Smaller studies indicate that yoga may be an effective treatment for chronic low back pain. We conducted a randomised trial to evaluate if yoga compared to usual care improves back function in patients with chronic or recurrent low back pain. Outcomes were assessed by postal questionnaires. The setting was 13 non-National Health Service premises. We recruited 313 adults with chronic or recurrent low back pain from primary care. 157 were randomised to usual care. 156 were randomised to a 12-class, gradually-progressing programme of yoga delivered by 12 teachers over three months. All received The Back Book. Primary outcome was back function (Roland Morris Disability Score) at three months. Secondary outcomes: back function at six and 12 months, back pain, pain self-efficacy and general health. Back function improved more in the yoga group: mean difference in changes from baseline at three (−2.17, 95% CI −3.31 to −1.03, p<0.001), six (−1.48, 95% CI −2.62 to −0.33, p=0.011) and 12 months (−1.57, −2.71 to −0.42, p=0.007). Improvement in pain self-efficacy at three and six months in the yoga group. No differences in general health and pain reduction. Two adverse events were reported by controls and 12 by the yoga group – 8 out of 12 reported pain which may have been due to yoga. 63 (40%) were not fully compliant with treatment and 23 (15%) did not attend any yoga classes.Purposes of the study and background
Summary of the methods used and the results
Hip resurfacing has generally been used in younger patients with early osteoarthritis of the hip. There has been considerable recent interest in this over the past few years. We conducted a prospective randomised trial comparing 2 hip resurfacing implants, Durom and ASR looking at radiological and clinical outcomes. Forty-nine patients (78% male) with hip osteoarthritis which met the criteria for hip resurfacing were randomised to receive either a Durom or ASR resurfacing implant. These patients have so far been followed up for a minimum of one year. The groups were comparable in age (p=0.124) and gender (p=0.675). The average age in the ASR group was 54.04 years and in the Durom group it was 51.25. Radiological views were scrutinised immediately post op and at final follow up so far to look at cup inclination, stem-shaft angle, and acetabular osseointegration. Clinical outcomes were compared using the Oxford hip scores, WOMAC scores and SF12 scores. At minimum follow up of 1 year the mean post operative Oxford hip score was not significantly different between the Durom (45.32, SD 3.93) and ASR (43.44, SD 8.44). The mean post operative WOMAC score was also not significantly different between the Durom (52.56, SD 6.06) and ASR (49.63, SD 2.23). There was no difference between the groups with regards to signs of osseointegration from radiological assessment (p=0.368). There were 3 periprosthetic femoral neck fractures (5.7%) and one revision for pain. We conclude from this trial that there is no difference in the clinical or radiological findings between the Durom and ASR implants.
Prosthesis migration and acetabular cup wear are useful short term measurement which may predict later implant outcome. However, the significance of the magnitude and pattern of the migration is very much dependent on the specific design studied. This study aimed to characterise patterns of migration by following four cemented femoral stem designs using Radiostereometry (RSA) within a prospective randomised longitudinal trial. 164 patients undergoing cemented femoral hip replacement for osteoarthritis were randomised to receive either an Exeter (Howmedica Stryker), Ultima Tapered Polished Stem (TPS) (Depuy), Ultima Straight Stem (USS) (Johnson and Johnson) or Elite Plus (Depuy) stem. Each subject received the OGEE PE cemented acetabular component (Depuy). RSA examinations were performed at 1 week and 6, 12, 18, 24 and 60 months post surgery. They were analysed using the UMRSA system (RSA Biomedical AB, Umea, Sweden), and our local geometric stem measurement software. 149 patients had RSA measurements available to 2 years, and 96 patients to 5 years. Differences were analysed using mixed linear modelling (SPSS). Median linear proximal cup wear rate reduced to a minimum of 0.02-0.06mm/year in year two. Between 2 and 5 years the wear rate increased, being significantly higher for the Elite. Cup migration was small but continuous. At 2 years it was median 0.3mm proximally, increasing to 0.5 mm at 5 years. Median rotations were less than 0.3 degrees. Proximal migration was positive and increasing at all time points for all stems. For the tapered polished designs, while the overall magnitude was significantly higher, the rate of migration significantly decreased, whereas for the other stem designs it did not. The TPS stem showed a tendency for posterior tilt which was significant compared to the other stems at 5 years. All stems tended to retroversion, with the USS significantly less than the others and the Elite showing and relative increase at 5 years. In summary migration patterns are characterised by the stem design, including where there were only small changes between designs. We are now testing measured migrations as predictors of outcome, and will continue to follow this group of patients to 10 years.
