Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM:EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI.

A panel of 21 expert stakeholders collaborated to develop best practice guidelines based on evidence from INFORM \[1\]. An expert consensus process was used to refine guidelines using RAND/UCLA criteria. The guidelines were then implemented over a 12-month period through a Learning Collaborative of 24 healthcare professionals from 12 orthopaedic centres in England. Qualitative interviews were conducted with 17 members of the collaborative and findings used to inform the development of an implementation support toolkit. Patient and public involvement contextualised the implementation of the guidelines. The study is registered with the ISCRTN (34710385).

The INFORM guidelines, structured around the stages of PJI management, were largely supported by surgeons, although barriers included limited awareness among non-surgical team members, lack of job planning for multidisciplinary teams, and challenges in ensuring timely referrals from primary care. Psychological support for patients was identified as a critical gap. Advanced Nurse Practitioners and multidisciplinary team (MDT) coordinators were seen as potential bridges to address these knowledge gaps. The guidelines were also viewed as a useful tool for service development.

This study presents the first evidence-based guidelines for hip PJI management, offering a comprehensive approach to prevention, treatment, and postoperative care. Effective implementation is crucial, involving wider dissemination amongst primary and community care, as well as non-specialist treatment centres. Further resources are needed to ensure job planning for MDTs and psychological support for patients. Overall, this study lays the foundation for improved PJI management, benefiting patients and healthcare systems.

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Studies have shown that 10–30% patients do not achieve optimal function outcomes after total hip replacement (THR). High quality randomised controlled trials (RCTs) evaluating the clinical and cost-effectiveness of techniques to improve functional outcomes after THR are lacking. We performed this study to evaluate the feasibility of a RCT comparing patient-reported functional outcomes after hybrid or fully cemented THR (ISRCTN11097021).

Patients were recruited from two centres and randomised to receive either a fully cemented or hybrid THR. Data collection included Patient Reported Outcome Measures (PROMs), non-serious adverse events of special interest (AESI), serious adverse device effects (SADE) and NHS resource use. Qualitative interviews were undertaken to understand a) patient experiences of study processes and their reasons for taking part or not, and b) to understand surgeons’ perceptions of the study, factors affecting willingness to participate, and barriers to implementation of the future RCT findings.

The target of 40 patients were successfully recruited for the feasibility RCT; the ratio of successful recruitment to eligible patients was 0.61 across both sites. Treatment crossovers occurred in four patients, all related to bone quality. Four patients were withdrawn due to not undergoing surgery within the study window because of the pandemic. Follow-up was 100% and PROMs were completed by all patients at all time points. The feasibility of conducting a within-trial cost-utility analysis was demonstrated. Interviews were conducted with 27 patients and 16 surgeons. Patients and surgeons generally found the study procedures acceptable and workable. Some declined participation because they did not want treatment allocated at random, or because blinding was off-putting. Surgeons’ perceptions of equipoise varied, and implementation of findings from the future RCT would need to recognise the ‘craft’ nature of surgery and the issue of training.

We conclude that a full RCT with economic analysis will be both feasible and practicable, although mechanisms to safely implement potential changes to practice because of RCT findings may need consideration by the wider arthroplasty community.

Aims

Periprosthetic hip-joint infection is a multifaceted and highly detrimental outcome for patients and clinicians. The incidence of prosthetic joint infection reported within two years of primary hip arthroplasty ranges from 0.8% to 2.1%. Costs of treatment are over five-times greater in people with periprosthetic hip joint infection than in those with no infection. Currently, there are no national evidence-based guidelines for treatment and management of this condition to guide clinical practice or to inform clinical study design. The aim of this study is to develop guidelines based on evidence from the six-year INFection and ORthopaedic Management (INFORM) research programme.

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.

Background

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.

Background

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.

Background

Total knee replacement (TKR) is an effective operation for many patients, however approximately 20% of patients experience chronic pain and functional limitations in the months and years following their TKR. If modifiable pre-operative risk factors could be identified, this would allow patients to be targeted with individualised care to optimise these factors prior to surgery and potentially improve outcomes. Psychosocial factors have also been found to be important in predicting outcomes in the first 12 months after TKR, however their impact on long-term outcomes is unknown. This study aimed to identify pre-operative psychosocial predictors of patient-reported and clinician-assessed outcomes at one year and five years after primary TKR.

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.

Background

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.

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).

Background

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.

Objective

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.

Background

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.

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.

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.

