Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty, particularly for low volume surgeons. The recent introduction of robotic-arm assisted systems has allowed for increased accuracy, however new systems typically have learning curves. The objective of this study was to determine the learning curve of a robotic-arm assisted system for UKA. Methods A total of 152 consecutive robotic-arm assisted primary medial UKA were performed by five surgeons between 2017 and 2021. Operative times, implant positioning, reoperations and patient-reported outcome measures (PROMS; Oxford Knee Score, EuroQol-5D, and Forgotten Joint Score) were recorded. There was a learning curve of 11 cases with the system that was associated with increased operative time (13 minutes, p<0.01) and improved insert sizing over time (p=0.03). There was no difference in implant survival (98.2%) between learning and proficiency phases (p = 0.15), and no difference in survivorship between ‘high’ and ‘low’ usage surgeons (p = 0.23) at 36 months. There were no differences in PROMS related to the learning curve. This suggested that the learning curve did not lead to early adverse effects in this patient cohort. The introduction of a robotic-arm assisted UKA system led to learning curves for operative time and implant sizing, but there was no effect on patient outcomes at early follow- up. The short learning curve was independent of UKA usage and indicated that robotic-arm assisted UKA may be particularly useful for low-usage surgeons

Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are well-established operative interventions in the treatment of knee osteoarthritis (KOA). However, which of these interventions is more beneficial, to patients with KOA, is not known and remains a topic of much debate. Aims: (i) To determine whether UKA or HTO is more beneficial in the treatment of isolated medial compartment KOA, via an assessment of patient-reported outcome measures (PROMs). (ii) To investigate the relationship between PROMs and radiographic parameters of knee joint orientation/alignment. This longitudinal observational study assessed a total of 42 patients that had undergone UKA (n=23) or HTO (n=19) to treat isolated medial compartment KOA. The PROMs assessed, pre-operatively and 1-year post-operatively, consisted of the: self-administered comorbidity questionnaire; short form-12; oxford knee score; knee injury and osteoarthritis outcome score; and the EQ-5D-5L. The radiographic parameters of knee joint alignment/orientation assessed, pre-operatively and 8-weeks post-operatively, included the: hip-knee-ankle angle; mechanical axis deviation; and the angle of the Mikulicz line. Statistical analysis demonstrated an overall significant (p<0.001), pre-operative to post-operative, improvement in the PROM scores of both groups. There were no significant differences in the post-operative PROM scores of the UKA and HTO group. Correlation analyses revealed that pre-operatively, a more distolaterally angled Mikulicz line was associated with worse knee function (p<0.05) and overall health (p<0.05); a relationship that, until now, has not been investigated nor commented upon within the literature. UKAs and HTOs are both efficacious operations that provide a comparable degree of clinical benefit to patients with isolated medial compartment KOA. To further the scientific/medical community's understanding of the factors that impact upon health-outcomes in KOA, future research should seek to investigate the mechanism underlying the relationship, between Mikulicz line and PROMs, observed within the current study

Abstract. Purpose. Clinical registries are an important aspect of orthopaedic research in assessing the outcomes of surgical intervention and track medical devices. This study aimed to explore the research methodology available to account for patients lost to follow-up (LTFU) specifically in studies related to arthroscopic intervention and whether the rates of patient LTFU are within the acceptable margins for survey studies. Methods. A scoping review, where a literature search for studies from nine arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on nine national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multi-centre registries. Studies were then divided into categories based on method of LTFU analysis used. Results. Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n=10), referencing validation studies (n=12), contacting non-responders (n=4), and sensitivity analyses (n=1). Referencing validation studies was the most common method (n=12). Majority (n=35) of the studies exceeded the recommended maximum rates for LTFU. Conclusions. Most arthroscopy studies have rates of LTFU higher than traditionally acceptable. Therefore, any conclusions drawn from these research papers may not be sufficiently valid or free from non-response bias