This study sought to determine whether the functional outcome of two common spinal operations could be improved by a programme of post-operative rehabilitation and/or an educational booklet each compared with usual care. This was a multi-centre, factorial, randomised controlled trial on the post operative management of spinal surgery patients, with randomisation stratified by surgeon and operative procedure. The study compared the effectiveness of a rehabilitation programme and an education booklet for the postoperative management of patients undergoing discectomy or lateral nerve root decompression surgery, each compared with “usual care” using a 2 × 2 factorial design, randomising patient to four groups; rehabilitation-only, booklet-only, rehabilitation-plus-booklet, and usual care only. The primary outcome measure was the Oswestry Disability Index (ODI) at 12 months, with secondary outcomes including visual analogue scale measures of back and leg pain. An economic analysis was also performed.Introduction
Methods
To compare the efficacy and safety of balloon kyphoplasty (BKP) to non-surgical management (NSM) over 24 months in patients with acute painful fractures by clinical outcomes and vertebral body kyphosis correction and surgical parameters. Three hundred Adult patients with one to three VCF's were randomised within 3 months of the acute fracture; 149 to Balloon Kyphoplasty and 151 to Non-surgical management. Subjective QOL assessments and objective functional (Timed up and go [TUG]) and vertebral body kyphotic angulation (KA), were assessed over 24 months; we also report surgical parameters and adverse events temporally related to surgery (within 30-days).Purpose
Material and Methods
Whether it is best to retain the posterior cruciate ligament in the degenerated knee, i.e. using a cruciate-retaining (CR) total knee prosthesis (TKP), or to use a more constraint posterior-stabilized (PS) TKP is of debate. There are limited studies comparing the effect of both methods on implant fixation and clinical outcome, leaving it up to the surgeon to base this decision on anything but conclusive evidence. We assessed the effect of two different philosophies in knee arthroplasty on clinical outcome and tibial component migration measured with radiostereometric analysis (RSA), by directly comparing the CR and PS version of an otherwise similarly designed cemented TKP. Sixty patients were randomized and received a Triathlon TKP (Stryker, NJ, USA) of either CR (n=30) or PS (n=30) design. RSA measurements (primary outcome) and clinical scores including the Knee Society Score and Knee injury and Osteoarthritis Outcome Score were evaluated at baseline, at three months postoperatively and at one, two, five and seven years. A linear mixed-effects model was used to analyse the repeated measurements. Both groups showed a similar implant migration pattern, with a maximum total point motion at seven years follow-up of around 0.8 mm of migration (mean difference between groups 95% CI −0.11 to 0.15mm, p=0.842). Two components (one of each group) were considered to have an increased risk of aseptic loosening. Both groups improved equally after surgery on the KSS and KOOS scores and no differences were seen during the seven years of follow-up. No differences in implant migration nor clinical results were seen seven years after cruciate-retaining compared to posterior-stabilized total knee prostheses.
The postoperative course of median nerve decompression in the carpal tunnel syndrome may sometimes be complicated by postoperative pain, paresthesias, and other unpleasant symptoms, or be characterized by a slow recovery of nerve function due to prolonged preoperative injury causing extensive nerve damage. The aim of this study is to explore any possible effects of alpha lipoic acid (ALA) in the postoperative period after surgical decompression of the median nerve at the wrist. Patients were enrolled with proven carpal tunnel syndrome and randomly assigned into one of two groups: Group A: surgical decompression of the median nerve followed by ALA for 40 days. Group P: surgical decompression followed by placebo. The primary endpoint of the study was nerve conduction velocity at 3 months post surgery, Other endpoints were static 2 point discrimination, the Boston score for hand function, pillar pain and use of pain killers beyond the second postoperative day. ALA did not show to significantly improve nerve conduction velocity or Boston score. However, a statistically significant reduction in the postoperative incidence of pillar pain was noted in Group A. In addition, static 2 point discrimination showed to be significantly improved by ALA. Administration of ALA following decompression of the median nerve for carpal tunnel release is effective on nerve recovery, although this is not detectable through nerve conduction studies but in terms of accelerated and improved static two-point discrimination. The use of ALA as a supplementation for nerve recovery after surgical decompression may be extended to all types of compression syndromes or conditions where a nerve is freed from a mechanical insult. Furthermore, ALA limits post-decompression pain, including late pericicatricial pain at the base of the palm, the so called pillar pain, which seems to be associated with a reversible damage to the superfical sensitive small nerve fibers. In conclusion postoperative administration of ALA for 40 days post-median nerve decompression was positively associated with nerve recovery, induced a lower incidence of postoperative pillar pain and was associated with a more rapid improvement of static two-point discrimination. This treatment is well tolerated and associated with high levels of satisfaction and compliance, supporting its value as a standard postoperative supplementation after carpal tunnel decompression.
