An important subset of patients is dissatisfied after total joint arthroplasty (TJA) due to residual functional impairment. This study investigated the assessment of objectively measured step-up performance following TJA, to identify patients with poor functional improvement after surgery, and to predict residual functional impairment during early postoperative rehabilitation. Secondary, longitudinal changes of block step-up (BS) transfers were compared with functional changes of subjective patient reported outcome measures (PROMs) following TJA. Patients with end stage hip or knee osteoarthritis (n = 76, m/f = 44/32; mean age = 64.4 standard deviation 9.4 years) were measured preoperatively and 3 and 12 months postoperatively. PROMs were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function subscore. BS transfers were assessed by wearable-derived measures of time. In our cohort, subgroups were formed based on either 1) WOMAC function score or 2) BS performance, isolating the worst performing quartile (impaired) of each measure from the better performing others (non-impaired). Subgroup comparisons were performed with the Man-Whitney-U test and Wilcoxon Signed rank test resp. Responsiveness was calculated by the effect size, correlations with Pearson's correlation coefficient. A regression analysis was conducted to investigate predictors of poor functional outcome.Introduction and Objective
Materials and Methods
Patients with knee prosthetic joint infection (PJI) frequently receive one- or two-stage revision. To explore the feasibility of a randomised controlled trial (RCT) comparing methods, we analysed a UK registry, interviewed patients and surgeons, systematically reviewed literature, held a consensus meeting, and assessed progress of an RCT in hip PJI. In 2014, in England and Wales, knee PJI was treated with one- or two-stage procedures in 19% and 71% of patients respectively. Between 2007 and 2014, use of one-stage procedures doubled and, in major centres, up to 42% of treatments were one-stage. We conducted in-depth interviews with 16 patients with knee PJI and 11 surgeons performing one- or two-stage revision. Patients considered randomisation acceptable with appropriate counselling and, depending on infecting organisms and health status, surgeons would randomise treatments. In meta-analysis, two-year re-infection rates in 10 one-stage series (423 patients) and 108 two-stage series (5,129 patients) were 7.6% (95%CI 3.4,13.1) and 8.8% (7.2,10.6) respectively. In a series of patients with knee PJI, surgeons from 2 major centres considered 6/15 patients eligible for either treatment, with 4 more potentially eligible after treatment of soft tissue infection. In an ongoing RCT of surgical treatment of hip PJI, 116 patients have been randomised at 14 centres in 3 years. Randomising patients with PJI is feasible but, as knee PJI is uncommon, a multicentre RCT would be required. Based on WOMAC score outcome and appropriate assumptions on eligibility and acceptability, 170 patients would need to be randomised over 4 years at 14 major centres.
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.
Periprosthetic joint infections (PJIs) are uncommon but are devastating complications of total knee replacement (TKR). We analysed the risk factors of revision for PJI following primary TKR and their association with PJI at different post-operative periods. Primary TKRs and subsequent revision surgeries performed for PJI from 2003–2014 were identified from the National Joint Registry (NJR). Multilevel piece-wise exponential non-proportional hazards models were used to estimate the effect of the investigated factors at different post-operative periods. Patient, perioperative and healthcare system characteristics were investigated and data from the Hospital Episode Statistics for England were linked to obtain information on specific comorbidities. The index TKRs consisted of 679,010 primaries with 3,659 subsequently revised for PJI, 7% within 3 months, 6% between 3–6months, 17% between 6–12months, 27% between 1–2years and 43% ≥2 years from the index procedure. Risk factors for revision for PJI included male sex, high BMI, high ASA grade and young age. Patients with chronic pulmonary disease, diabetes and liver disease had higher risk of revision for PJI, as had patients who had a primary TKR for an indication of trauma or inflammatory arthropathy. Surgical procedure, fixation method, constraint and bearing type influenced the risk of revision for PJI. Their effects were period-specific. No or small associations were found with the operating surgeon grade, surgical volume and hospital surgical volume. These findings from the world's largest joint replacement registry show a more complex picture than the meta-analyses published to date with specific time-dependent effects for the identified risk factors.
Administration of perioperative antibiotic prophylaxis (AP) reduces the risk of prosthetic joint infection (PJI) following primary total hip (THA) and knee (TKA) arthroplasty. The optimal type of antibiotic used, and duration of prophylaxis are subject to debate. We compared the risk of revision surgery for PJI in the first year following THA and TKA by AP regimen. A national survey collecting information on hospital-level AP regimen policy was conducted across the Netherlands and linked to data from the LROI arthroplasty registry for 2011–2015. PJI status was defined using the surgical indication reported at revision by surgeons in the registry form. Restricted cubic splines Poisson model adjusted for hospital clustering were used to conduct the comparisons on 130,712 THAs and 111,467 TKAs performed across 99 institutions. These included 399 THAs and 303 TKAs revised for an indication of PJI. Multiple shot of Cefazolin (MCZ), of cefuroxime (MCX) and single shot of Cefazolin (SCZ) were respectively administrated to 87%, 4% and 9% of patients. For THA, the rates of revision for PJI were respectively 31/10,000 person-years 95%CI[28, 35], 39[25, 59] and 23[15, 34] in the groups which received MCZ, MCX and SCZ; respectively, the rates for TKA were 27[24, 31], 40[24, 62] and 24[16, 36]. No evidence of difference between AP regimens was found in the unadjusted and adjusted model (age, gender, BMI and ASA grade). Further work is advocated to confirm whether there is an association between AP regimen collected at patient-level and the risk of subsequent revision for PJI.
