Does measuring the range of motion of the hip and knee add to the assessment of disability in people undergoing joint replacement?

BACKGROUND AND HYPOTHESIS: Range of motion (ROM) is a core component of some commonly used measures of disability, such as the American Knee Society Score and Harris Hip Score. However, the relationship between ROM and function is contested. The aim of this cross-sectional analysis was to investigate the relationship between pre-operative range of motion (ROM) and disability in patients undergoing hip and knee joint replacement. PATIENTS AND METHODS: Two hundred and forty-nine patients recorded on NHS records as listed for joint replacement completed a range of measures prior to surgery. Pre-operative hip or knee ROM was measured by a trained research nurse using a hand-held goniometer. Joint pain severity was assessed using the WOMAC Pain Scale. Self-report activity limitations and participation restrictions were measured with the WOMAC Function Scale and the Aberdeen Impairment, Activity Limitation and Participation Restriction Measure. Observed activity limitations were assessed through three performance tests: 20-metre timed walk, sit-to-stand-to-sit, and 20-cm step tests. RESULTS: Pre-operative hip and knee ROM correlated weakly with self-report activity limitations (0.11 to 0.43), observed activity limitations (0.09 to 0.39) and self-report participation restrictions (-0.32 to 0.06). In comparison to ROM, correlations between joint pain and self-report activity limitations and participation restrictions were consistently moderate-high (-0.53 to 0.80). However, patients with restricted knee joint flexion (<110°) had significantly worse pain, activity limitations and participation restrictions than patients with non-restricted flexion (≥110°). Patients with restricted hip joint flexion (<95°) had greater activity limitations on some measures than patients with non-restricted flexion (>95°). DISCUSSION: This study suggests that modest restrictions of ROM are of little relevance to functional ability but that a certain amount of flexion is required for adequate function. We recommend that ROM is not the best means of assessing patients' disability prior to surgery. LEVEL OF EVIDENCE: III - cohort study.

The assessment of persistent pain after joint replacement.

This study used 'think aloud' to explore issues around using a standardised questionnaire to assess persistent pain after joint replacement. Twenty participants with moderate-extreme persistent pain in their replaced hip or knee completed the Chronic Pain Grade (CPG) while 'thinking aloud'. The interviews were audio-recorded, transcribed and analysed using thematic analysis. Completion of the CPG by patients was influenced by four issues: challenges with the question wording or response options on the CPG items; the fluctuating nature of pain and functional limitations; the need to account for co-morbidities and pain elsewhere; and adjustment to pain. These issues reflect those that have arisen previously in patients with musculoskeletal pain, and need to be considered when assessing persistent joint pain, both before and after joint replacement.

Assessment of the impact of flares in ankylosing spondylitis disease activity using the Flare Illustration.

OBJECTIVES: Many AS patients report periods of perceived higher disease activity (flares). This pilot study aims to document disease activity patterns reported by AS patients and examine associations with disease-specific health status measures. METHODS: Consecutive AS patients (n = 114) were asked whether they experience flares, and if they experience symptoms of AS between flares. They were shown the Flare Illustration of disease patterns over time and asked to select the pattern that best described their disease (i) since symptom onset and (ii) in the past year. Associations between reported disease pattern and disease activity (Bath AS Disease Activity Index, BASDAI); functional impairment (Bath AS Functional Index, BASFI); AS Quality of Life (ASQoL); Back Pain (Nocturnal and Overall) and demographic features were assessed in a subsample (n = 83) (statistical significance defined at P 70% of patients) and patterns with constant symptoms since onset (vs intermittent symptoms) were associated with worse health status (ASQoL: P = 0.007; BASDAI: P = 0.029; BASFI: P = 0.013, overall back pain: P = 0.025). CONCLUSIONS: Almost all AS patients report flares in disease activity: 70-80% report constant symptoms with single/repeated flares, while 20-30% report flares with no intermittent symptoms. The former is associated with a significantly poorer health status. These findings will be validated in a prospective study.

Economic evaluation of a rehabilitation program integrating exercise, self-management, and active coping strategies for chronic knee pain.