Total knee arthroplasty (TKA) remains a safe and effective intervention for the treatment of arthritis of the knee. It does, however, carry risks including death. Studies have compared the incidence of death following TKA to standardised mortality ratios of matched populations. This often suggests that TKA is protective to health in the immediate post operative phase, attributed to the lower incidence of co-morbidities in patients undergoing surgery.

In an attempt to remove this “well patient effect”, we compared the incidence of death in the first 30 and 90 days following primary TKA to that of a comparable population added to a waiting list for the same procedure.

All primary TKAs undertaken, and all patients added to a waiting list for the same procedure, in a single unit between 2000 and 2007 were recorded. Death rates at 30 and 90 days were compared in each group.

The 30 and 90 day mortality following primary TKA were 0.295% and 0.565% respectively, compared to a 30 and 90 day mortality of 0.055% and 0.316% seen in a population of patients awaiting operation. When stratified for age, surgery conferred an excess surgical mortality in all age groups over the age of 60. Factors associated with an increased mortality following operation include male gender and increasing age.

Previous studies have suggested that TKA is associated with a decreased risk of death. This study demonstrates an increased risk of death associated with surgery in comparison to a similar population deemed fit enough to undergo operation. Primary TKA carries an excess surgical mortality of 0.24% at 30 days and 0.25% at 90 days, a 5.36 and 1.79 times greater risk of death when compared to patients awaiting the same procedure.

This information will greatly assist orthopaedic surgeons when counselling patients as to the risks of surgery.

Introduction: Although the primary aim of Total Knee Replacement (TKR) is to relieve chronic joint pain, 10–20% of patients experience unexplained chronic pain after surgery. One possible cause of this pain is central sensitisation. Prolonged exposure to a noxious input can lead the central nervous system to become sensitised to pain (central sensitisation), which can become self-sustaining and persist after the removal of the noxious stimuli i.e after TKR. The aim of this study was to determine if knee osteoarthritis (OA) patients awaiting TKR have evidence of sensory perception abnormalities, by comparing detection and pain thresholds from OA patients to those of age- and gender-matched healthy participants.

Patients and Methods: Quantitative Sensory Testing (QST) was performed on 107 knee OA patients on the waiting list for primary TKR and 50 age- and gender-matched healthy participants without knee pain or TKR. QST assesses somatosensory function through measuring participant responses to external stimuli of controlled intensity. QST was performed on both knees and the pain-free forearm of all participants. Von Frey filaments were used to measure touch detection thresholds, a digital Algometer to measure pressure pain thresholds, and the MSA Thermotest to measure detection and pain thresholds to hot and cold. Significant differences in the median threshold values between knee OA patients and healthy participants were tested for using Mann-Whitney U tests.

Results: Detection thresholds: OA patients had significantly higher detection thresholds for hot and cold (both p< 0.05) in the index knee (but not at other sites) compared to healthy participants. Touch detection thresholds were significantly higher at all body sites in OA patients compared to healthy participants (all p< 0.001).

Pain thresholds: Pressure pain thresholds were significantly lower in OA patients at all body sites (all p< 0.001) but there were no significant differences in hot or cold pain thresholds between OA patients and healthy participants at any body site (all p> 0.05).

Discussion: This study showed that knee OA patients have modality-specific sensory and pain perception abnormalities. These included thermal hypoesthesia (reduced sensitivity) in the index knee and tactile hypoesthesia at all body sites tested, alongside hyperalgesia (increased pain sensitivity) to pressure pain at all body sites. Future research aims to determine if these sensory perception abnormalities are predictive of chronic pain after TKR.

Introduction: The principal aim of total knee replacement (TKR) surgery is to relieve chronic knee pain. However, following recuperation from surgery, 10–30% of patients report chronic pain in the replaced joint. There has been little research investigating the impact of this continuing pain on patients’ lives or exploring the way in which individuals adjust to this pain. Therefore, the aim of this study is to explore, from their own perspectives, patients’ experiences of chronic pain following this end-stage treatment of TKR.

Participants and Methods: Participants were twenty-eight patients who had undergone a TKR with the National Health Service at Bristol, Southwest UK, and who reported chronic pain in the replaced knee joint at least one year post-operatively. Purposive sampling was used in order to recruit participants both of a range of ages and with moderate to severe chronic pain. In-depth, semi-structured interviews were conducted with participants. Interviews explored individuals’ perceptions of the identity of their condition, its cause, duration and consequences and whether they had any control over it. Data was analysed using thematic analysis.

