Diagnostic performance of bilateral false profile radiographs in early hip osteoarthritis.

OBJECTIVES: 1. To show that the anterior hip joint space is profiled only on the contralateral false profile radiograph. 2. To provide normal values of hip joint space width on anteroposterior and false profile radiographs. 3. To identify the best sites for joint space radiographic measurements to depict early hip osteoarthritis. METHODS: Anteroposterior and bilateral false profile radiographs of a cadaveric pelvis with markers around the anterior part of the hip joint were obtained. Joint space width was measured at ten sites on anteroposterior pelvis and bilateral hip false profile radiographs in 37 patients without hip pain (mean age, 59 years) and 65 patients with hip pain (mean age, 57.5 years), including 30 with and 35 without radiographic osteoarthritic subchondral bone changes. Between-groups differences in joint space width at each site were evaluated using ANOVA. The ability of joint space width at each site to discriminate between patients groups was investigated using logistic regression. RESULTS: The anterior joint space was only profiled on a contralateral false profile radiograph. Presumably, normal joint space widths were obtained in the group without hip pain. Joint space widths measured on the false profile radiographs differed significantly between the patient groups while measurements on the anteroposterior pelvis radiograph did not. CONCLUSIONS: Bilateral false profile radiographs profile the entire hip joint space, including its anterior part, and discriminate better between patients with and without hip pain than the anteroposterior pelvis radiograph. The AS/P joint space width ratio (anterosuperior/posterior) was the best parameter.

Randomised, controlled trial of avocado-soybean unsaponifiable (Piascledine) effect on structure modification in hip osteoarthritis: the ERADIAS study.

OBJECTIVE: To assess the ability of avocado-soybean unsaponifiable-Expanscience (ASU-E) to slow radiographic progression in symptomatic hip osteoarthritis (OA). METHODS: Prospective, randomised, double blind, parallel group, placebo controlled 3 year trial. Patients with symptomatic (painful ≥1 year, Lequesne Index between 3 and 10) hip OA (American College of Rheumatology criteria) and a minimum joint space width (JSW) of the target hip between 1 and 4 mm on a pelvic radiograph were randomly assigned to 300 mg/day ASU-E or placebo. Standing pelvis, target hip anteroposterior (AP) and oblique views were taken annually. The primary outcome was JSW change at year 3, measured at the narrowest point on pelvic or target hip AP view (manual measure using a 0.1 mm graduated magnifying glass). The full analysis dataset (FAS) included all patients having at least two successive radiographs. An analysis of covariance Mixed Model for Repeated Measurements with Missing at Random (for missing data) was performed to compare adjusted 3 year JSW changes (primary outcome) and the percentages of 'progressors' (JSW loss≥0.5 mm) between groups. RESULTS: 399 patients were randomised (345 kept in the FAS), aged 62 (35-84) years, 54% women, mean body mass index 27 (SD 4) kg/m(2), mean symptom duration 4 (SD 5) years, 0-100 normalised Lequesne Index 30 (SD 9) and global pain visual analogue scale 37 (SD 23) mm. Mean baseline JSW was 2.8 (0.9) mm. There was no significant difference on mean JSW loss (-0.638 mm vs -0.672 mm, p=0.72, in the ASU-E and placebo groups, respectively) but there were 20% less progressors in the ASU-E than in the placebo group (40% vs 50%, respectively, p=0.040). No difference was observed on clinical outcomes. Safety was excellent. CONCLUSIONS: 3 year treatment with ASU-E reduces the percentage of JSW progressors, indicating a potential structure modifying effect in hip OA to be confirmed, and the clinical relevance requires further assessment.

Anterior femoroacetabular impingement: an update.

