L. Brunton

The Impact of Leg Length Discrepancy on Patient Satisfaction and Functional Outcome Following Total Hip Arthroplasty

A series of 191 patients undergoing THA with a standardised stem were studied. The effect of leg length discrepancy (LLD) on patient function (Oxford Hip Score), health measures (Short Form 12) and satisfaction (Self-Administered Patient Satisfaction Scale) at a mean 3.8 years of follow up (range 3.3 to 4.9) is reported. 8.9% of cases had shortening, 0.5% no LLD and 90.6% had lengthening. In 21.5% the LLD was more than 10mm, in 37.1% 5-10mm, and in 40.9% 0-5mm. There was no significant difference in patient reported outcome measures (PROMs) according to LLD. Correlation of recorded measurements between multiple observers was excellent (0.93). LLD following total hip arthroplasty remains common but in this series, was not correlated with PROMs.

Physical Activity and Bone: May the Force be with You

Physical activity (PA) is thought to play an important role in preventing bone loss and osteoporosis in older people. However, the type of activity that is most effective in this regard remains unclear. Objectively measured PA using accelerometers is an accurate method for studying relationships between PA and bone and other outcomes. We recently used this approach in the Avon Longitudinal Study of Parents and Children (ALSPAC) to examine relationships between levels of vertical impacts associated with PA and hip bone mineral density (BMD). Interestingly, vertical impacts >4g, though rare, largely accounted for the relationship between habitual levels of PA and BMD in adolescents. However, in a subsequent pilot study where we used the same method to record PA levels in older people, no >4g impacts were observed. Therefore, to the extent that vertical impacts need to exceed a certain threshold in order to be bone protective, such a threshold is likely to be considerably lower in older people as compared with adolescents. Further studies aimed at identifying such a threshold in older people are planned, to provide a basis for selecting exercise regimes in older people which are most likely to be bone protective.

Trajectories of Pain and Function after Primary Hip and Knee Arthroplasty: The ADAPT Cohort Study

Background and Purpose Pain and function improve dramatically in the first three months after hip and knee arthroplasty but the trajectory after three months is less well described. It is also unclear how pre-operative pain and function influence short- and long-term recovery. We explored the trajectory of change in function and pain until and beyond 3-months post-operatively and the influence of pre-operative self-reported symptoms. Methods The study was a prospective cohort study of 164 patients undergoing primary hip (n = 80) or knee (n = 84) arthroplasty in the United Kingdom. Self-reported measures of pain and function using the Western Ontario and McMaster Universities Osteoarthritis index 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 regression models were used for each outcome (pain and function), and the trajectories of change were charted (0–3 months and 3–12 months). Results Hip: Most improvement occurred within the first 3 months following hip surgery and patients with worse pre-operative scores had greater changes. The mean changes observed between 3 and twelve months were statistically insignificant. One year after surgery, patients with worse pre-operative scores had post-operative outcomes similar to those observed among patients with less severe pre-operative symptoms. Knee: Most improvement occurred in the first 3 months following knee surgery with no significant change thereafter. Despite greater mean change during the first three months, patients with worse pre-operative scores had not ‘caught-up’ with those with less severe pre-operative symptoms 12 months after their surgery. Conclusion Most symptomatic improvement occurred within the first 3 months after surgery with no significant change between 3–12 months. Further investigations are now required to determine if patients with severe symptoms at the time of their knee arthroplasty have a different pre-surgical history than those with less severe symptoms and if they could benefit from earlier surgical intervention and tailored rehabilitation to achieve better post-operative patient-reported outcomes.