Introduction and Objective. Platelet-Rich-plasma (PRP) has been used in combination with stem cells, from different sources, with encouraging results both in vitro and in vivo in osteochondral defects management. Adipose-derived Stem Cells (ADSCs) represents an ideal resource for their ease of isolation, abundance, proliferation and differentiation properties into different cell lineages. Furthermore, Stem Cells in the adipose tissue are more numerous than from other sources. Aim of this study was to evaluate the potential of ADSCs in enhancing the effect of arthroscopic mesenchymal stimulation combined with infiltration of PRP. Materials and Methods. The study includes 82 patients. 41 patients were treated with knee arthroscopy, Steadman microfractures technique and intraoperative PRP infiltration, Group A. In the Group B, 41 patients were treated knee arthroscopy, Steadman microfractures and intraoperative infiltration of PRP and ADSCs (Group B). Group A was used as a control group. Inclusion criteria were: Age between 40 and 65 years, Outerbridge grade III-IV chondral lesions, Kellegren-Lawrence Grade I-II. Patient-reported outcome measures (PROMs) evaluated with KOOS, IKDC, VAS, SF-12 were assessed pre-operatively and at 3 weeks, 6 months, 1-year post-operative. 2 patients of Group A and 3 patients of Group B, with indication of Puddu plate removal after high tibial osteotomy (HTO), underwent an arthroscopic second look, after specific informed consent obtained. On this occasion, a bioptic sample was taken from the repair tissue of the chondral lesion previously treated with Steadman microfractures. Results. PROMs showed statistically significant improvement (p <0.05) with comparable results in both groups. The histological examination of the bioptic samples in Group B showed a repair tissue similar to hyaline cartilage, according to the International Cartilage Repair Society (ICRS) Visual Histological Assessment Scale. In Group A, the repair tissue was fibrocartilaginous. Conclusions. According to the PROMs and the histological results, showing repair tissue after Steadman microfractures qualitatively similar to hyaline cartilage, the combination of ADSCs and PRP could represent an excellent support to the arthroscopic treatment of focal chondral lesions and mild to moderate osteoarthritis

Introduction and Objective. Postoperative management regimes vary following open reduction and internal fixation of unstable ankle fractures. There is an evolving understanding that poorer outcomes could be associated with non-weight bearing protocols and immobilisation. Traditional non-weight bearing cast immobilisation may prevent loss of fixation, and this practice continues in many centres. The aim of this systematic review and meta-analysis is to compare the complication rate and functional outcomes of early weight-bearing (EWB) versus late weight-bearing (LWB) following open reduction and internal fixation of ankle fractures. Materials and Methods. We performed a systematic review with a meta-analysis of controlled trials and comparative cohort studies. MEDLINE (via PubMed), Embase and the Cochrane Library electronic databases were searched inclusive of all date up to the search time. We included all studies that investigated the effect of weight-bearing following adults ankle fracture fixation by any means. All ankle fracture types, including isolated lateral malleolus fractures, isolated medial malleolus fractures, bi-malleolar fractures, tri-malleolar fractures and Syndesmosis injuries, were included. All weight-bearing protocols were considered in this review, i.e. immediate weight-bearing (IMW) within 24 hours of surgery, early weight-bearing (EWB) within three weeks of surgery, non-weight-bearing for 4 to 6 weeks from the surgery date (or late weight-bearing LWB). Studies that investigated mobilisation but not weight-bearing, non-English language publications and tibial Plafond fractures were excluded from this systematic review. We assessed the risk of bias using ROB 2 tools for randomised controlled trials and ROBINS-1 for cohort studies. Data extraction was performed using Covidence online software and meta-analysis by using RevMan 5.3. Results. After full-text review, fourteen studies (871 patients with a mean age ranged from 35 to 57 years) were deemed eligible for this systematic review; ten randomised controlled trials and four comparative cohort studies. Most of the included studies were rated as having some concern with regard to the risk of bias. There is no important difference in the infection rate between protected EWB and LWB groups (696 patients in 12 studies). The risk ratio (RR) is 1.30, [95% CI 0.74 to 2.30], I. 2. = 0%, P = 0.36). Other complications were rare. The Olerud-Molander Ankle Score (OMAS) was the widely used patient-reported outcome measure after ankle fracture fixation among the studies. The result of the six weeks OMAS analysis (three RCTs) was markedly in favour of the early weight-bearing group (MD = 10.08 [95% CI 5.13 to 15.02], I. 2. = 0%P = <0.0001). Conclusions. The risk of postoperative complications is an essential factor when considering EWB. We found that the overall incidence of surgical site infection was 6%. When comparing the two groups, the incidence was 5.2% and 6.8% for the LWB and EWB groups. This difference is not clinically important. On the other hand, significantly better early functional outcome scores were detected in the EWB group. These results are not without limitations. Protected early weight-bearing following open reduction and internal fixation of ankle fractures is potentially safe and improve short-term functional outcome. Further good-quality randomised controlled trials would be needed before we could draw a more precise conclusion