Total hip replacement (THR) is a common elective surgical procedure and can be effective for reducing chronic pain. However, waiting times for THR can be considerable, and patients often experience significant pain during this time. A pain self-management intervention may provide patients with the skills to enable them to manage their pain and its impact more effectively before surgery. However, studies of arthritis self-management programmes have faced challenges because of low recruitment rates, poor intervention uptake, and high attrition rates. This study aimed to evaluate the feasibility of a randomised controlled trial (RCT) to assess the effectiveness and cost-effectiveness of a group-based pain self-management course for patients undergoing THR. Specific objectives were to assess trial design, ascertain recruitment and retention rates, identify barriers to participation, refine data collection methods, and evaluate uptake and patient satisfaction with the course. Patients listed for THR in an elective orthopaedic centre Bristol, UK were sent a postal invitation about the study. Participants were randomised to attend a pain self-management course plus standard care or standard care only using a computer-generated randomisation system. The pain self-management course was delivered by Arthritis Care and consisted of two half-day group sessions prior to surgery and one full-day group session 2–4 months after surgery. A structured course evaluation questionnaire was completed by participants. Outcomes assessment was by postal questionnaire prior to surgery and 1-month, 3-months and 6-months after surgery. Self-report resource use data were collected using a diary prior to surgery and inclusion of resource use questions in the 3-month and 6-month post-operative questionnaires. Brief telephone interviews were conducted with non-participants to explore barriers to participation. Postal invitations were sent to 385 eligible patients and 88 patients consented to participate (23% recruitment rate). Participants had a mean age of 66 years and 65% were female. Brief interviews with 57 non-participants revealed the most common reasons for non-participation were perceptions about the intervention and difficulties in getting to the hospital for the course. Of the 43 patients randomised to the intervention group, 28 attended the pre-operative pain self-management sessions and 11 attended the post-operative sessions. Participant satisfaction with the course was high, and patients enjoyed the group format. Retention of participants was acceptable, with 83% completing follow-up. Questionnaire return rates were high (76–93%), with the exception of the pre-operative resource use diary (35%). Completion rates for the resource use questions varied by category and allowed for an economic perspective from the health and social care payer to be taken. Undertaking feasibility work for a RCT is labour-intensive; however this study highlights the importance of conducting such work. Postal recruitment resulted in a low recruitment rate and brief interviews with non-participants provided valuable information on barriers to participation. Embedding collection of resource use data within questionnaires resulted in higher completion rates than using resource use diaries. While patients who attended the course gave positive feedback, attendance was low. Findings from this feasibility study enable us to design successful definitive group-based RCTs in the future.