Assessing function in patients undergoing joint replacement: a study protocol for a cohort study

BackgroundJoint replacement is an effective intervention for people with advanced arthritis, although there is an important minority of patients who do not improve post-operatively. There is a need for robust evidence on outcomes after surgery, but there are a number of measures that assess function after joint replacement, many of which lack any clear theoretical basis. The World Health Organisation has introduced the International Classification of Functioning, Disability and Health (ICF), which divides function into three separate domains: Impairment, activity limitations and participation restrictions. The aim of this study is to compare the properties and responsiveness of a selection of commonly used outcome tools that assess function, examine how well they relate to the ICF concepts, and to explore the changes in the measures over time.Methods/designTwo hundred and sixty three patients listed for lower limb joint replacement at an elective orthopaedic centre have been recruited into this study. Participants attend the hospital for a research appointment prior to surgery and then at 3-months and 1-year after surgery. At each assessment time, function is assessed using a range of measures. Self-report function is assessed using the WOMAC, Aberdeen Impairment, Activity Limitation and Participation Restriction Measure, SF-12 and Measure Yourself Medical Outcome Profile 2. Clinician-administered measures of function include the American Knee Society Score for knee patients and the Harris Hip Score for hip patients. Performance tests include the timed 20-metre walk, timed get up and go, sit-to-stand-to-sit, step tests and single stance balance test. During the performance tests, participants wear an inertial sensor and data from motion analysis are collected. Statistical analysis will include exploring the relationship between measures describing the same ICF concepts, assessing responsiveness, and studying changes in measures over time.DiscussionThere are a range of tools that can be used to assess function before and after joint replacement, with little information about how these various measures compare in their properties and responsiveness. This study aims to provide this data on a selection of commonly used assessments of function, and explore how they relate to the ICF domains.

Direct thrombin inhibitor (DTI) vs. aspirin in primary total hip and knee replacement using wound ooze as the primary outcome measure. A prospective cohort study

The latest NICE guidance dictates that all patients undergoing lower-limb arthroplasty should be prescribed potent venous thromboembolic (VTE) prophylaxis. However, use of potent anti-thrombotics is likely to lead to increased post-operative wound ooze. Postoperative wound ooze is associated with increased risk of infection. This study used a prospective, consecutive, multi-surgeon sample of 110 patients undergoing primary total hip replacement (THR) and total knee replacement (TKR) prescribed either direct thrombin inhibitor (DTI) (n=51, 26 males: 25 females, age 69 ±18) or aspirin (n=59, 25 males: 34 females, age 69 ± 19). Hospital stay, body mass index (BMI), wound length and patient demographics were documented along with a daily assessment of wound ooze. The use of DTIs was associated with a significant increase in mean days to dryness in both THR (6.2 ± 0.98, 95% C.I. 5.2–7.1) and TKR (6.6 ± 1.89, 95% C.I. 4.7–8.5) compared to aspirin in THR (3.0 ± 1.03, 95% C.I 1.9–4.0) and TKR (3.4 ± 1.21, 95% C.I 2.2–4.6) with p-values of <0.0001 and 0.0024 for THR and TKR respectively. Age, gender and wound length were not found to be significant confounding variables. DTIs proven benefit in lowering venous thromboembolism when compared with aspirin needs to be balanced with their increased cost and increased duration of wound ooze.

Assessment of physical function following total hip arthroplasty: Inertial sensor based gait analysis is supplementary to patient-reported outcome measures

BACKGROUND Functional outcome assessment after total hip arthroplasty often involves subjective patient-reported outcome measures whereas analysis of gait is more objective. The studys aims were to compare subjective and objective functional outcomes after total hip arthroplasty between patients with low and high self-reported levels of pre-operative physical function. METHODS Patients undergoing total hip arthroplasty (n=36; m/f=18/18; mean age=63.9; SD=9.8 years; BMI=26.3; SD=3.5) were divided into a low and high function subgroup, and prospective measures of WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) function score and gait were compared at baseline and 3 and 12 months post-operatively. FINDINGS WOMAC function scores significantly improved in both low and high function subgroups at 3 months post-operatively whereas gait parameters only improved in patients with a low pre-operative function. Between 3 and 12 months post-operatively, WOMAC function scores had not significantly further improved whereas several gait parameters significantly improved in the low function group. WOMAC function scores and gait parameters were only moderately correlated (Spearmans r=0.33-0.51). INTERPRETATION In a cohort of patients undergoing total hip arthroplasty, pre-operative differences in mean WOMAC function scores and gait parameters between low and high function subgroups disappeared by 3 months post-operatively. Gait parameters only improved significantly during the first 3 post-operative months in patients with a low pre-operative function, highlighting the importance of investigating relative changes rather than the absolute changes and the need to consider patients with high and low functions separately.