Abstract. Objective. In this phase 2 clinical trial (EudraCT 2011-000541-20) we examined the effect of denosumab versus placebo on osteolytic lesion activity in patients undergoing revision surgery after THA. Methods. Men and women ≥ 30 years old scheduled for revision surgery for symptomatic, radiologically-confirmed osteolysis were randomised (1:1) to receive either denosumab 60mg or placebo subcutaneously eight weeks prior to operation. At surgery, biopsies from the osteolytic membrane-bone interface were taken for histomorphometric analysis of osteoclast number, the primary outcome measure. Secondary outcome measures included other static histomorphometric indices and systemic bone turnover markers. Adverse events and patient-reported clinical outcome scores were recorded as safety endpoints. Results. Of the 24 subjects enrolled, 22 completed the study (10 denosumab) and comprise the per-protocol analysis. There were no differences in baseline characteristics and bone turnover markers between groups (p>0.05). The denosumab group had 78% fewer osteoclasts at osteolytic lesion sites (95% CI −61 to −95, P=0.011), 81% lower osteoclast surface (−70 to −95, P=0.009), and 73% lower eroded surface (−54 to −92, P=0.020) compared to the placebo group. Number of osteoblasts and osteoblast surface were also reduced by 81% (−62 to −100, p=0.021) and 82% (−64 to −101, p=0.017), respectively. Immunocytochemistry for cell proliferation (Ki67) and apoptosis (Caspase 3) identified no differences between the groups (p>0.05). At surgery, serum CTX-I in the denosumab group was 80% lower (−65 to −95, p<0.001), TRAP5b −65% (−40 to −90, p<0.001), PINP −53% (−41 to −65, p<0.001). Patient-reported outcome measures and the rate of adverse events (denosumab 6, placebo 7) were similar between groups (P>0.05). Conclusion. A single dose of denosumab reduced osteoclast activity within osteolytic lesions and was safe to administer. These data provide a biological basis for a phase 3 trial using clinical outcomes of pain, function and prosthesis survival as the study endpoints. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Objectives. The patient-rated wrist evaluation (PRWE) and the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire are patient-reported outcome measures (PROMs) used for clinical and research purposes. Methodological high-quality clinimetric studies that determine the measurement properties of these PROMs when used in patients with a distal radial fracture are lacking. This study aimed to validate the PRWE and DASH in Dutch patients with a displaced distal radial fracture (DRF). Methods. The intraclass correlation coefficient (ICC) was used for test-retest reliability, between PROMs completed twice with a two-week interval at six to eight months after DRF. Internal consistency was determined using Cronbach’s α for the dimensions found in the factor analysis. The measurement error was expressed by the smallest detectable change (SDC). A semi-structured interview was conducted between eight and 12 weeks after DRF to assess the content validity. Results. A total of 119 patients (mean age 58 years (. sd. 15)), 74% female, completed PROMs at a mean time of six months (. sd. 1) post-fracture. One overall meaningful dimension was found for the PRWE and the DASH. Internal consistency was excellent for both PROMs (Cronbach’s α 0.96 (PRWE) and 0.97 (DASH)). Test-retest reliability was good for the PRWE (ICC 0.87) and excellent for the DASH (ICC 0.91). The SDC was 20 for the PRWE and 14 for the DASH. No floor or ceiling effects were found. The content validity was good for both questionnaires. Conclusion. The PRWE and DASH are valid and reliable PROMs in assessing function and disability in Dutch patients with a displaced DRF. However, due to the high SDC, the PRWE and DASH are less useful for individual patients with a distal radial fracture in clinical practice. Cite this article: Y. V. Kleinlugtenbelt, R. G. Krol, M. Bhandari, J. C. Goslings, R. W. Poolman, V. A. B. Scholtes. Are the patient-rated wrist evaluation (PRWE) and the disabilities of the arm, shoulder and hand (DASH) questionnaire used in distal radial fractures truly valid and reliable? Bone Joint Res 2018;7:36–45. DOI: 10.1302/2046-3758.71.BJR-2017-0081.R1