Results: Analysis revealed that, while all participants experienced chronic pain which necessitated the use of pain relief medication, there was great variation among individuals in terms of their adjustment to their condition: while some were well adjusted and accepting of their pain, for others the pain constituted a source of ongoing distress.

Regardless of their expectations concerning level of pain following TKR, those participants who perceived an improvement in pain as a result of their TKR were less likely to expect a cure for their residual pain and were either very well or reasonably well adjusted to the pain. Nevertheless, those who had moderate expectations of outcome were more likely to perceive an improvement than those with high expectations. Those individuals who reported having held high expectations of TKR outcome and subsequently experienced increased pain were likely to experience distress in relation to their pain; those who also felt that a cure for their current pain may be possible experienced particularly high levels of distress.

Discussion: The findings show the significance of cognitions, beliefs and expectations to individuals’ adjustment to chronic pain following TKR. They highlight a group of patients for whom adjustment may be problematic, which could indicate the need for assessment and intervention. There could be potential for surgeons to influence their patients’ adjustment positively by attempting to instil realistic expectations both prior to surgery and when chronic pain is experienced after recovery from TKR.

Total knee arthroplasty represents one of the greatest advances in modern orthopaedic surgery and remains one of the safest and most effective interventions for the treatment of crippling arthritis of the knee. It does, however, carry significant risk including death. Conventional studies have compared the incidence of death following knee arthroplasty to standardised mortality ratios of age and sex matched populations. This often raises aberrant results suggesting that knee arthroplasty is protective to health in the immediate post operative phase, attributed to the observation that patients undergoing surgery suffer fewer co morbidities than the population in general.

In an attempt to remove this “well patient effect”, we compared the incidence of death in the first 30 and 90 days following primary total knee arthroplasty to the incidence of death in a comparable population added to a waiting list for the same procedure.

All primary total knee arthroplasties undertaken, and all patients added to a waiting list for the same procedure, in a single unit between 2000 and 2007 were recorded. Death rates at 30 and 90 days of those on the waiting list were compared to death rates after surgery.

The 30 and 90 day mortality following primary total knee arthroplasty were 0.295% and 0.565% respectively. This compares to a 30 and 90 day mortality of 0.055% and 0.316% seen in a population of patients awaiting operation. When stratified for age, surgery conferred an excess surgical mortality in all age groups over the age of 60. Factors associated with an increased mortality following operation include male gender and increasing age.

Previous studies, where incidence of death is compared to standardised mortality ratios, have erroneously suggested that arthroplasty is associated with a decreased risk of death. This study demonstrates an increased risk of death associated with surgery in comparison to a similar population deemed fit enough to undergo operation. Primary total knee arthroplasty carries an excess surgical mortality of 0.24% at 30 days and 0.25% at 90 days, a 5.36 and 1.79 times greater risk of death respectively when compared to patients awaiting the same procedure.

This information will greatly assist orthopaedic surgeons when counselling patients as to the risks of surgery.

This editorial considers the shortcomings of assessing outcome after joint replacement only by the survival of the implant.

Introduction: Patient satisfaction with the outcome of elective surgery is increasingly used as a measure of the patient’s perception of the success of an operation. Satisfaction is an individualistic complex of factors and measuring satisfaction can add another valuable dimension to outcomes assessment after arthroplasty. The aim of this study was to explore patient satisfaction after lower limb arthroplasty.

Patients and Methods: All patients who had a primary joint replacement at the Avon Orthopaedic Centre over a 3-year period were invited to participate in the study. Participants completed a questionnaire which consisted of the WOMAC, the Joint-Related Quality of Life Scale from the KOOS/HOOS, SF-12 and a validated satisfaction scale. The satisfaction questionnaire measures patient satisfaction with four domains of outcome: overall outcome, pain relief, ability to perform ADLs and ability to participate in leisure activites. Responses are on a 4-point Likert scale which ranges from very satisfied to very dissatisfied. A global satisfaction score was calculated from these responses and then transformed onto a 0–100 scale (100 being best).

Results: Completed questionnaires were received from 2085/3125 patients (67% response rate). 911 respondents had a THR, 866 had a TKR, 157 had a hip resurfacing, 100 had a UKR and 51 had a patellar resurfacing. The mean age of respondents was 70 years and 58% were female. The mean length of follow-up was 28 months.