Anterior femoroacetabular impingement can cause early hip osteoarthritis. The typical patient is an adult younger than 50 years of age, often with a history of sporting activities. The main symptom is intermittent pain triggered by static flexion (low seats) or dynamic flexion (during sporting or occupational activities that require repeated hip flexion). The characteristic physical finding is pain triggered by placing the hip in internal rotation and 70 to 110° of flexion. In additional to anteroposterior and false-profile radiographs, lateral Dunn or Ducroquet views should be obtained on both sides to visualize the anterior part of the head-neck junction. Instead of being concave, the head-neck junction is either flat or convex, causing a cam effect that damages the labrum and anterosuperior cartilage. Non-sphericity of the femoral head with an anterior ovoid bulge induces a similar cam effect. In pincer impingement, which is less common, over-coverage by the anterosuperior acetabular rim pinches the labrum between the rim and the femoral head-neck junction when the hip is flexed. Pincer impingement is related to acetabular retroversion or protrusion. Arthrography coupled with computed tomography or magnetic resonance imaging visualizes the morphological abnormalities (e.g., ovoid shape of the femoral head or retroversion of the acetabulum) and detects secondary lesions such as labral tears or separation or damage to the anterosuperior cartilage. Arthroscopy allows removal of the damaged labrum and correction of the morphological abnormalities via femoroplasty to restore the normal concave shape of the neck and/or acetabuloplasty to eliminate over-coverage. Short- or mid-term results are satisfactory in 75 to 80% of patients. However, the presence of degenerative lesions in about two-thirds of patients at the time of arthroplastic surgery limits the probability of achieving good long-term results.

Self-reported prevalence of psoriasis and evaluation of the impact on the natural history of hip osteoarthritis: results of a 10 years follow-up study of 507 patients (ECHODIAH study).

OBJECTIVE: The objective of the present study was to assess the frequency of self-reported psoriasis in a hip osteoarthritis (OA) cohort, and a secondary objective was to assess the course of hip OA with psoriasis. METHODS: ECHODIAH was a 3-year, randomised double-blind controlled trial evaluating diacerein vs. placebo in hip OA. During the 36 months of the trial, the Lequesne algofunctional index and pain visual analog scale (VAS) and joint space width (JSW) were assessed every 3 months. From month 36 to 120, the requirement for total hip replacement (THR) was collected annually via a phone call. At the end of 10 years of follow-up, the prevalence of self-reported psoriasis, family psoriasis was assessed by letter, retrospectively--(retrolective design). RESULTS: Of the 507 ECHODIAH patients, 279 were followed-up 10 years; 192 (68.8%) answered the psoriasis questionnaire. Twenty-two (11.4%) of 192 patients had self-reported psoriasis. Eighteen patients (9.4%) had family history of psoriasis. Eleven (50%) of 22 patients were diagnosed by a dermatologist. Baseline characteristics were similar between responders and non-responders, and between psoriasis and no psoriasis patients. The disease course was not different according to the presence of psoriasis, though total hip replacement was more frequent with psoriasis (77.2% after 10 years) than without (58.8%), no statistical difference (p=0.10). CONCLUSION: The prevalence of self-reported psoriasis was high in this cohort, almost twice the frequency reported in the general population. The disease course was not modified by the presence of psoriasis. These data should be further confirmed.

Prospective study of refractory greater trochanter pain syndrome. MRI findings of gluteal tendon tears seen at surgery. Clinical and MRI results of tendon repair.

OBJECTIVES: (1) To compare MRI and surgical findings in patients with refractory greater trochanter pain syndrome and (2) to assess surgical outcomes. METHODS: All consecutive patients seen between 2002 and 2006 by a single clinician were selected for surgical treatment according to the following criteria: (1) tendinopathy confirmed by physical tests; (2) painful disability persisting for at least 6 months despite treatment; (3) on MRI: area of high signal intensity on T2-weighted images, in the area of gluteus medius and/or minimus tendon; and (4) absence of marked muscle atrophy or fatty degeneration. Two musculoskeletal radiologists interpreted images by consensus. A single surgeon operated on all patients. RESULTS: Eight patients met the criteria for surgery. All were women, aged 71.1 (SD: 9.4). Mean symptoms duration before surgery: 14.3 months (11.8). Surgery confirmed the presence of a tear of the lateral part of the gluteus medius tendon in all eight patients, with an associated tear of its main tendon in one patient, all tears revealed on MRI. An associated tear of the gluteus minimus tendon was present at surgery in five patients, of which three were not seen on MRI (false negative). Bursitis was confirmed in all eight patients. Steady complete remission of spontaneous and provoked (physical examination) pain was observed in seven patients and partial remission in one (mean follow-up: 22.4 months (SD: 16.3)). Six MRIs performed after 20+/-12 months showed good reinsertion of the sutured tendon. CONCLUSION: The eight MR images of tear of the lateral part of the gluteus medius tendon were all confirmed at surgery. Three of five associated tendon tears (gluteus minimus only) were not seen on MRI. Surgical treatment was very effective in all patients but one.