Primary mechanical stability is important with uncemented THR because early migration is reduced, leading to more rapid osseointegration between the implant and bone. Such primary mechanical stability is provided by the design features of the device. The aim of this study was to compare the migration patterns of two uncemented hip stems, the Furlong Active and the Furlong HAC stem; the study was designed as a randomised control trial. The implants were the Furlong HAC, which is an established implant with good long term results, and the Furlong Active, which is a modified version of the Furlong HAC designed to minimise stress concentrations between the implant and bone, and thus to improve fixation. The migration of 43 uncemented femoral components for total hip replacement was measured in a randomised control trial using Roentgen Stereophotogrammetric Analysis (RSA) over two years. Twenty-three Furlong HAC and twenty Furlong Active stems were implanted into 43 patients. RSA examinations were carried out post-operatively, and at six months, 12 months and 24 months post-operatively. The patients stood in-front of a purpose made calibration frame which contained accurately positioned radio-opaque markers. From the obtained images, the 3-D positions of the prosthesis and the host bone were reconstructed. Geometrical algorithms were used to identify the components of the implant. These algorithms allowed the femoral component to be studied without the need to attach markers to the prosthesis. The migration was calculated relative to the femoral coordinate system representing the anterior-posterior (A-P), medial-lateral (M-L) and proximal-distal (P-D) directions respectively. Distal migration was termed subsidence.Introduction
Materials and methods
Alignment results did not differ between PSG and conventional instrumentation. A small reduction in operation time and blood loss was found with the PSG system, but is unlikely of clinical significance. Length of hospital stay was identical for both groups. Several techniques for aligning a TKA exist nowadays. Patient-specific guiding (PSG) has relatively recently been introduced to try to resolve the shortcomings of existing techniques while optimising the operative procedure. Still few reports have been published on the clinical outcome and on the peroperative results of this new technique. This prospective, double-blind, randomised controlled trial was designed to address the following research questions: 1. Is there a significant difference in outliers in alignment in the frontal and sagittal plane between PSG TKA and conventional TKA. 2. Is there a significant difference in operation time, blood loss and length of hospital stay between the 2 techniques.Summary
Introduction
Robust evidence on the effectiveness of peri-operative local anaesthetic infiltration (LAI) is required before it is incorporated into the pain management regimen for patients receiving total knee replacement (TKR). To assess the effectiveness of peri-operative LAI for pain management in patients receiving TKR we conducted a systematic review, fully powered randomised controlled trial (RCT) and economic evaluation. We searched MEDLINE, Embase and Cochrane databases for RCTs of peri-operative LAI in patients receiving TKR. Two reviewers screened abstracts and extracted data. Outcomes were pain, opioid use, mobilisation, hospital stay and complications. Authors were contacted if required. When feasible, we conducted meta-analysis with studies analysed separately if a femoral nerve block (FNB) was provided. In the APEX RCT, we randomised 316 patients awaiting TKR to standard anaesthesia which included FNB, or to the same regimen with additional peri-operative LAI (60mls 0.25% bupivacaine plus adrenaline). Post-operatively, all patients received patient-controlled morphine. The primary outcome was joint pain severity (WOMAC-Pain) at 12 months. Patients and outcome assessors were blinded to allocation. Within APEX, cost-effectiveness was assessed from the health and social-care perspective in relation to quality adjusted life years (QALYs) and WOMAC-Pain at 12-months. Resource use was collected from hospital records and patient questionnaires. In the systematic review, 23 studies including 1,439 patients were identified. Compared with patients receiving no intervention, LAI reduced WOMAC-Pain by standardised mean difference (SMD) −0.40 (95%CI −0.58, −0.22; p<0.001) at 24 hours at rest and by SMD −0.27 (95%CI −0.50, −0.05; p=0.018) at 48 hours during activity. In three studies there was no difference in pain at any time point between randomised groups where all patients received FNB. Patients receiving LAI spent fewer days in hospital, used less opioids and mobilised earlier. Complications were similar between groups. Few studies reported long-term outcomes. In the APEX RCT, pain levels in hospital were broadly similar between groups. Overall opioid use was similar between groups. Time to mobilisation and discharge were largely dependent on local protocols and did not differ between groups. There were no differences in pain outcomes between groups at 12 months. In the economic evaluation, LAI was marginally associated with lower costs. Using the NICE £20,000 per QALY threshold, the incremental net monetary benefit was £264 (95%CI, −£710, £1,238) and the probability of being cost-effective was 62%. Although LAI appeared to have some benefit for reduced pain in hospital after TKR there was no evidence of pain control additional to that provided by femoral nerve block, however it would be cost-effective at the current NICE thresholds.