The median satisfaction score was 100 (interquartile range 75–100). However, within the individual outcome domains dissatisfaction rates were: 9% for pain; 12% for overall outcome; 14% for ADLs; and 17% for leisure activities. To explore differences in satisfaction with age, patients were divided into 3 age groups: < 60 years, 60–80 years and > 80 years. The respective rates of dissatisfaction among the age groups were 13%, 11% and 14%, which were not significantly different (p=0.33). In an analysis of gender and satisfaction, significantly more females were dissatisfied than men (14% vs 10%, p=0.01). When pain, function, quality of life, mental health and physical health were compared between patients who were satisfied (n=1834) and dissatisfied (n=251) with their overall outcome, all outcomes were significantly worse in the dis-satisfied patient group (p< 0.001 for all outcomes).

Discussion: Although the median satisfaction score in this study was 100, there was a group of patients who were not satisfied with their outcome. As well as having worse joint pain and function, dissatisfied patients also have significantly worse quality of life, physical health and mental health compared to satisfied patients. In conclusion, patient satisfaction is one of the key outcomes that should be strived for after an elective intervention, and these results indicate that joint replacement is failing to fully satisfy a proportion of patients.

The aim of this study was to determine patient-reported outcomes after arthroscopic rotator cuff repair with a new knot-free technique.

A questionnaire was completed by 50 patients who underwent an arthroscopic rotator cuff repair with a knot-free technique. Validated questionnaires included the Oxford Shoulder Score (12–60, good to poor) and SF-36 (0–100, poor to good). Patients also completed a 100mm VAS (0–100, good to poor) to rate the following domains: daytime pain, night-time pain, movement, strength, well-being, ability to do ADLs, participation in sports, ability to do leisure activities and whether they felt their shoulder was back to the way it was before the problem started.

The mean length of follow-up was 15 months (range 7–25 months). The mean age of patients was 62 years (range 36–78) and 70% were male. The mean OSS was 22 (SD 10). Mean scores for the 8 domains of the SF-36 were: 74 for physical functioning, 71 for role physical, 66 for bodily pain, 67 for general health, 57 for vitality, 82 for social functioning, 85 for role emotional and 81 for mental health. The mean VAS for the 9 outcome domains were as follows: 16 for night-time pain and daytime pain, 19 for movement, 21 for ability to do ADLs, 22 for well-being, 23 for whether the shoulder was back to the way it was, 28 for ability to do leisure activities, 29 for strength and 33 for ability to participate in sports.

In conclusion, patients reported excellent post-operative OSS with the knot-free technique. The SF-36 revealed that patients had high social and emotional functioning and good physical outcomes were reported on the VAS for pain, ADLs and movement. However, going back to an expected level of sport is not always achievable.

Study Design: This is a retrospective study evaluating the use of BoneSave (Stryker, UK) in posterolateral inter-transverse spinal fusion.

Objectives. To evaluate the clinical outcomes and fusion success rates associated with the use of BoneSave in posterolateral spinal fusion.

Summary of Background Data: Achieving spinal fusion is the guiding principle behind surgical treatment for a range of pathologies of the spine. The use of a substantial amount of bonegraft is often required and autograft, commonly harvested from the iliac crest, represents the gold standard. Morbidities associated with graft harvest and a limited supply of graft material have led to the development of alternatives. BoneSave, a porous tricalcium phosphate-hydroxyapatite ceramic, is one such alternative which has been employed in spinal fusion over the past few years. Despite this the outcomes associated with its use lack research.

Methods: Clinical data was collected retrospectively from the case notes of all patients who underwent posterolateral inter-transverse spinal fusion at any level, involving the application of BoneSave, between June 2003 and January 2005 at Frenchay hospital, Bristol, UK. A postal questionnaire was used to collect the latest follow-up information, with an average follow-up of 46 months. Validated outcome instruments employed included the Short Form 36 and Oswestry Low Back Pain Disability Index. In addition visual analogue scales for both back and leg pain, Patient Global Impression of Change data, work status, persisting symptoms, and patient satisfaction data was collected. Radiological evaluation of fusion was carried out from the most recent spinal radiographs available for each patient.

Results: There were 45 patients in the study group. Qualitative post-operative data was available in 96% and response rate to the follow-up questionnaire was 68.4%. Radiographical evaluation was possible in 67%. Significant post-operative improvements were seen across all outcome measures in the large majority of cases. Successful fusion was achieved in 56.7% of cases.

Conclusion: The clinical outcomes associated with the use of BoneSave are comparable to those available in the literature for more conventional techniques of spinal fusion. The fusion rate was not significantly lower than achieved with other techniques.