[Misleading "hip" or buttock pain: proximal arteritis or lumbar spinal stenosis?]. / Douleurs ambiguës "de hanche" ou de fesse, artérite proximale ou canal lombaire sténosé?

Proximal arterial stenosis (bifurcation of the aortic, common iliac and especially hypogastric or hip arteries) can cause misleading 'hip' or buttock pain (two thirds of these cases involve the area of the trochanter, groin, or thigh). Their essential characteristic is that they cause patients to stop walking, improve in a minute or two and reappear when the patient starts walking again. Neither articular complications nor periarthritis of the hip fit this pattern, and physical examination and imaging exclude them. Neurogenic intermittent claudication is more difficult to rule out: it is 'often accompanied by paresthesia and anteflexion of the trunk to relieve the pain. A radiologic image of lumbar canal stenosis alone does not indicate that it is responsible for the pain: the stenosis may be asymptomatic and only fortuitously associated with the pain. The usual reduction in femoral pulse or ankle pressure index is absent if the stenosis is located on the hypogastric or gluteal artery and there is not substantial damage to the aorta-iliac axis. Arterial stenosis is confirmed by Doppler ultrasound. Arteriography is an examination performed during treatment, to guide angioplasty. It is indicated when medical treatment fails, as it frequently does.

Reproducibility and sensitivity to change of various methods to measure joint space width in osteoarthritis of the hip: a double reading of three different radiographic views taken with a three-year interval.

Joint space width (JSW) and narrowing (JSN) measurements on radiographs are currently the best way to assess disease severity or progression in hip osteoarthritis, yet we lack data regarding the most accurate and sensitive measurement technique. This study was conducted to determine the optimal radiograph and number of readers for measuring JSW and JSN. Fifty pairs of radiographs taken three years apart were obtained from patients included in a structure modification trial in hip osteoarthritis. Three radiographs were taken with the patient standing: pelvis, target hip anteroposterior (AP) and oblique views. Two trained readers, blinded to each other's findings, time sequence and treatment, each read the six radiographs gathered for each patient twice (time interval > or = 15 days), using a 0.1 mm graduated magnifying glass. Radiographs were randomly coded for each reading. The interobserver and intraobserver cross-sectional (M0 and M36) and longitudinal (M0-M36) reproducibilities were assessed using the intraclass coefficient (ICC) and Bland-Altman method for readers 1 and 2 and their mean. Sensitivity to change was estimated using the standardized response mean (SRM = change/standard deviation of change) for M0-M36 changes. For interobserver reliability on M0-M36 changes, the ICCs (95% confidence interval [CI]) were 0.79 (0.65-0.88) for pelvic view, 0.87 (0.78-0.93) for hip AP view and 0.86 (0.76-0.92) for oblique view. Intraobserver reliability ICCs were 0.81 (0.69-0.89) for observer 1 and 0.97 (0.95-0.98) for observer 2 for the pelvic view; 0.87 (0.78-0.92) and 0.97 (0.96-0.99) for the hip AP view; and 0.73 (0.57-0.84) and 0.93 (0.88-0.96) for the oblique view. SRMs were 0.61 (observer 1) and 0.82 (observer 2) for pelvic view; 0.64 and 0.75 for hip AP view; and 0.77 and 0.70 for oblique view. All three views yielded accurate JSW and JSN. According to the best reader, the pelvic view performed slightly better. Both readers exhibited high precision, with SRMs of 0.6 or greater for assessing JSN over three years. Selecting a single reader was the most accurate method, with 0.3 mm precision. Using this cutoff, 50% of patients were classified as 'progressors'.

Contribution of helical computed tomography to the evaluation of early hip osteoarthritis: a study in 18 patients.