OBJECTIVE: To conduct an economic evaluation of the Enabling Self-Management and Coping with Arthritic Knee Pain through Exercise (ESCAPE-knee pain) program. METHODS: Alongside a clinical trial, we estimated the costs of usual primary care and participation in ESCAPE-knee pain delivered to individuals (Indiv-rehab) or groups of 8 participants (Grp-rehab). Information on resource use and informal care received was collected during face-to-face interviews. Cost-effectiveness and cost-utility were assessed from between-group differences in costs, function (primary clinical outcome), and quality-adjusted life years (QALYs). Cost-effectiveness acceptability curves were constructed to represent uncertainty around cost-effectiveness. RESULTS: Rehabilitation (regardless of whether Indiv-rehab or Grp-rehab) cost 224 pounds (95% confidence interval [95% CI] 184 pounds, 262 pounds) more per person than usual primary care. The probability of rehabilitation being more cost-effective than usual primary care was 90% if decision makers were willing to pay 1,900 pounds for improvements in functioning. Indiv-rehab cost 314 pounds/person and Grp-rehab 125 pounds/person. Indiv-rehab cost 189 pounds (95% CI 168 pounds, 208 pounds) more per person than Grp-rehab. The probability of Indiv-rehab being more cost-effective than Grp-rehab increased as willingness to pay (WTP) increased, reaching 50% probability at WTP 5,500 pounds. The lack of differences in QALYs across the arms led to lower probabilities of cost-effectiveness based on this outcome. CONCLUSION: Provision of ESCAPE-knee pain had small cost implications, but it was more likely to be cost-effective in improving function than usual primary care. Group rehabilitation reduces costs without compromising clinical effectiveness, increasing probability of cost-effectiveness.

Indications for total hip replacement: comparison of assessments of orthopaedic surgeons and referring physicians.

OBJECTIVES: To analyse differences of opinions on indications for primary total hip replacements (THRs) within and between groups of orthopaedic surgeons and the physicians who refer patients to them. METHODS: 22 orthopaedic centres in 12 European countries took part, resulting in a postal survey of 304 orthopaedic surgeons and 314 referring physicians. Each participant was asked to state what importance different domains (pain, functional impairment, physical examination and radiographs) have on their decision to recommend THR and to select the most appropriate level of severity of each symptom or sign for recommending THR. In addition, the participants were asked to prioritise other personal or environmental factors that affect their decision to undertake a THR. RESULTS: Rest pain, pain with activity and functional limitations were the most important criteria for THR, although range of motion and radiographic changes were of least importance. Both similarities and differences were observed within and between groups of surgeons and referring physicians in the overall approach to indications and the most appropriate level of severity of disease for recommending THR. Most surgeons agreed on severity levels in only 4 of 11 items and most referring physicians in only one. Between the groups, major differences occurred with regard to the importance of activities of daily living and the appropriate level of symptoms for THR. In general, compared with surgeons, referring physicians reported that the disease needed to be more advanced to warrant surgery. CONCLUSION: Currently, no consensus exists on objective indication criteria for THR. The observed differences between the gatekeepers (referring physicians) and surgeons can lead to variations and perhaps inequities in the provision of care.

Analysis of regional variation in hip and knee joint replacement rates in England using Hospital Episodes Statistics.

OBJECTIVES: Total hip and knee joint replacements are effective interventions for people with severe arthritis, and demand for these operations appears to be increasing as our population ages. This study explores regional variations in health care and inequalities in the provision of these expensive interventions, which are high on the UK Government's health agenda. STUDY DESIGN: The Hospital Episode Statistics (HES) for England were analysed. The HES database holds information on patients who are admitted to National Health Service (NHS) hospitals in England. METHODS: Age-standardized procedure rates were calculated using 5-year age groups with the English mid-year population of 2000 as the reference. Univariate associations between age-standardized operation rates and regional characteristics were assessed using Pearson's correlation coefficient. RESULTS: Age and sex-standardized surgery rates vary by 25-30%. For both hip and knee replacement, rates are highest in the South West and Midlands and lowest in the North West, South East and London regions. In the case of knee replacement, there are also marked differences in the sex ratios between regions. The variable that explained most variation in hip replacement rates was the proportion of older people in the region. In the case of knee replacement, the number of NHS centres offering surgery in the region was the main explanatory variable, with regions with fewer centres having the highest provision rates. CONCLUSION: These data can help to inform planning of services. They suggest that there may be inequities as well as inequalities in the provision of primary joint replacement surgery in England.