Robust evidence on the effectiveness of peri-operative local anaesthetic infiltration (LAI) is required before it is incorporated into the pain management regimen for patients receiving total hip replacement (THR). We assessed the effectiveness of LAI using a systematic review and a fully powered randomised controlled trial (RCT) with economic evaluation. We searched MEDLINE, Embase and Cochrane databases for RCTs of peri-operative LAI in patients receiving THR. Two reviewers screened abstracts, extracted data, and liaised with authors. Outcomes were pain, opioid use, mobilisation, hospital stay and complications. If feasible, we conducted meta-analysis. In the APEX RCT, we randomised 322 patients awaiting THR to receive additional peri-operative LAI (60mls 0.25% bupivacaine plus adrenaline) or standard anaesthesia alone. Post-operatively, all patients received patient-controlled morphine. The primary outcome was joint pain severity (WOMAC-Pain) at 12 months. Patients and outcome assessors were blinded to allocation. Within APEX, cost-effectiveness was assessed from the health and social-care perspective in relation to quality adjusted life years (QALYs) and WOMAC-Pain at 12-months. Resource use was collected from hospital records and patient questionnaires. In the systematic review, we identified 13 studies (909 patients). Patients undergoing THR receiving LAI experienced greater pain reduction at 24 hours at rest, standardised mean difference (SMD) −0.61 (95%CI −1.05, −0.16; p=0.008) and at 48 hours during activity, SMD −0.43 (95%CI −0.78, −0.09; p=0.014). Patients receiving LAI spent fewer days in hospital, used less opioids and mobilised earlier. Complications were similar between groups. Long-term outcomes were not a focus of these studies. In the APEX RCT, pain levels in hospital were broadly similar between groups, probably due to patient-controlled analgesia. Opioid use was similar between groups. Time to mobilisation and discharge were largely dependent on local protocols and did not differ between groups. Patients receiving LAI were less likely to report severe pain at 12 months than those receiving standard care, odds ratio 10.2 (95%CI 2.1, 49.6; p=0.004). Complications were similar between groups. In the economic evaluation, LAI was associated with lower costs and greater cost-effectiveness than standard care. Using a £20,000 per QALY threshold, the incremental net monetary benefit was £1,125 (95%CI £183, £2,067) and the probability of being cost-effective was greater than 98 %. The evidence suggests that peri-operative LAI is a cost-effective intervention for reducing acute and chronic post-surgical pain after THR.
Decreased oxygenation and delayed wound healing may negate the advantages of using a medial parapatellar incision in Total Knee Replacement. Tissue biochemical and blood flow data are not currently available in the literature. 20 patients were included in the study and randomised to midline or medial parapatellar skin incision groups, being supervised by one of 3 Consultant surgeons. Cutaneous blood flow was measured using a Speckle Contrast Blood Perfusion Imager at pre-operative and Days 1 & 3 post-operative intervals. Interstitial fluid measurements for lactate, pyruvate, lactate/pyruvate ratio and glucose were obtained from subcutaneous catheters with a dialysis membrane. Pre-operative samples were obtained from a catheter inserted into the prospective lateral wound edge. A catheter inserted after wound closure supplied dialysates at 0.5, 1, 2, 4, 6, 12 and 24-hour intervals. One catheter was corrupted on insertion; therefore the patients with biochemical data numbered 19. Cutaneous blood flow improved over the 3 post-operative days in both types of incision and both sides, the medial retaining comparatively better flow. At Day 3, the parapatellar incision group displayed better flow on both sides of the wound. The concentration of lactate was highest in the parapatellar incision group of patients at all intervals. Pyruvate concentrations did not appear to differ across the incision types. Similarly, glucose concentrations did not appear to differ until after 4 hours, when higher concentrations were recorded in the midline group. Lactate/pyruvate ratio appeared to be notably greater in the parapatellar incision group. Plotting change in blood flow relative to change in lactate concentration demonstrated an increase in lactate as flow deteriorates. The study findings suggest medial parapatellar incisions have increased anaerobic metabolites due to tissue hypoperfusion. Previous studies have demonstrated decreased oxygen tension in lateral based flaps and more recently the medial to lateral arterial anatomy has been demonstrated.
