS was assessed, and regression analysis performed on those that formed significant associations. Significance was accepted at p = 0.05. RESULTS. Pain intensity and functional ability improved with time post-op. Functional scores correlated modestly with OKS, consistently over the assessment period. Pain correlated poorly pre-op but well post-op. Regression modelling was able to explain differing amounts of the variation in OKS at the 4 time points; 34.8% pre-operatively, 44.0% at 6 weeks, 56.9% at 26 weeks and 62.3% at 52 weeks post-op. Pain was the dominant factor in deriving all of these models. DISCUSSION. Substantial variation was found in objective assessment of function and patient report of that function through the OKS. This relationship changed with time post-operatively. The explanatory power of the models improved as pain intensity reduced. CONCLUSION. These results question the accuracy of PROMS in representing the observed ability to perform functional tasks, which has implications for assessing outcome

Background. Technical skill is an essential domain of surgical competency. Arthroscopic surgery forms a particularly challenging subset of these skills. The innate ability to acquire these skills is not fully understood. The aim of this study was to investigate the innate arthroscopic skills and learning curve patterns of medical students - our future surgeons. Methods. Two arthroscopic tasks (one shoulder and one knee) were set up in a bioskills laboratory to represent core skills required for arthroscopic training. Twenty medical students with no previous arthroscopic surgery experience were recruited and their performance assessed whilst undertaking each task on 30 occasions. The primary outcome variable was success or failure. Individuals were assessed as ‘competent’ if they stabilised their learning curve within 20 episodes. The secondary outcome measure was an objective assessment of technical dexterity using a validated Motion Analysis system (time taken to complete tasks, total path length of the subject's hands, and number of hand movements). Results. There was variability in the performance of the students. Seven students in the shoulder task and four students in the knee task were unable to achieve competence. Motion analysis data demonstrated that students who achieved task competence had better objective technical dexterity and therefore better innate arthroscopic ability. For the shoulder task, these differences were statistically significant for ‘path length’ and ‘hand movement’ (p<0.05, Mann-Whitney U test). For the knee task, the differences were statistically significant for ‘path length’ (P<0.05, Mann-Whitney U test). Conclusion. Variation in innate arthroscopic skill exists in our future surgeons with some individuals being unable to achieve competence at basic arthroscopic tasks despite sustained practice. It may be of great value to identify individuals who lack innate arthroscopic skills early in their career in order to provide them with focused training and relevant career guidance

Background. The ability to learn arthroscopic surgery is an important aspect of modern day orthopaedic surgery. Knowing that variation in innate ability exists amongst medical students, the aim of this study was to investigate the effect of training on the arthroscopic surgical performance of our future orthopaedic surgeons (medical students). Methods. Two arthroscopic tasks (one shoulder and one knee) were set up in a bioskills laboratory to represent core skills required for arthroscopic training. Thirty three medical students with no previous arthroscopic surgery experience were randomised to a ‘Trained’ (n=16) and ‘Non-trained’ (n=17) cohort. Both groups watched an instructional video. The Trained cohort also received specific training on the tasks prior to their first episode. Thirty episodes of each task were then undertaken. The primary outcome variable was success or failure. Individuals were assessed as ‘competent’ if they stabilised their learning curve within 20 episodes. The secondary outcome measure was an objective assessment of technical dexterity using a validated Motion Analysis system (time taken to complete tasks, total path length of the subject's hands, and number of hand movements). Results. During the shoulder task, one subject in the Trained cohort failed to achieve competence compared with six subjects in the Non-trained cohort. During the knee task, two subjects in each cohort failed to achieve competence. Performance of the subjects in the Trained cohort during the shoulder task was significantly better (p<0.05, Chi-squared test). Based on the objective motion analysis parameters, the Trained cohort performed better than the Non-trained cohort for both tasks. This was statistically significant (p<0.05, Mann-Whitney U test) for the shoulder task. Conclusion. As expected, specific training can improve the arthroscopic performance of novices. There were, however, individuals who could not achieve competency in basic arthroscopic tasks even with focused training. Such assessments might influence students' future career choices