Trends in hip and knee joint replacement: socioeconomic inequalities and projections of need.

OBJECTIVES: To examine trends in primary and revision joint (hip and knee) replacement in England between 1991 and 2000. METHODS: Analysis of hospital episodes statistics between 1 April 1991 and 30 March 2001 for total hip replacement (THR) and total knee replacement (TKR). Descriptive statistics and regression modelling were used to summarise patients' demographic and clinical characteristics and to explore variations in joint surgery rates by age, sex, and deprivation. RESULTS: Between 1991 and 2000, the incidence of primary THR increased by 18%, while the incidence of revision THR more than doubled. The incidence of primary TKR doubled, with revision TKR increasing by 300%. Over the 10 year period, the proportion of THR episodes that involved revision operations rose from 8% to 20%. Substantial variations in operation rates by socioeconomic status were seen, with the most deprived fifth of the population experiencing significantly lower rates. Projections estimate that primary THR numbers could rise by up to 22% by the year 2010, with primary TKR numbers rising by up to 63%. CONCLUSIONS: Provision of joint replacement surgery in English NHS hospitals has increased substantially over the past decade. Revision operations in particular have increased markedly. The growth in primary operations has mostly occurred among those aged 60 years and over; rates among young people have changed very little. There is a significant deprivation based gradient in rates. If current trends continue there would be almost 47 000 primary hip and 54 000 primary knee operations annually by 2010.

Unmet need for joint replacement: a qualitative investigation of barriers to treatment among individuals with severe pain and disability of the hip and knee.

OBJECTIVE: To explore barriers to health-care utilization in respondents with moderate to severe hip/knee symptoms of pain and disability. METHODS: In-depth interviews were carried out with 27 participants who had high levels of hip/knee pain and disability (according to New Zealand scores). There were 10 men and 17 women; median age 76 yr (range 51-91). The data were analysed thematically using the constant comparison technique. RESULTS: Three types of barrier were identified: (i) people's own perceptions of need and reluctance to seek treatment, (ii) perceptions and experiences of primary care and (iii) experiences of treatment in secondary care. Pessimism about availability of treatments, and concerns about effectiveness and risks of surgery, made older people reluctant to seek medical help. Such views were often confirmed by GPs. Some of those referred to a hospital specialist were told that they were too young or too mobile for surgery. CONCLUSION: Barriers to treatment and unmet need for joint replacement exist in the UK, particularly amongst older people.

Who should have priority for a knee joint replacement?

OBJECTIVES: To explore patients' views on who should have priority for total knee replacement (TKR). METHODS: In-depth, semistructured interviews were conducted with 25 patients on the waiting list for a TKR. RESULTS: All participants were willing to comment on waiting lists and prioritization for TKR. Two major themes emerged: what they thought should happen, and what they thought did happen. They thought that priority should be based on length and degree of suffering, pain severity, immobility, paid employment, payment of National Insurance contributions, and caring for dependants. In contrast, they thought that what actually happened depended on age and weight, excessive complaining and access to private practice. CONCLUSIONS: The participants agreed with health professionals that pain and disability should be key criteria on which to prioritize people for a TKR. However, they also argued for a fair decision-making process that also included additional factors specific to the patient's circumstances. Criteria to aid prioritization for joint surgery need to accommodate the views of patients as well as professionals.

Population requirement for primary hip-replacement surgery: a cross-sectional study.

BACKGROUND: There has been a long-standing failure in many countries to satisfy the demand for several elective surgical treatments, including total hip replacement. We set out to estimate the population requirement for primary total hip replacement in England. METHODS: We undertook a cross-sectional study of a stratified random sample of 28,080 individuals aged 35 and over from 40 general practices in inner-city, urban, and rural areas of Avon and Somerset, UK. Prevalent disease was identified through a two-stage process: a self-report screening questionnaire (22,978 of 26,046 responded) and subsequent clinical examination. Incident disease was estimated from the point prevalence by statistical modelling. The requirement for total hip replacement surgery was estimated on the basis of pain and loss of functional ability, with adjustment for evidence of comorbidity and patients' treatment preferences. FINDINGS: 3169 people reported hip pain on the screening questionnaire. 2018 were invited for clinical examination, and 1405 attended. The prevalence of self-reported hip pain was 107 per 1000 (95% CI 101-113) for men and 173 per 1000 (166-180) for women. The prevalence of hip disease severe enough to require surgery was 15.2 (12.7-17.8) per 1000 aged 35-85 years. The corresponding annual incidence of hip disease requiring surgery was estimated as 2.23 (1.56-2.90), which suggests an overall requirement in England of 46,600 operations per year for patients who expressed a preference for, and were suitable for, surgery; the recent actual provision in England was about 43,500. INTERPRETATION: This research suggests that the satisfaction of demand for total hip replacement, given agreed criteria for surgery, is a realistic objective.