Currently, the cement being used for hemiarthroplasties and total hip replacements by the authors and many other surgeons in the UK is Palacos® (containing 0.5g Gentamicin). Similar cement, Copal® (containing 1g Gentamicin and 1g Clindamycin) has been used in revision arthroplasties, and has shown to be better at inhibiting bacterial growth and biofilm formation. We aim to investigate the effect on SSI rates of doubling the gentamicin dose and adding a second antibiotic (clindamycin) to the bone cement in hip hemiarthroplasty. We randomised 848 consecutive patients undergoing cemented hip hemiarthroplasty for fractured NOF at one NHS trust (two sites) into two groups: Group I, 464 patients, received standard cement (Palacos®) and Group II, 384 patients, received high dose, double antibiotic-impregnated cement (Copal®). We calculated the SSI rate for each group at 30 days post-surgery. The patients, reviewers and statistician were blinded as to treatment group. The demographics and co-morbid conditions (known to increase risk of infection) were statistically similar between the groups. The combined superficial and deep SSI rates were 5 % (20/394) and 1.7% (6/344) for groups I and II respectively (p=0.01). Group I had a deep infection rate 3.3 %(13/394) compared to 1.16% (4/344) in group II (p=0.082). Group I had a superficial infection rate 1.7 % (7/394) compared to 0.58% (2/344) in group II (p=0.1861). 33(4%) patients were lost to follow up, and 77 (9%) patients were deceased at the 30 day end point. There was no statistical difference in the 30 day mortality, C. difficile infection, or the renal failure rates between the two groups. Using high dose double antibiotic-impregnated cement rather than standard low dose antibiotic-impregnated cement significantly reduced the SSI rate (1.7% vs 5%; p=0.01) after hip hemiarthroplasty for fractured neck of femur in this prospective randomised controlled trial.
One untested back pain treatment model is to stratify management depending on prognosis (low, medium or high-risk). This 2-arm RCT investigated: (i) overall clinical and cost-effectiveness of stratified primary care (intervention), versus non-stratified current best practice (control); and (ii) whether low-risk patients had non-inferior outcomes, and medium/high-risk groups had superior outcomes. 1573 adults with back pain (+/− radiculopathy) consulting at 10 general practices in England responded to invitations to attend an assessment clinic, at which 851 eligible participants were randomised (intervention n=568; control n=283). Primary outcome using intention-to-treat analysis was the difference in change in the Roland-Morris Disability Questionnaire (RMDQ) score at 12 months. Secondary outcomes included 4-month RMDQ change between arms overall, and at risk-group level at both time-points. The economic evaluation estimated incremental quality-adjusted life years (QALYs) and back pain-related health care costs.Background
Methods
Background. Proximal femoral fracture is a common, major health problem resulting in loss of functional independence and a high cost burden on society. Rehabilitation can potentially maximise functional recovery, but evidence of effectiveness is lacking. An enhanced rehabilitation intervention designed to improve self-efficacy and increase the amount and quality of practice of physical exercise and activities of daily living has been developed consisting of patient held workbooks and extra therapy sessions in the community. This study aims to define characteristics of the cohort of individuals this intervention is targeted to, assess acceptability of the intervention and feasibility of recruiting participants for a larger scale trial. Methods. An anonymous cohort study of all proximal femoral fracture patients admitted to three acute hospitals will provide details on residence pre-admission, type of fracture, type of surgery, adverse events and subsequent readmissions. A separate randomised feasibility study recruiting participants from this cohort will assess acceptability and feasibility of the study in terms of eligibility, recruitment, reasons for decline, retention and outcome measure completion. The success rate of identifying patients for the feasibility study and whether the recruited participants are representative of the cohort population will be evaluated by comparison of the feasibility participant screening and background data with that of the cohort. Results. 541 patients were screened for the feasibility study between June 2014 and February 2015 (ongoing). 298 were ineligible, 243 were eligible and 53 (22%) have been recruited to date. Lack of capacity is the leading cause of ineligibility and burden of taking part is perceived as a significant block to participation. Completion rate of outcome measures is high at baseline and follow up. Conclusions. Recruitment from the acute setting is challenging. However, study processes, outcome measurement and intervention is well tolerated by participants. Level of Evidence. I - Well conducted
Abstract. Background. Recruitment of patients to participate in