Patient-reported outcome measures are a cornerstone of outcome assessment in orthopaedics. However, completing the pencil and paper questionnaires in clinic is something of a burden to the individual patient and the health care institution. We do not provide much in the way of incentives to collect PRO data. Lengthy questionnaires and hidden data analysis offer no direct benefit to the individual patient nor the clinician. Employing ePRO, utilising tablet PCs for questionnaire completion, can improve this situation considerably. Swift and cost-effective data management and instant availability of results using intuitive graphical display make questionnaire completion more rewarding. Direct feedback of PRO data during the consultation can inform the individual's care. Completing electronic questionnaires also makes computer-adaptive testing (CAT) possible. CAT creates dynamic questionnaires, adapting to the individual symptom burden of the individual patient. CAT both increases measurement precision and reduces the number of questions required. As such, ePRO assessment may help to maximise the efficiency and the utilisation of PRO data

The aim of this study was to report the procedure survival and patient-reported outcomes in a consecutive series of patients <50yrs at the time of hip arthroplasty with a metal-on-metal hip resurfacing system who have progressed to a minimum of 10yrs follow-up. Patients presenting for treatment of degenerative conditions of the hip electing to undergo hip resurfacing were included in a clinical registry (N=226 patients; 238 procedures). Procedure survival was confirmed by crosschecking to the Australian Orthopaedic Association National Joint Replacement Registry and comparing to all procedures by other surgeons nationwide. Kaplan-meier survival curves with 95% confidence intervals were constructed, while patient-reported outcome measures were compared with t-tests and postoperative scores assessed with anchor analysis to age and gender-matched normative data. At mean follow up of 12 years, six cases were revised with a cumulative survival rate of 96.8% (95%CI 94.2–99.4) at 15 years. Majority of revisions were early (<3yrs) and occurred in females (N=4). Patient-reported general health, disease state, hip function and activity level maintained large improvements beyond 10 years post-implantation and were equal to or exceeded age and gender-matched normative data. Metal-on-metal hip resurfacing in males and females aged <50 years at time of surgery demonstrated a high rate of cumulative survival beyond 10 years follow up. The results demonstrate excellent outcomes in this age group

Over the past two decades much has been written regarding pain and disability following whiplash injury. Several authors have reported on the relationship between insurance claims and whiplash-associated disorders. Our own experience of over 10-years suggests that fracture may be protective of whiplash injury following road traffic accident (RTA). We exported all ‘medical legal’ cases due to RTA from our EMR system and combined this with patient-reported outcome measures. 1,482 (57%) of all medicolegal cases are due to RTA: 26% ‘head-on’, 34% ‘side-impact’ and 40% ‘rear-ended’. Over half of the vehicles involved are subsequently written-off. While the mean BMI is 27.1, ¼ of this cohort has a BMI over 30 (obese). 163 (11%) patients report a fracture occurring as a result of RTA. Type of impact is significant for fracture (p < 0.05). 47% of RTA which result in fracture are due to ‘head-on’ collision; conversely only 21% are due to ‘rear-ended’ impacts. In 1,324 (89%) of RTA without fracture, patients are twice as likely to report whiplash injury as one of their top-3 sources of pain (p < 0.01). Gender is statistically significant for age (M 44.4, F 38.6, p < 0.05). While the BMI of this cohort is alarming, it is consistent with Irish obesity statistics. Type of impact, in particular ‘head-on’ collision (high kinetic energy event), is significant for fracture. Finally, we report that fracture is significantly protective (p < 0.01) of whiplash injury following RTA

