Restoring native hip anatomy and biomechanics is important to create a well-functioning total hip arthroplasty (THA). Hip offset and leg length are regarded as the most important biomechanical characteristics. This study investigated their association with clinical outcomes including patient reported outcome measures (PROMs) and functional tests. This prospective cohort study was conducted in 77 patients undergoing primary THA (age=65±11 years). Hip offset and leg length were measured on anteroposterior radiographs of the hip pre- and postoperatively. Participants completed the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) and performed functional tests (i.e. gait, single leg stance, sit-to-stand, block step-up) preoperatively, and 3 and 12 months postoperatively. A wearable motion sensor was used to derive biomechanical parameters. Associations between radiographic and functional outcomes were investigated with the Spearman's rho correlation coefficient. Subgroup comparisons were conducted for patients with more than 15% decreased or increased femoral offset after THA. Differences in postoperative offset and leg length had little impact on clinical outcomes. Femoral offset subgroups demonstrated no significantly different WOMAC function scores. In functional tests, patients with >15% decreased femoral offset after THA demonstrated more sagittal plane motion during block step-up (14.43° versus 10.66°; p=0.04) while patients with >15% increased femoral after THA demonstrated more asymmetry of frontal plane motion during block step-up (34.05% versus 14.18%; p=0.03). To create a well-functioning THA, there seems to be a reasonable safe zone regarding the reconstruction of offset and leg length.
The aim of this study was to determine the outcomes and survivorship of the Triathlon knee replacement at 7 years after surgery. A cohort of 266 patients receiving a Triathlon knee replacement were assessed before surgery and at 3 months, 1 year, 2 years, 3 years, 5 years and 7 years post-operation. Patient-reported outcomes were assessed using the WOMAC, KOOS Knee-Related Quality of Life scale, Satisfaction Scale and questions on kneeling ability and whether they regretted having the operation. Data on survivorship was collected from self-report and medical records. At 7 years after surgery, 32 patients were deceased, and 17 patients were withdrawn. Of the 217 patients remaining in the study, 164 (76%) returned a completed study questionnaire. At 7 years after surgery, 92% of patients reported an improvement in their WOMAC Pain score greater than the minimally clinically important improvement (defined as improvement of ≥9 points from before surgery) and 82% reported this in their WOMAC Function score (defined as improvement of ≥12 points). Knee-related quality of life was good, with a mean score of 66.8 (SD 26.0) (0–100 scale, worst to best). A high percentage of patients (89%) were somewhat or very satisfied with their outcome at 7 years. Survivorship with revision as the endpoint was 96.4% (95% CI 93.2–98.1%) at 7 years post-operation. Five percent of patients regretted having their operation and 68% reported much difficulty or an inability to kneel. In conclusion, this study observed good long-term patient outcomes and survivorship of the Triathlon knee replacement.
To aid recovery, rehabilitation is an important adjunct to surgery. Acknowledging the MRC framework for complex interventions we assessed the evidence-base for components of comprehensive rehabilitation in total hip (THR) and total knee replacement (TKR) pathways. We conducted systematic reviews and meta-analyses of randomised controlled trials (RCT) of pre-surgical exercise and education, occupational therapy and post-operative physiotherapy. In feasibility RCTs we explored acceptability of pain self-management and occupational therapy before THR, and physiotherapy after TKR. We searched trial registers for ongoing RCTs.Background
Methods
Inpatient physiotherapy is routinely provided after total knee replacement (TKR) surgery to enhance recovery prior to discharge. However, the provision of outpatient physiotherapy is variable in the UK, and the longer-term benefits of outpatient physiotherapy are unclear. This study aimed to evaluate the feasibility of conducting a randomised controlled trial (RCT) to assess the effectiveness and cost-effectiveness of group-based outpatient physiotherapy after TKR. Patients listed for primary TKR were recruited prior to surgery. Patients who decided not to participate were asked about their reasons for non-participation. Patients were randomised to attend a newly developed post-operative physiotherapy class plus usual care or usual care alone. Patients allocated to the intervention group were invited to attend a weekly one-hour physiotherapy class, starting at 6 weeks after surgery and running over 6 consecutive weeks. The group classes were run by two physiotherapists within an outpatient gym, and involved task-orientated and individualised exercises. Classes ran on a rolling system, allowing new patients to join each week. Participants completed an evaluation questionnaire after the final class. Outcomes assessment was by questionnaire prior to surgery and 2 weeks, 3 months and 6 months after surgery. Outcomes related to function, pain, balance, self-efficacy, participation, quality of life and resource use.Background