Quantitative serial assessment of patellofemoral joint osteoarthritis from lateral knee radiographs.

This study describes a new method for patellofemoral joint space measurement on lateral knee radiographs of patients from a case register of knee osteoarthritis (OA). The reproducibility of the technique was tested on 31 lateral radiographs and the validity, accuracy and sensitivity to change were examined in 82 patients (52 female, 30 male, mean age 66.5 years) with anteroposterior and lateral knee radiographs at two time points 3 years apart. The measurements were compared with visual assessments of joint space narrowing, subchondral sclerosis and osteophyte grade previously recorded by an independent observer. The degree of knee flexion was also recorded. The 'narrowest' joint space measurement was found to be a simple reproducible technique (coefficient of variation 8.5%). A significant correlation was found between the measured joint space and knee flexion. The reduction in measured joint space over 3 years was not significant (P = 0.067) but the group contained a large number of disease-free patellofemoral joints. The joint spaces were, however, significantly smaller in the presence of patellofemoral OA with or without tibiofemoral OA suggesting the technique to be valid. The measurements were also significantly smaller in the presence of a visual assessment of joint space narrowing and subchondral sclerosis. The mean measured joint space increased in the presence of severe osteophyte formation. This suggests that patellofemoral joint space measurement from lateral radiographs provides a sensitive and quantitative assessment of progression in OA at this articulation.

Scintigraphic assessment of osteoarthritis of the knee joint.

Clinical, radiographic, and scintigraphic abnormalities of the knee joint have been correlated in a cross sectional study of 100 patients with osteoarthritis. The group comprised 73 women and 27 men with a mean age of 65.7 years. One hundred and ninety one of the 200 knees had clinical (175) or radiographic (185) evidence of osteoarthritis, or both (161). Scintigraphic images of the knees were obtained 4-5 minutes (early phase) and 2.5-3.5 hours (late phase) after intravenous injection of 600 mBq of technetium-99m diphosphonate. Abnormal images were recorded in 162 knees (81%), and six different patterns were detected. Generalised isotope retention around the knee (early or late phase) was less common than focal areas of uptake around the joint margin (early or late phase) or in the patella or subchondral bone (late phase). Some knees with abnormal scans were normal on radiography (n = 7), or vice versa (n = 21). Different scan patterns correlated with different clinical and radiographic features: the generalised pattern correlated with pain (odds ratio (OR) = 45.1) and osteophytes (OR = 48.3); joint line retention correlated with subchondral bone sclerosis on radiography (OR = 62.1); and subchondral bone retention correlated with more severe radiographic changes. It is concluded that different patterns of scintigraphic abnormality reflect various aspects of the disease process of osteoarthritis.

Radiographic assessment of the knee joint in osteoarthritis.

The development of radiographic systems for the grading of osteoarthritis requires knowledge of the reproducibility of their individual component features. This paper reports the reproducibility, both within and between observers, for five commonly used radiographic features of osteoarthritis in the tibiofemoral and patellofemoral compartments of the knee joint. The results suggest that assessments of joint space narrowing, osteophyte, and bony contour in the tibiofemoral compartments are more reproducible than those of sclerosis and cyst. Patellofemoral assessments, with the exception of osteophyte, are considerably less reproducible between observers than tibiofemoral assessments.

Clinical assessment of osteoarthritis of the knee.

The repeatability of physical signs used to assess osteoarthritis of the knee has not been systematically examined. The within and between observer variation of 10 commonly used physical signs to determine osteoarthritis of the knee has been assessed here. The results obtained show variation in the repeatability of these signs. For those examining the tibiofemoral joints the repeatability was greater than for those examining the patellofemoral joint. It would therefore seem vital to take note of the repeatability of physical signs in determining the number of subjects to be studied in epidemiological studies and therapeutic studies in osteoarthritis.