Introduction: Joint replacement has a low mortality rate, few adverse occurrences, excellent survivorship and is considered a cost-effective intervention to reduce disability in the community. However, the assessment of complications and survivorship fail to measure the success of joint replacement in achieving pain relief and restoration of functional ability. The aim of this large cross-sectional postal survey was to provide information on the prevalence of pain, disability, poor quality of life and patient dissatisfaction at 1–3 years after a range of lower limb orthopaedic surgeries in the UK.

Patient and Methods: A questionnaire was posted to all 3,125 consecutive alive patients who underwent a primary THR, hip resurfacing, TKR, UKR or patellar resurfacing at the Avon Orthopaedic Centre between January 2004 – April 2006. The questionnaire included the WOMAC, HOOS/KOOS quality of life scale and a validated satisfaction scale. All questionnaires are scored on a 0–100 scale (worst-best) and a poor outcome was defined as a score of ≤ 50 on the outcome measure.

Results: Completed questionnaires were received from 2,085 patients (response rate of 67%). Patients had a mean age of 67 years and 42% were male. The mean length of follow-up was 28 months (range 14–44 months). 911 patients had a THR, 157 patients had a hip resurfacing, 866 patients had a TKR, 100 patients had a UKR and 51 patients had a patellar resurfacing.

Pain: the prevalence of poor outcomes were 6% of patients with a THR, 4% with a hip resurfacing, 12% with a TKR, 9% with a UKR and 31% with a patellar resurfacing.

Conclusion: This survey has provided descriptive data on the prevalence of patient-reported levels of pain, disability, poor joint-related quality of life and dissatisfaction after lower limb arthroplasty. It is important that patient-reported outcomes after joint replacement are rigorously assessed in order to provide information on which patients do poorly after surgery, with the aim of targeting these patients with an intervention to improve their outcome.

North Bristol Trust Small Grants Scheme provided funding for the consumables for this study.

Background: Because of the changing demographics of the population and improvements in prosthesis design and surgical technique, ever-increasing numbers of younger patients are undergoing joint replacement. Younger patients often receive hip resurfacing rather than conventional THR because of the preservation of bone stock and the lower risk of dislocation. However, pain relief and restoration of function for younger patients is particularly important to continue with a normal, active life. Yet there is little existing research to establish if hip resurfacing results in better patient-reported outcomes than conventional total hip replacement (THR). Therefore, the aim of this study was to compare patient-reported outcomes after hip resurfacing and THR, after controlling for age, gender, general health and length of follow-up.

Methods: A postal survey was sent to all patients who had a hip resurfacing or primary THR between April 2004 - April 2006 at the Avon Orthopaedic Centre. To assess hip pain and function, quality of life, general health and satisfaction with the outcome of surgery, the questionnaire included the WOMAC, HOOS Quality of Life Scale, SF-12 and a validated satisfaction scale. The continuous outcome scores were compared for those who had a THR and those who had hip resurfacing, after adjusting for age, sex, general health and length of follow-up, using Analysis of Variance.

Results: Completed questionnaires were received from 911 THR patients and 157 hip resurfacing patients (response rate of 68% and 71%). Hip resurfacing patients had a mean age of 52 years and 71% were male. THR patients had a mean age of 68 years and 37% were male. After controlling for the effects of age, gender, general health and follow-up length, there was no significant difference in pain (p=0.70), function (0.85), hip-related quality of life (p=0.66) or satisfaction (0.09) between hip resurfacing patients and THR patients at 1–3 years post-operative.

Conclusions: The findings from this study suggest that hip resurfacing has no short-term clinical advantage over conventional THR. A prospective randomised controlled trial is necessary to further compare patient outcomes after hip resurfacing and THR.

Introduction: Total hip replacement (THR) and total knee replacement (TKR) are widely accepted as effective surgical procedures to alleviate chronic joint pain and improve functional ability. Clinical evidence suggests that joint replacement results in excellent outcomes. Traditionally, reporting of outcomes has been focused on implant survivorship and surgeon based assessment of objective outcomes, such as range of motion, knee stability and radiographic results. However, because there is a discrepancy between patient and clinician ratings of health, patient-reported outcome measures have been validated to allow patients to rate their own health, thereby placing them at the centre of outcome assessment. The aim of this study was to compare the mid-term functional outcomes of TKR and THR using validated patient-reported outcome measures.