Methods
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. 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.Background
Patients and methods
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. 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.Background
Methods
There is a paucity of long term data concerning the pre and postoperative patient reported function of total knee replacement. The aim of this study was to determine the mortality, implant survivorship, patient reported function and satisfaction in a cohort of 114 patients, from a single centre, who received a Kinemax total knee replacement more than 15 years ago. Patients completed a questionnaire incorporating validated disease- and joint-specific scores, patient satisfaction and overall health preoperatively, at 3 months, 1 year, 2 years and a minimum of 15 years following surgery. NHS National Strategic Tracing Service, hospital and primary care records were used to establish mortality and for implant survivorship in deceased patients.Background
Methods
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). 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.Background
Methods
While many studies have investigated long-term outcomes after lower limb arthroplasty, rather less is known about the trajectory of short-term outcomes in the first post-operative year. It is difficult for a surgeon to know when, in terms of disease severity, it is best to operate, or to make an accurate prediction of the patient pattern of post-operative recovery. We explored the trajectory of change in pain and function following primary hip and knee arthroplasty and the influence of pre-operative self-reported symptoms on post-operative improvements. A prospective UK cohort study of 164 patients undergoing primary hip (n=80) or knee (n=84) arthroplasty. WOMAC pain and function measures were collected pre-operatively and at 3 and 12 months post-operatively. Hip and knee arthroplasties were analysed separately, and patients were split into two groups: those with high or low symptoms pre-operatively. Multilevel regressions were used for each outcome (pain and function), and the trajectory of change (0–3 months and 3–12 months) charted. The study was approved by Southwest 4 Research Ethics Committee (09/H0102/72) and all patients provided informed, written consent. The authors have no competing interests to disclose.Background
Methods
There is limited information about the extent to which the association between pre-operative and chronic post-operative pain is mediated via pain-on-movement or pain-at-rest. We explored these associations in patients undergoing total hip (THR) and total knee (TKR) replacement. 322 and 316 patients receiving THR and TKR respectively were recruited into in a single centre UK cohort (APEX) study. Pre-operative, acute post-operative and 12-month pain severity was measured using self-reported pain instruments. The association between pre-operative / acute pain and chronic post-operative pain was investigated using structural equation modelling (SEM).Objective
Methods
Total hip replacement (THR) and total knee replacement (TKR) are usually effective at relieving pain; however, 7–23% of patients experience chronic post-surgical pain. These trials aimed to investigate the effect of local anaesthetic wound infiltration on pain severity at 12 months after primary THR or TKR for osteoarthritis. Between November 2009 and February 2012, 322 patients listed for THR and 316 listed for TKR were recruited into a single-centre double-blind randomised controlled trial. Participants were randomly assigned (1:1) to receive local anaesthetic infiltration and standard care or standard care alone. Participants and outcomes assessors were masked to group allocation. The primary outcome was pain severity on the WOMAC Pain scale at 12 months post-surgery. Analyses were conducted using intention-to-treat and per-protocol approaches. Ethics approval was obtained from Southampton and South West Hampshire Research Ethics Committee.Background
Methods
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. 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.Background
Methods
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.