Objectives. This study reports on a secondary exploratory analysis of the early clinical outcomes of a randomised clinical trial comparing robotic arm-assisted unicompartmental knee arthroplasty (UKA) for medial compartment osteoarthritis of the knee with manual UKA performed using traditional surgical jigs. This follows reporting of the primary outcomes of implant accuracy and gait analysis that showed significant advantages in the robotic arm-assisted group. Methods. A total of 139 patients were recruited from a single centre. Patients were randomised to receive either a manual UKA implanted with the aid of traditional surgical jigs, or a UKA implanted with the aid of a tactile guided robotic arm-assisted system. Outcome measures included the American Knee Society Score (AKSS), Oxford Knee Score (OKS), Forgotten Joint Score, Hospital Anxiety Depression Scale, University of California at Los Angeles (UCLA) activity scale, Short Form-12, Pain Catastrophising Scale, somatic disease (Primary Care Evaluation of Mental Disorders Score), Pain visual analogue scale, analgesic use, patient satisfaction, complications relating to surgery, 90-day pain diaries and the requirement for revision surgery. Results. From the first post-operative day through to week 8 post-operatively, the median pain scores for the robotic arm-assisted group were 55.4% lower than those observed in the manual surgery group (p = 0.040). At three months post-operatively, the robotic arm-assisted group had better AKSS (robotic median 164, interquartile range (IQR) 131 to 178, manual median 143, IQR 132 to 166), although no difference was noted with the OKS. At one year post-operatively, the observed differences with the AKSS had narrowed from a median of 21 points to a median of seven points (p = 0.106) (robotic median 171, IQR 153 to 179; manual median 164, IQR 144 to 182). No difference was observed with the OKS, and almost half of each group reached the ceiling limit of the score (OKS > 43). A greater proportion of patients receiving robotic arm-assisted surgery improved their UCLA activity score. Binary logistic regression modelling for dichotomised outcome scores predicted the key factors associated with achieving excellent outcome on the AKSS: a pre-operative activity level > 5 on the UCLA activity score and use of robotic-arm surgery. For the same regression modelling, factors associated with a poor outcome were manual surgery and pre-operative depression. Conclusion. Robotic arm-assisted surgery results in improved early pain scores and early function scores in some patient-reported outcomes measures, but no difference was observed at one year post-operatively. Although improved results favoured the robotic arm-assisted group in active patients (i.e. UCLA ⩾ 5), these do not withstand adjustment for multiple comparisons. Cite this article: M. J. G. Blyth, I. Anthony, P. Rowe, M. S. Banger, A. MacLean, B. Jones. Robotic arm-assisted versus conventional unicompartmental knee arthroplasty: Exploratory secondary analysis of a randomised controlled trial. Bone Joint Res 2017;6:631–639. DOI: 10.1302/2046-3758.611.BJR-2017-0060.R1

Background. Total knee replacement (TKR) is an effective operation for many patients, however approximately 20% of patients experience chronic pain and functional limitations in the months and years following their TKR. If modifiable pre-operative risk factors could be identified, this would allow patients to be targeted with individualised care to optimise these factors prior to surgery and potentially improve outcomes. Psychosocial factors have also been found to be important in predicting outcomes in the first 12 months after TKR, however their impact on long-term outcomes is unknown. This study aimed to identify pre-operative psychosocial predictors of patient-reported and clinician-assessed outcomes at one year and five years after primary TKR. Patients and methods. 266 patients listed for a Triathlon TKR because of osteoarthritis were recruited from pre-operative assessment clinics at one orthopaedic centre. Knee pain and function were assessed pre-operatively and at one and five years post-operative using the WOMAC Pain score, WOMAC Function score and American Knee Society Score (AKSS) Knee score. Pre-operative depression, anxiety, catastrophizing, pain self-efficacy and social support were assessed using patient-reported outcome measures. Statistical analyses were conducted using multiple linear regression and mixed effect linear regression, and adjusted for confounding variables. Results. Higher anxiety was a predictor of worse self-reported pain at one year post-operative. Higher anxiety and catastrophizing were predictive of worse self-reported function at one year post-operative. No psychosocial factors were associated with any outcome measures at five years post-operative. Analysis of change over time found that patients with higher pain self-efficacy had lower pre-operative pain and experienced less improvement in pain up to one year. Higher pain self-efficacy was associated with less improvement in the AKSS up to one year post-operative but more improvement between one and five years post-operative. Conclusion. This study found that pre-operative anxiety and catastrophizing influence outcomes at one year after TKR, highlighting that some patients may benefit from targeted psychological interventions to reduce these risk factors and improve outcomes. However, none of the psychosocial variables assessed were predictors of outcomes at five years post-operative, suggesting that the negative effects of anxiety and catastrophizing on outcome do not persist in the longer term