Methods: A cross-sectional postal audit survey of all consecutive patients who had a primary, unilateral THR or TKR at the Avon Orthopaedic Centre 5–8 years previously was conducted. Participants completed an Oxford hip score (OHS) or Oxford knee score (OKS). The Oxford questionnaires are self-report joint-specific measures that assess functional ability and pain from the patient’s perspective. They consist of 12 questions about pain and physical limitations experienced over the past four weeks because of the hip or knee.

Results: 1112 THR patients and 613 TKR patients returned a completed questionnaire, giving a response rate of 72%. The median OKS of 26 was significantly worse than the median OHS of 19 (p< 0.001). TKR patients experienced a poorer functional outcome than THR patients on all domains assessed by the Oxford questionnaire, independent of age. The percentage of patients reporting moderate-severe pain was two-fold greater for TKR than THR patients (26% vs 13%, respectively).

Conclusion: This survey found that TKR patients report more pain and functional limitations than THR patients at 5–8 years post-operatively, independent of age. The finding that over a quarter of TKR patients reported moderate-severe pain at 5–8 years post-operative indicates that a large proportion of people are undergoing major knee surgery that is failing to achieve its primary aim of pain relief. This raises questions about whether patient selection for TKR is appropriate. To improve patient selection, it may be necessary to have a preoperative screening protocol to identify patient factors predictive of a poor outcome after TKR. Currently, no such protocol exists and this is an area of orthopaedics requiring further research.

Introduction: Although THR can provide excellent pain relief and restore functional ability for most patients, there is a proportion of patients who experience a poor functional outcome after THR. One factor that could contribute to a poor outcome after THR is leg length discrepancy (LLD). Restoration of leg length is important in optimising hip biomechanics and LLD has several consequences for the patient, including back pain and a limp. Assessment of LLD using radiographs is time consuming and labour intensive, and therefore limits large scale studies of LLD. However, patients self-report of perceived LLD may be a useful tool to study LLD on a large scale. Therefore, the aim of this postal audit survey was to determine the prevalence of patient-perceived LLD after primary THR and its impact on mid-term functional outcomes.

Methods: A cross-sectional postal audit survey of all consecutive patients who had a primary, unilateral THR at the Avon Orthopaedic Centre 5–8 years previously was conducted. Several questions about LLD were included on the questionnaire. Firstly, patients were asked if they thought that their legs were the same length. For those who thought their legs were different lengths, they were asked if the difference bothered them, whether the difference in length leg was enough to comment upon, and whether they used a shoe raise. Participants also completed an Oxford hip score (OHS), which is a self-report measure that assesses functional ability and pain after THR, including limping

Results: 1,114 THR patients returned a completed questionnaire, giving a response rate of 73%. 329 patients (30%) reported that they thought their legs were different lengths. The median OHS for patients with a perceived LLD was 22, which was significantly worse than the OHS of 18 for patients who thought their legs were the same length (p< 0.001). Of the 329 patients with a perceived LLD, 161 patients (51%) were bothered by the difference, 65 patients (20%) thought the discrepancy was sufficient to comment upon and 101 patients (31%) used a shoe raise. 31% of patients with LLD limped most or all of the time compared to only 9% of patients without LLD.

Conclusion: In conclusion, this study found that the prevalence of perceived LLD at 5–8 years after THR was 30%. Of the patients with LLD, over 50% were bothered by the LLD and over a third used a shoe raise to equalise leg lengths. Patients with perceived LLD have a significantly poorer self-report functional outcome than those patients without LLD. It is therefore important that patients are informed pre-operatively of the high risk of LLD after THR and the associated negative impact this may have on their outcome.

Introduction: Venous thromboembolism is a major cause of morbidity and mortality in hospitalised patients and patients undergoing major orthopaedic surgery are at high risk from venous thromboembolism. Thromboprophylaxis, both mechanical and chemical, is commonly administrated to reduce fatality from thromboembolism after surgery. However, there is no convincing evidence in the literature demonstrating that routine chemothromboprophylaxis reduces death rates from pulmonary embolus. Furthermore, it is unclear from the literature which thromboprophylactic agent, if any, should be used.

Recent NICE guidelines have recommended that heparin should be routinely administered to patients under-going THR to prevent thromboembolism, although it is unclear from the existing evidence if heparin is the most effective. However, research has suggested that aspirin, which is a low cost prophylactic agent, is effective in preventing DVT and PE after orthopaedic surgery. The aim of this study was to determine the 90-day mortality rate after THR using aspirin as a prophylactic agent.