Summary Statement. Conventional imaging techniques lack the ability to objectively assess early stages of intervertebral disc degeneration, characterised by glycosaminoglycan loss. This study shows that MRI T2∗ mapping correlates positively with GAG content and that it provides continuous measurements for disc degeneration. Introduction. Early degenerative changes arise in the nucleus pulposus (NP) and are characterised by a loss of glycosaminoglycans (GAG). Early disc degeneration (DD) could possibly be treated with upcoming regenerative therapies (e.g. with stem cells and/or growth factors). In order to evaluate degeneration and treatments, a sensitive diagnostic tool is needed. While conventional magnetic resonance imaging (MRI) and x-ray techniques can detect late stages of DD, these techniques lack the ability to detect early degenerative changes. Recently, T2∗ mapping has been proposed as a new technique to evaluate early IVD degeneration, yet the correlation with GAG content and histological features has not been previously investigated. The objective of this study was to determine the value of T2∗ mapping in diagnosing DD by correlating this technique with the biochemical composition of IVDs. Materials & Methods. Six caprine lumbar spines obtained from an in vivo study and two healthy goat spines from the local abattoir, encompassing a total of 48 IVDs, were examined using sagittal standard T2-weighted and T2∗ mapping MRI protocols at 1.5 Tesla. Regions of interest (ROIs) were drawn on the T2∗ maps, covering the IVD. Based on T2 weighted MRI, discs were morphologically classified using the Pfirrmann score. Histological and macroscopic features were evaluated based on grading scales adapted for goat DD. Finally, GAG content was determined using colorimetric analysis (DMMB assay). Correlations between variables were analysed using Pearson correlation (r) coefficients (parametric data) or Spearman's rho (ρ) coefficients (non-parametric data). Results. The mean GAG content in the NP was 450 μg/mg dry weight (range 20–730 μg/mg dry weight) and the mean histological grade was 2.2 (range 0–6), corresponding with relatively mild disc degeneration. A linear positive correlation was observed between T2∗ and NP GAG content (r = 0.65, p < 0.001). T2∗ in the NP decreased linearly with increasing degeneration as assessed with macroscopic (ρ = 0.33, p < 0.05) and histological (ρ = −0.45, p < 0.05) grading, as well as with the Pfirrmann scoring system (ρ = −0.67, p < 0.001). Discussion. T2∗ mapping is a relatively new MRI technique which allows for measurements on a continuous scale, is acquired in less time than T2 mapping and minimises observer bias compared to grading systems. Although limited by a small sample size (n=48), this study showed a relatively good, linear correlation between T2∗ and GAG content in the NP, suggesting that T2∗ mapping may be an efficient and reliable tool for the objective assessment of proteoglycan content in early DD. Furthermore, with minor software modifications, it can be implemented on a standard 1.5 Tesla clinical MRI scanner. Future research should aim at optimizing the efficiency and user-friendliness of the T2∗ mapping protocol as well as yielding an even stronger correlation between T2∗ mapping and glycosaminoglycan content in human IVD tissue

The aim of this study was to validate the use of three models of fracture fixation in the assessment of technical skills. We recruited 21 subjects (six experts, seven intermediates, and eight novices) to perform three procedures: application of a dynamic compression plate on a cadaver porcine model, insertion of an unreamed tibial intramedullary nail, and application of a forearm external fixator, both on synthetic bone models. The primary outcome measures were the Objective Structural Assessment of technical skills global rating scale on video recordings of the procedures which were scored by two independent expert observers, and the hand movements of the surgeons which were analysed using the Imperial College Surgical Assessment Device. The video scores were significantly different for the three groups in all three procedures (p < 0.05), with excellent inter-rater reliability (α = 0.88). The novice and intermediate groups specifically were significantly different in their performance with dynamic compression plate and intramedullary nails (p < 0.05). Movement analysis distinguished between the three groups in the dynamic compression plate model, but a ceiling effect was demonstrated in the intramedullary nail and external fixator procedures, where intermediates and experts performed to comparable standards (p > 0.6). A total of 85% (18 of 21) of the subjects found the dynamic compression model and 57% (12 of 21) found all the models acceptable tools of assessment. This study has validated a low-cost, high-fidelity porcine dynamic compression plate model using video rating scores for skills assessment and movement analysis. It has also demonstrated that Synbone models for the application of and intramedullary nail and an external fixator are less sensitive and should be improved for further assessment of surgical skills in trauma. The availability of valid objective tools of assessment of surgical skills allows further studies into improving methods of training

Objectives

Our study aimed to examine not only the incidence but also the impact of noise from two types of total hip replacement articulations: ceramic-on-ceramic and ceramic-on-polyethylene.