Prosthetic joint infection (PJI) is an uncommon but serious complication of hip replacement. A recent systematic review of patient risk factors for PJI identified male gender, smoking status, increasing BMI, steroid use, previous joint surgery and comorbidities of diabetes, rheumatoid arthritis and depression as risk factors for developing PJI. Limitations of the current literature include the short term follow up of most published studies. We investigated the role of patient, surgical and healthcare factors on the risk of revision of a primary hip replacement for PJI at different time-points in the post-operative follow-up. It is important that those risk factors are identified so that patients can be appropriately counselled according to their individual risk profile prior to surgery and modifiable factors can be addressed to reduce the risk of PJI at an individual and healthcare system level. Primary hip replacements and subsequent revision procedures performed for PJI from 2003–2014 were identified from the National Joint Registry (NJR). Patient (age, gender, ASA grade, BMI), perioperative (surgical indication, type of anaesthesia, thromboprophylaxis regime, surgical approach, hip replacement and bearing surface and use of femoral or acetabular bone graft) and healthcare system characteristics (surgeon grade, surgical volume) were linked with data from Hospital Episode Statistics to obtain information on specific ethnicity and comorbidities (derived from the Charlson index). Multilevel piecewise exponential non-proportional hazards models were used to estimate their effects at different post-operative periods (0–3 months, 3–6 months, 6–12 months, 12–24 and >24 months post-operation).Introduction
Materials and Methods
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
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
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. 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.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.
Prosthetic joint infection (PJI) is an uncommon but serious complication of hip and knee replacement. We investigated the rates of revision surgery for the treatment of PJI following primary and revision hip and knee replacement, explored time trends, and estimated the overall surgical burden created by PJI. We analysed the National Joint Registry for England and Wales for revision hip and knee replacements performed for a diagnosis of PJI and their index procedures from 2003–2014. The index hip replacements consisted of 623,253 primary and 63,222 aseptic revision hip replacements with 7,642 revisions subsequently performed for PJI; for knee replacements the figures were 679,010 primary and 33,920 aseptic revision knee replacements with 8,031 revisions subsequently performed for PJI. Cumulative incidence functions, prevalence rates and the burden of PJI in terms of total procedures performed as a result of PJI were calculated. Revision rates for PJI equated to 43 out of every 10,000 primary hip replacements (2,705/623,253), i.e. 0.43%(95%CI 0.42–0.45), subsequently being revised due to PJI. Around 158 out of every 10,000 aseptic revision hip replacements performed were subsequently revised for PJI (997/63,222), i.e. 1.58%(1.48–1.67). For knees, the respective rates were 0.54%(0.52–0.56) for primary replacements, i.e. 54 out of every 10,000 primary replacements performed (3,659/679,010) and 2.11%(1.96–2.23) for aseptic revision replacements, i.e. 211 out of every 10,000 aseptic revision replacements performed (717/33,920). Between 2005 and 2013, the risk of revision for PJI in the 3 months following primary hip replacement rose by 2.29 fold (1.28–4.08) and after aseptic revision by 3.00 fold (1.06–8.51); for knees, it rose by 2.46 fold (1.15–5.25) after primary replacement and 7.47 fold (1.00–56.12) after aseptic revision. The rates of revision for PJI performed at any time beyond 3 months from the index surgery remained stable or decreased over time. From a patient perspective, after accounting for the competing risk of revision for an aseptic indication and death, the 10-year cumulative incidence of revision hip replacement for PJI was 0.62%(95%CI 0.59–0.65) following primary and 2.25%(2.08–2.43) following aseptic revision; for knees, the figures were 0.75%(0.72–0.78) following primary replacement and 3.13%(2.81–3.49) following aseptic revision. At a health service level, the absolute number of procedures performed as a consequence of hip PJI increased from 387 in 2005 to 1,013 in 2014, i.e. a relative increase of 2.6 fold. While 70% of those revisions were two-stage, the use of single stage revision increased from 17.6% in 2005 to 38.5% in 2014. For knees, the burden of PJI increased by 2.8 fold between 2005 and 2014. Overall, 74% of revisions were two-stage with an increase in use of single stage from 10.0% in 2005 to 29.0% in 2014. Although the risk of revision due to PJI following hip or knee replacement is low, it is rising. Given the burden and costs associated with performing revision joint replacement for prosthetic joint infection and the predicted increased incidence of both primary and revision hip replacement, this has substantial implications for service delivery.
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.
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.