Introduction. Following primary total knee arthroplasty (TKA), patients experience pain relief and report improved physical function and activity. However, there is paucity of evidence that patients are truly more active in daily life after TKA. The aims of this study were: 1) to prospectively measure physical activity with a wearable motion sensor before and after TKA; 2) to compare patient-reported levels of physical activity with objectively assessed levels of physical activity before and after TKA; 3) to investigate whether differences in physical activity after TKA are related to levels of physical function. Methods. 22 patients (age=66.6 ±9.3yrs; m/f= 12/11; BMI= 30.6 ±6.1) undergoing primary TKA (Vanguard, ZimmerBiomet), were measured preoperatively and 1–3 years postoperatively. Patient-reported outcome measures (PROMs) included KOOS-PS and SQUASH for assessment of perceived physical function and activity resp. Physical activity was assessed during 4 consecutive days in patients” home environments while wearing an accelerometer-based activity monitor (AM) at the thigh. All data were analysed using semi-automated algorithms in Matlab. AM-derived parameters included walking time (s), sitting time (s) standing time (s), sit-to-stand transfers, step count, walking bouts and walking cadence (steps/min). Objective physical function was assessed by motion analysis of gait, sit-to-stand (STS) transfers and block step-up (BS) transfers using a single inertial measurement unit (IMU) worn at the pelvis. IMU-based motion analysis was only performed postoperatively. Statistical comparisons were performed with SPSS and a per-protocol analysis was applied to present the results at follow-up. Results. Data were available for 17 of 22 patients at follow-up. PROMs demonstrated significant improvement of perceived physical function (KOOS-PS=68±21 vs. 34±26; p<0.001) and physical activity (SQUASH=2584 ±1945 vs. 3038 ±2228; p<0.001) following TKA. AM-based parameters of physical activity demonstrated no significant differences between pre- and postoperative quantitative outcomes. Only the qualitative outcome of walking cadence significantly changed after TKA (81.41 ±10.86 (steps/min) vs. 94.24 ±7.20 resp.; p<0.001). There were moderate correlations between self-reported and objectively assessed levels of physical activity after TKA (Pearson”s r=0.36–0.43; p<0.05). Outcomes of physical activity after TKA were moderately correlated to IMU-based functional outcome measures (Pearson”s r = 0.31 – 0.48; p<0.05). Conclusion. 1–3 years after TKA, patients demonstrate improved function. However, the self-perceived higher activity level (+18%) after TKA is not supported by any objective data obtained by wearable motion sensors such as steps, transfers or time-on-feet. This may have implications for general health and requires further investigation into patient communication, expectation management or motivational intervention