Background. This article reviews four commonly used approaches to assess patient responsiveness to a treatment or therapy [Return To Normal (RTN), Minimal Important Difference (MID), Minimal Clinically Important Difference (MCID), OMERACT-OARSI (OO)], and demonstrates how each of the methods can be formulated in a multi-level modelling (MLM) framework. Methods. Data from the Arthroplasty Pain Experience (APEX) cohort study was used. Patients undergoing total hip and knee replacement completed the Intermittent and Constant Osteoarthritis Pain (ICOAP) questionnaire prior to surgery and then at 3, 6 and 12 months after surgery. We compare baseline scores, change scores, and proportion of individuals defined as “responders” using traditional and multi-level model (MLM) approaches to patient responsiveness. Results. Using existing approaches, baseline and change scores are underestimated, and the variance of baseline and change scores overestimated in comparison to MLM approaches. MLM increases the proportion of individuals defined as responding in RTN, MID, and OO criteria compared to existing approaches. Using MLM with the MCID criteria reduces the number of individuals identified as responders. Conclusion. MLM improves the estimation of the standard deviation of baseline and change scores by explicitly incorporating measurement error into the model, and avoiding regression to the mean when making individual predictions. Using refined definitions of responsiveness may lead to a reduction in misclassification when attempting to predict who does and does not respond to an intervention, and clarifies the similarities between existing methods. Approvals. The APEX trials were registered as an International Standardised
Background. Chronic pain after joint replacement is common, affecting approximately 10% of patients after total hip replacement (THR) and 20% of patients after total knee replacement (TKR). Heightened generalised sensitivity to nociceptive input could be a risk factor for the development of this pain. The primary aim of this study was to investigate whether preoperative widespread pain sensitivity was associated with chronic pain after joint replacement. Methods. Data were analysed from 254 patients receiving THR and 239 patients receiving. TKR. Pain was assessed preoperatively and at 12 months after surgery using the Western Ontario and McMaster Universities Osteoarthritis Pain Scale. Preoperative widespread pain sensitivity was assessed through measurement of pressure pain thresholds (PPTs) at the forearm using an algometer. Statistical analysis was conducted using linear regression and linear mixed models, and adjustments were made for confounding variables. Results. In both the THR and TKR cohort, lower PPTs (heightened widespread pain. sensitivity) were significantly associated with higher preoperative pain severity. Lower PPTs were also significantly associated with higher pain severity at 12 months after surgery in the THR cohort. However, PPTs were not associated with the change in pain severity from preoperative to 12 months postoperative in either the TKR or THR cohort. Conclusions. These findings suggest that although preoperative widespread pressure pain sensitivity is associated with pain severity before and after joint replacement, it is not a predictor of the amount of pain relief that patients gain from joint replacement surgery, independent of preoperative pain severity. Level of Evidence. 2. Approvals. The APEX trials were registered as an International Standardised
Background. To investigate whether the interaction between pre-operative widespread hyperalgesia and radiographic osteoarthritis (OA) was associated with pain severity before and after total hip replacement (THR) and total knee replacement (TKR). Methods. Data were analysed from 232 patients receiving THR and 241 receiving TKR. Pain was assessed pre-operatively and at 12 months post-operatively using the WOMAC Pain Scale. Widespread hyperalgesia was assessed through forearm pressure pain thresholds (PPTs) measured using an algometer. The severity of radiographic OA was evaluated using the Kellgren and Lawrence scheme. Statistical analysis was conducted using linear regression and multilevel models, and adjusted for confounding variables. Results. Pre-operative. In knee patients, there was weak evidence that the effect of PPTs on pain severity was greater in patients with more severe OA compared to patients with less severe OA (Grade 3 OA: ß=0.96 vs Grade 4 OA: ß=4.03). However, in hip patients, the effect of PPTs on pain severity did not differ with the extent of radiographic OA (Grade 3 OA: ß=3.95 vs Grade 4 OA: ß=3.67). Post-operative. Patients undergoing TKR with less severe OA who had lower PPTs (greater widespread hyperalgesia) benefitted less from surgery than patients with higher PPTs (Grade 3 OA: ß=2.28). Conversely, patients undergoing THR with more severe OA who had lower PPTs benefited more from surgery than patients with higher PPTs (Grade 4 OA: ß=−2.92). Conclusion. Central sensitisation may be a determinant of how much patients benefit from joint replacement, but the effect varies by joint and severity of structural joint changes. Level of Evidence. 2. Approvals. The APEX trials were registered as an International Standardised