Assessing the health status of people with arthritis: example of osteoarthritis of the knee

Over the past few decades many articles about outcome measures have been published. A variety of selfassessment instruments are now available to help assess the health status of people with almost any disease [1]. The drive to develop more and better outcome instruments has been part of evidence-based medicine, which has been led by the need to find reliable and valid ways of assessing the response to interventions in clinical trials. The use of such instruments certainly helps the researchers who develop them, but do they help the clinician? Here we argue that they do not, and using the example of OA of the knee, we suggest that simpler approaches are needed for routine clinical practice. In the case of OA of the knee, research organizations such as the Outcome Measures in Rheumatoid Arthritis Clinical Trials (OMERACT)/Osteoarthritis Research Society International (OARSI) [2] and Group for the Respect of Ethics and Excellence in Science (GREES) [3] recommend that pain severity, disability and quality of life should be assessed using validated, standardized self-assessment measures such as the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and EuroQol-5D (EQ-5D). But the clinician may need to take a different approach. Pain is the dominant symptom for most people with OA. Usually researchers just assess severity, using many different self-assessment approaches, although many new and more complicated ways to assess pain, such as quantitative sensory testing [4], are now available and recommended for use in research. Qualitative work on people with OA of the knee shows that they have two types of pain: their constant, usual pain and more distressing, intermittent attacks of pain [5]. In addition, they are often as distressed by fatigue as they are by pain. So clinicians need simple ways to assess constant pain, intermittent pain and fatigue—perhaps with the use of face charts. If clinicians do ask about these issues, it shows the patient that they understand the symptoms the patient is experiencing. Rheumatologists have used a restricted approach to assess disability, generally using self-assessment of standard activities of daily life such as walking or dressing. The International Classification of Functioning, Health and Disability (ICF) framework [6] reveals the weakness of such measures, as they ignore the key issue of participation in society. People with OA of the knee often say that what they want most is to be able to play with their grandchildren or to go out to a social club; thus we need to assess such functions along with the limitations to important activities such as the ability to walk. However, it is becoming apparent that self-assessment of activities and participation may not always be very reliable. More objective means of assessment, such as timed walking tests or sophisticated accelerometry, may be better [7]. But such clever, time-consuming and difficult tests do not help clinicians; they need a simple test that can be done in the clinic. Observing the ability of a patient to squat or to climb a step might work, but we need more research on the value of these simple tests. Quality of life measures, such as EQ-5D, are preferred by researchers, as they can be used to assess costeffectiveness. Moreover, measures such as the Short Form 36 (SF-36) are used because everyone uses them, and because we (the academics) prefer using some global, holistic-sounding assessment of quality of life of our patients, even if we have very little idea of what that means. The clinician, in contrast, needs to understand the needs and values of the individual patient in order to understand what matters most to that patient and to be able to tailor the disease management. Perhaps use of the Measure Yourself Medical Outcome Profile (MYMOP) [8], which allows patients to state what problems are most important to them and rate them, would be of more clinical value than the SF-36? Researchers tend to study homogeneous groups of patients who only have a single problem. However, life is not so simple. Most people with OA of the knee who are seen by clinicians have a range of other medical and social problems. As OA is age related, comorbidities are usually present, and may be more important to function and quality of life than the OA itself. For example, Ayis et al. [9] have shown that OA alone has little effect on the ability to walk, but if combined with a sensory problem such as reduced eyesight or a psychological problem such as depression, the impact can be immense. So the clinician needs to assess the patient as a whole and not just the disease alone. Finally, we agree with Paterson et al. [10], who argue that the idea behind outcome measures in health care is inappropriate for chronic illnesses, as there is no clearly defined point of outcome. Instead, it is a constantly changing journey and a narrative of the patient’s altering health status in the context of adaption to a changing environment.