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

Physical functioning in patients undergoing hip surgery is commonly assessed in three ways: patient-reported outcome measure (PROM), performance test, or clinician-administered measure. It is recommended that several types of measures are used concurrently to capture an extended picture of function. Patient fatigue and burden, time, resources and logistical constraints of clinic and research appointments mean that collecting multiple measures is seldom feasible, leading to focus on a limited number of measures, if not a single one. While there is evidence that performance-tests and PROMs do not fully correlate, correlations between PROMs, performance tests and clinician-administrated measures are yet to be evaluated. It is also not known if the associations between function and patient characteristics depend on how function is measured. The aim of our study was to use different measures to assess function in the same group of patients before their hip surgery to determine 1. how well PROMs, performance tests and clinician-administrated measures correlate with one another and 2. Whether these measures are associated with the same patient characteristics. We conducted a cross-sectional analysis of the pre-operative information of 125 participants listed for hip replacement. The WOMAC function subscale, Harris Hip Score (HHS) and walk-, step- and balance-tests were assessed by questionnaire or during a clinic visit. Participant socio-demographics and medical characteristics were also collected. Correlations between functional measures were investigated with correlation coefficients (r). Regression models were used to test the association between the patient's characteristics and each of the three types of functional measures. None of the correlations between the PROM, clinician-administrated measure and performance tests were very high (r<0.90). The highest correlations were found between the WOMAC-function and the HHS (r=0.7) or the Walk-test (r=0.6), and between the HHS and the walk-test(r=0.7). All the other performance-tests had low correlations with the other measures(r ranging between 0.3 and 0.5). The associations between patient characteristics and functional scores varied by type of measure. Psychological status was associated with the WOMAC function (p-value<0.0001) but not with the other measures. Age was associated with the performance test measures (p-value ranging from ≤0.01 to <0.0001) but not with the WOMAC function. The clinician-administered (HHS) measure was not associated with age or psychological status. When evaluating function prior to hip replacement clinicians and researchers should be aware that each assessment tool captures different aspects of function and that patient characteristics should be taken into account. Psychological status influences the perception of function; patients may be able to do more than they think they can do, and may need encouragement to overcome anxiety. A performance test like a walk-test would provide a more comprehensive assessment of function limitations than a step or balance test, although performance tests are influenced by age. For the most precise description of functional status a combination of measures should be used. Clinicians should supplement their pre-surgery assessment of function with patient-reported measure to include the patient's perspective

Objectives. Electronic forms of data collection have gained interest in recent years. In orthopaedics, little is known about patient preference regarding pen-and-paper or electronic questionnaires. We aimed to determine whether patients undergoing total hip (THR) or total knee replacement (TKR) prefer pen-and-paper or electronic questionnaires and to identify variables that predict preference for electronic questionnaires. Methods. We asked patients who participated in a multi-centre cohort study investigating improvement in health-related quality of life (HRQoL) after THR and TKR using pen-and-paper questionnaires, which mode of questionnaire they preferred. Patient age, gender, highest completed level of schooling, body mass index (BMI), comorbidities, indication for joint replacement and pre-operative HRQoL were compared between the groups preferring different modes of questionnaire. We then performed logistic regression analyses to investigate which variables independently predicted preference of electronic questionnaires. Results. A total of 565 THR patients and 387 TKR patients completed the preference question. Of the THR patients, 81.8% (95% confidence interval (CI) 78.4 to 84.7) preferred pen-and-paper questionnaires to electronic questionnaires, as did 86.8% (95% CI 83.1 to 89.8) of TKR patients. Younger age, male gender, higher completed level of schooling and higher BMI independently predicted preference of electronic questionnaires in THR patients. Younger age and higher completed level of schooling independently predicted preference of electronic questionnaires in TKR patients. Conclusions. The majority of THR and TKR patients prefer pen-and-paper questionnaires. Patients who preferred electronic questionnaires differed from patients who preferred pen-and-paper questionnaires. Restricting the mode of patient-reported outcome measures to electronic questionnaires might introduce selection bias. Cite this article: Bone Joint Res 2013;2:238–44