Patients and Methods: Between 2003–2006, 2,286 patients underwent primary THR and 372 patients underwent revision hip replacement (RHR). Routine chemothromboprophylaxis consisting of aspirin 75mg daily for 6 weeks. In addition all patients were treated with anti-thromboembolic stockings. 40mg of subcutaneous clexane, in lieu of aspirin, was given daily to all patients who had previously suffered from a pulmonary embolus or deep venous thrombosis. Patients who died within 90 days of surgery had their death certificates examined. Retrieval at 90 days with regard to death was 100%.

Results:

Primary THR

One patient (0.04%) died within 30 days of surgery and a further 3 (0.13%) died between day 30 and day 90, giving a total mortality at 90 days of 0.17% (4/2,286). One patient (0.04%) died from PE and the other 3 patients (0.13%) died from non-vascular causes.

Discussion: This study found that the 30-day mortality rate for primary THR and RHR was 0.08% and the 90-day mortality rate was 0.23%. In this study, there was only one death from PE and no deaths from arterial complications. Therefore, although NICE guidelines suggest the use of heparin, this study found that routine aspirin administration is beneficial in protecting against early death after THR because of both thromboembolism and adverse arterial events.

We undertook a randomised controlled trial to compare the outcomes of skin adhesive and staples for skin closure in total hip replacement. The primary outcome was the cosmetic appearance of the scar at three months using a surgeon-rated visual analogue scale. In all, 90 patients were randomised to skin closure using either skin adhesive (n = 45) or staples (n = 45). Data on demographics, surgical details, infection and oozing were collected during the in-patient stay. Further data on complications, patient satisfaction and evaluation of cosmesis were collected at three-month follow-up, and a photograph of the scar was taken. An orthopaedic and a plastic surgeon independently evaluated the cosmetic appearance of the scars from the photographs. No significant difference was found between groups in the cosmetic appearance of scars at three months (p = 0.172), the occurrence of complications (p = 0.3), or patient satisfaction (p = 0.42). Staples were quicker and easier to use than skin adhesive and also less expensive. Skin adhesive and surgical staples are both effective skin closure methods in total hip replacement.

Introduction: Chronic joint pain is the primary reason for individuals electing to undergo TKR and therefore pain relief is an extremely important outcome after surgery. Although the literature suggests that TKR produces excellent pain relief, the prevalence of chronic pain after TKR is often masked in the reporting of mean pain scores. The aim of this study was to explore the prevalence, impact and onset of pain at 1-year after TKR.

Methods: 243 patients (251 knees) were recruited into a multi-centre randomised controlled trial comparing the outcomes of the Kinemax Plus fixed-bearing and mobile-bearing implant. Patients were assessed pre-operatively and then 3 months, 1-year and 2-years post-operatively. At each assessment time patients completed the WOMAC, KOOS quality of life scale, SF-12, American Knee Society Score, Satisfaction Scale for Joint Replacement Arthroplasty and a clinical examination. As part of the clinical assessment patients were asked to rate the pain in their knee as none, mild, occasionally moderate, continually moderate or severe.

Results: To date, 240 knees have reached their 1-year follow-up. Complete data regarding pain ratings was available for 198 patients. The mean age of patients was 68 years (range 40–81) and 52% were male. At 1-year after TKR, 13% of patients had occasionally moderate pain, 6% had continually moderate pain and 6% of patients had severe pain. In total, 25% patients reported moderate-severe pain at 1-year after TKR. 60% patients with pain at 1-year post-operative also experienced moderate-severe pain at 3 months post-operative. Using a Mann-Whitney U test, patients with moderate-severe pain at 1-year after TKR had significantly worse physical function (p< 0.001), knee-related quality of life (p< 0.001) and mental health scores (p< 0.05) than those patients with no-mild pain.

Conclusion: This study suggests the prevalence of pain after TKR is high, with 25% of patients reporting moderate-severe pain at 1-year after TKR. Pain experienced at 1-year post-operative was most frequently preceded by pain at 3-months post-operative, suggesting that for many patients a pain-free period after surgery is not experienced. The pain present at 1-year after TKR affected several domains of life, including functional ability, quality of life and mental health. Future research will focus on developing a pre-operative screening protocol to identify patients at risk of chronic pain after TKR.

This research was supported by funding from Stryker UK.