Around 20% of patients who have total knee replacement find that they experience long-term pain afterwards. There is a pressing need for better treatment and management for patients who have this kind of pain but there is little evidence about how to improve care. To address this gap we are developing a complex intervention comprising a clinic to assess potential causes of a patient's long-term pain after knee replacement and onwards referral to appropriate, existing services. The Medical Research Council recommends that development of complex interventions include several stages of development and refinement and involvement of stakeholders. This study comprises the penultimate stage in the comprehensive development of this intervention. Earlier stages included a survey of current practice, focus groups with healthcare professionals, a systematic review of the literature and expert deliberation. Healthcare professionals from diverse clinical backgrounds with experience of caring for patients with long-term pain after knee replacement were sent a study information pack. Professionals who wished to participate were asked to return their signed consent form and completed study questionnaire to the research team. Participants rated the appropriateness of different aspects of the assessment process and care pathway from 1–9 (not appropriate to very appropriate). Data were collated and a document prepared, consisting of anonymised mean appropriateness ratings and summaries of free-text comments. This document was then discussed in 4 facilitated meetings with healthcare professional held at the future trial centres. A summary report and revised care pathway was then prepared and sent to participants for further comments. 28 professionals completed the questionnaire and/or attended a meeting. Participants included surgeons, physiotherapists, nurses, pain specialists and rheumatologists. Mean appropriateness scores ranged from 6.9 to 8.4. Taking a score of 7–9 as agreement, consensus was achieved that the assessment should be performed at 3 months post-operative by an extended scope practitioner/nurse, treatment be guided by a standardised assessment of pain, and treatment individualised. There was also agreement that referrals in the care pathway to surgical review, GP and pain clinics were appropriate. Nurse-led/self-monitoring was rated lower (6.9) because of considerations about the need to ensure that patients receive appropriate support, follow-up and referral to other services. This work demonstrates the research methods that can be used to refine the design of a complex intervention. The process and findings enable refinement of an intervention for patients with long-term pain after knee replacement. The next stage of intervention development will assess the acceptability and reliability of the assessment process, and the usability of the intervention's standard operating procedures. The intervention will then be evaluated by a larger research team in a multi-centre randomised controlled trial, starting in late 2016.
Patients report similar or better pain and function before revision hip arthroplasty than before primary arthroplasty but poorer outcomes after revision surgery. The trajectory of post-operative recovery during the first 12 months and any differences by type of surgery have received little attention. We explored the trajectories of change in pain and function after revision hip arthroplasty to 12-months post-operatively and compared them with those observed after primary hip arthroplasty. We conducted a single-centre UK cohort study of patients undergoing primary (n = 80) or revision (n = 43) hip arthroplasty. WOMAC pain and function scores and 20-metres walking time were collected pre-operatively, at 3 and 12-months post-operatively. Multilevel regression models were used to chart and compare the trajectories of post-operative change (0–3 months and 3–12 months) between the types of surgery. Patients undergoing primary arthroplasty had a total hip replacement (n=74) or hip resurfacing (n=6). Osteoarthritis was the indication for surgery in 92% of primary cases. Patients undergoing revision arthroplasty had revision of a total hip arthroplasty (n=37), hemiarthroplasty (n=2) or hip resurfacing (n=4). The most common indication for revision arthroplasty was aseptic loosening (n=29); the remaining indications were pain (n=4), aseptic lymphocyte-dominated vasculitis-associated lesion (n=4) or other reasons (n=6). Primary (87%) and revision arthroplasties (98%) were mostly commonly performed via a posterior surgical approach. The improvements in pain and function following revision arthroplasty occurred within the first 3-months following operation (WOMAC-pain, p<0.0001; WOMAC-function, p<0.0001; timed 20-metres walk, p<0.0001) with no evidence of further change beyond this initial period (p>0.05) While the pattern of recovery after revision arthroplasty was similar to that observed after primary arthroplasty, improvements in the first 3-months were smaller after revision compared to primary arthroplasty (p<0.0001). Patients listed for revision surgery reported lower pre-operative pain levels (p=0.03) but similar post-operative levels (p=0.268) compared to those undergoing primary surgery. At 12-months post-operation patients who underwent a revision arthroplasty had not reached the same level of function achieved by those who underwent primary arthroplasty (WOMAC-function p=0.015; Time walk p=0.004). Patients undergoing revision hip arthroplasty should be informed that the majority of their improvement will occur in the first 3-months following surgery and that the expected improvement will be less marked than that experienced following primary surgery. More research is now required to 1.) identify whether specific in-patient and post-discharge rehabilitation tailored towards patients undergoing revision arthroplasty would improve or achieve equivalent outcomes to primary surgery and 2.) whether patients who are achieving limited improvements at 3-months post-operative would benefit from more intensive rehabilitation. This will become all the more important with the increasing volume of revision surgery and the high expectations of patients who aspire to a disease-free and active life.
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.
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.