To validate the Modified Forgotten Joint Score (MFJS) as a new patient-reported outcome measure (PROM) in hip and knee arthroplasty against the UK's gold standard Oxford Hip and Knee Scores (OHS/OKS). The original Forgotten Joint Score was created by Behrend et al to assess post-op hip/knee arthroplasty patients. It is a new assessment tool devised to provide a greater discriminatory power, particularly in the well performing patients. It measures an appealing concept; the ability of a patient to forget about their artificial joint in everyday life. The original FJS was a 12-item questionnaire, which we have modified to 10-items to improve reliability and missing data. Postal questionnaires were sent out to 400 total hip/knee replacement (THR/TKR) patients who were 1–2 years post-op, along with the OHS/OKS and a visual pain analog score. The data collected from the 212 returned questionnaires (53% return rate) was analysed in relation to construct and content validity. A sub-cohort of 77 patients took part in a test-retest repeatability study to assess reliability of the MFJS. The MFJS proved to have an increased discriminatory power in high-performing patients in comparison to the OHS and OKS, highlighted by its more normal frequency of distribution and reduced ceiling effects in the MFJS. 30.8% of patients (n=131) scored 42–48 (equivalent to 87.5–100 in the MFJS) or more in the OKS compared to just 7.69% in the MFJS TKR patients. The MFJS proved to have an increased test-retest repeatability based upon its intra-class correlation coefficient of 0.968 compared to the Oxford's 0.845. The MFJS provides a more sensitive tool in the assessment of well performing hip and knee arthroplasties in comparison to the OHS/OKS. The MFJS tests the concept of awareness of a prosthetic joint, rather than pain and function and therefore should be used as adjunct to the OKS/OHS

Summary Statement. A prospective randomised evaluation of primary TKA utilizing patient specific instruments demonstrated great accuracy of bone resection, improved sagittal alignment and the potential to improve functional outcomes and reduce operating room costs when compared to standard TKA instrumentation. Introduction. Patient specific instruments (PSI), an alternative to standard total knee arthroplasty (TKA) technology, have been proposed to improve the accuracy of TKA implant placement and post-operative limb alignment. Previous studies have shown mixed results regarding the effectiveness of PSI. The purposes of this study were (1) to evaluate the accuracy of the pre-operative predicted PSI plan compared to intra-operative TKA resection measurements, (2) to compare patient-reported outcome measures of PSI and standard TKA patients, and (3) to compare the incremental cost savings with PSI. Patients and Methods. This randomised, prospective pilot study of 19 patients undergoing primary TKA with a cruciate-retaining cemented prosthesis (NexGen, Zimmer Inc.) was conducted by a single high-volume arthroplasty surgeon (DCA). Patients were randomised to PSI or standard instrumentation. Patients randomised to the PSI cohort received a pre-operative knee MRI for PSI fabrication using Zimmer proprietary software. 10 standard TKA and 9 PSI TKA were completed. Pre-operative baseline SF-36 and WOMAC scores were collected. Operative data collected included operating room times, implant details, femoral (medial/lateral distal and posterior) and tibial (medial/lateral) cut thicknesses, and number of instrument trays used. Hospitalization data collected included length of stay, blood loss, drain output, and transfusion requirements. Follow-up occurred at 2 weeks, 6–8 weeks, 3 months, 6 months, and 1 year, with SF-36 and WOMAC scores collected at each time point. Routine radiographic analysis was carried out in both cohorts. Extensive financial data was collected including costs of operating room use and anesthesia, implants, and hospitalization. Statistical analyses included t-tests for continuous variables and chi-square tests for categorical variables. Results. All femoral and tibial implant sizes used during TKA matched the component sizes predicted by the PSI software. Flexion gap bone resection (posterior medial/lateral femoral cuts) was extremely accurate (<1 mm on average) when compared with PSI predictions. PSI proximal tibial bone resection was also extremely accurate and within 1 mm on average of predicted values. Sagittal plane tibial component posterior slope in PSI TKA was significantly more accurate (7.33 degrees) in comparison to standard instrumentation (4.20 degrees) (p<0.025). No significant differences in coronal mechanical limb alignment existed between the two cohorts (p>0.05). There were no differences in operating room times, length of stay, or transfusions between the two groups. PSI patients used 4 fewer instrument trays per case (p<0.0001). There were no significant differences in functional outcome scores between the two groups (p>0.05). Discussion/Conclusion. PSI TKA demonstrated outstanding accuracy in bone resection when compared with the custom operative plan. There was no difference in post-operative coronal limb alignment or individual component alignment between the two groups, but an improvement in tibial component alignment in the sagittal plane in the PSI cohort was statistically significant. The number of instrument trays in PSI TKA's were significantly less than standard TKA which led to less cost for instrument sterilization and assembly, and quicker room set-up. PSI instrumentation resulted in accurate bone resection and appropriate limb and component alignment after primary TKA in this prospective randomised evaluation