We compared patient-reported outcomes of the Kinemax fixed- and mobile-bearing total knee replacement in a multi-centre randomised controlled trial. Patients were randomised to the fixed- or the mobile-bearing prosthesis via a sealed envelope method after the bone cuts had been made in the operating theatre. Randomisation was stratified by centre and diagnosis. Patients were assessed pre-operatively and at eight to 12 weeks, one year and two years post-operatively. Validated questionnaires were used which included the Western Ontario MacMasters University, Short-Form 12, Mental Health Index-5, Knee Injury and Osteoarthritis Outcome Score for Knee-Related Quality of Life and Function in Sport and Recreation scales and a validated scale of satisfaction post-operatively. In total, 242 patients (250 knees) with a mean age of 68 years (40 to 80) were recruited from four NHS orthopaedic centres. Of these, 132 patients (54.5%) were women.

No statistically significant differences could be identified in any of the patient-reported outcome scores between patients who received the fixed-bearing or the mobile-bearing knee up to two-years post-operatively.

Our aim was to determine the pre-operative sporting profiles of patients undergoing primary joint replacement and to establish if they were able to return to sport after surgery. A postal survey was completed by 2085 patients between one and three years after operation. They had undergone one of five operations, namely total hip replacement, hip resurfacing, total knee replacement, unicompartmental knee replacement or patellar resurfacing. In the three years before operation 726 (34.8%) patients were participating in sport, the most common being swimming, walking and golf. A total of 446 (61.4%) had returned to their sporting activities by one to three years after operation and 192 (26.4%) were unable to do so because of their joint replacement, with the most common reason being pain. The largest decline was in high-impact sports including badminton, tennis and dancing. After controlling for the influence of age and gender, there was no significant difference in the rate of return to sport according to the type of operation.

Thromboprophylaxis after elective orthopaedic surgery remains controversial. Recent guidelines from the National Institute for Clinical Excellence (NICE) have suggested that low molecular weight heparin should be given to all patients undergoing total hip replacement. The British Orthopaedic Association is currently debating this guideline with NICE, as it is not clear whether published evidence supports this view. We present the early mortality in our unit after total hip replacement using aspirin as chemical thromboprophylaxis. The 30-day and 90-day mortality after primary total hip arthroplasty was zero. We compare this with that reported previously from our unit without using chemical thromboprophylaxis. With the introduction of routine aspirin thromboprophylaxis, deaths from cardiovascular causes have dropped from 0.75% to zero.

These results demonstrate that there is a strong argument for the routine administration of aspirin after elective total hip replacement.

The static properties of bone cements have been widely reported in the literature (Lewis, 1997, Khun, 2000, Armstrong 2002). Commercial bone cements are expected to perform above the minimum values in static tests specified by ISO 5833: 2002. It has been suggested that the viscoelastic properties of bone cement, such as creep and stress relaxation, might bear more relevance to the in-vivo behaviour of the cement-implant construct (Lee 2002). This study aimed to compare numerous properties of Simplex P, Simplex Antibiotic and Simplex Tobramycin and identify those properties most sensitive to subtle changes in cement composition. The three cements were chosen on the basis that they are characterised by the same liquid and powder compositions, the only difference being represented by the type and amount of added antibiotics. In Simplex Antibiotic the additives are 0.5g Erythromycin and 3 million I.U. Colistin, while in Antibiotic Simplex with Tobramycin the only additive is 0.5g of Tobramycin. The static properties of the cements were assessed following protocols described in ISO 5833: 2002, while the viscoelastic properties of the cement were measured with in-house developed apparatus in quasi-static conditions. Creep and stress relaxation tests were performed in four point bending configuration. Porosity was measured on the mid cross section of the creep samples using a digital image technique. All cements exhibited properties compatible with the ISO standard, but in plain Simplex the ISO minimum for bending and compressive strength was within the variation of the batches tested. Bending strength measurements were the least sensitive to differences in the cements. Plain Simplex displayed lower bending and compressive strength but higher bending modulus than the antibiotic laden options. The bending modulus could only discriminate between Simplex P and Simplex Antibiotic (p=0.02). Differences in the compressive strength of the three cements were significant, with the plain option being the weakest. Stress relaxation only discriminated between plain and Tobramycin loaded cement (p=0.028), while creep was more sensitive to differences and allowed distinction between plain and antibiotic loaded bone cements. The creep behaviour correlated with the cross sectional porosity measurements. This study demonstrated that the static tests specified by the current international standard are not as sensitive to subtle changes in the composition of the material as the time temperature dependent parameters characteristic of creep and stress relaxation. The authors advocate the evaluation of time and temperature dependent characteristics as a complement to the current standard.