OBJECTIVES: To show that helical computed tomography arthrograms (HCTA) with multiplanar reformations can document cartilage lesions and their characteristics in patients with suspected hip osteoarthritis and normal or inconclusive hip radiographs. METHODS: We retrospectively reviewed abnormal HCTAs from patients with mechanical hip pain and normal findings on anteroposterior and oblique ("faux profil") radiographs of the pelvis. HCTA in all patients consisted in acquiring 1 mm transverse slices and obtaining coronal and sagittal reformations. Radiographs and HCTAs were read separately by two experienced radiologists, who then worked together to reach a consensus. RESULTS: We identified 18 patients with abnormal HCTA findings and a full set of imaging studies. Mean age was 47.8 years, and there were 14 women and four men. Acetabular cartilage lesions were found consistently; they were often deep and predominated in the anterosuperior region. A labral fissure was noted in 12 patients. The sagittal and coronal reformations proved more informative than the acquired transverse slices. Interobserver reproducibility was excellent for the HCTA diagnosis of cartilage lesions. CONCLUSIONS: In patients with hip pain and normal radiographs, HCTA can provide a diagnosis of hip osteoarthritis by showing cartilage lesions, which are usually located in the anterosuperior part of the acetabulum.

Cross-sectional association of 10 molecular markers of bone, cartilage, and synovium with disease activity and radiological joint damage in patients with hip osteoarthritis: the ECHODIAH cohort.

OBJECTIVE: To investigate the associations of molecular markers of joint tissue turnover with clinical and radiological variables in patients with hip osteoarthritis (OA). METHODS: Patients of the ECHODIAH trial cohort (60% female; mean age 63 yrs, disease duration 5 yrs) fulfilling the American College of Rheumatology criteria for hip OA were studied. Pain was assessed using a 100 mm visual analog scale, and the presence of night pain and morning stiffness was observed as the index of joint inflammation. Joint space width (JSW) and subchondral bone sclerosis were assessed on hip radiographs. Ten markers were measured, 8 in serum: N-propeptides of collagen type I (PINP) and type III (PIIINP), cartilage oligomeric matrix protein (COMP), YKL-40, hyaluronan (HA), matrix metalloproteases (MMP1 and MMP3), and ultrasensitive C-reactive protein (CRP); and 2 in urine: C-terminal crosslinking telopeptides of collagen type I (CTX-I) and type II (CTX-II). Analyses of 376 patients with measurements of all the markers included principal component analyses to identify independent clusters of markers; followed by stepwise multivariate regressions to determine associations between markers, clinical variables, and radiographic signs of joint damage. RESULTS: Markers could be segregated into independent clusters: CTX-II, PINP, and CTX-I for cartilage degradation and bone turnover; COMP, PIIINP, and HA as potential markers of synovitis; and CRP and YKL-40, which are likely to indicate systemic inflammation; plus MMP1 and MMP3. After adjustment for age, sex, and body mass index, pain was significantly associated with CTX-II (p = 0.0095) and CRP (p = 0.046) and joint inflammation with COMP (p = 0.013). Radiographic signs of joint damage were associated with CTX-II (p = 0.001 for JSW; p = 0.007 for bone sclerosis). CONCLUSION: This cross-sectional study of OA molecular markers in a large cohort may provide biological evidence of different pathophysiological processes involved in hip OA. Among the markers measured, CTX-II showed the most consistent association with the symptoms and joint damage of OA.

Pitfalls in the accurate measurement of joint space narrowing in semiflexed, anteroposterior radiographic imaging of the knee.

OBJECTIVE: Computerized measurement of changes in joint space width (JSW) on serial radiographs of the knee in the semiflexed, anteroposterior (SF-AP) view has been used recently as a primary outcome measure in clinical trials of disease-modifying osteoarthritis drugs (DMOADs). In the use of fluoroscopy to achieve reproducible alignment of the medial tibial plateau and x-ray beam, the SF-AP radiographic protocol affords greater sensitivity in the detection of joint space narrowing (JSN) than that achieved by conventional radiographic positioning techniques. However, the utility of the SF-AP view is compromised by the variation in x-ray penetration in each examination, which may confound the correction of the automated measurement of JSW for the radiographic magnification inherent in an AP view of the knee. A recent DMOAD trial using the SF-AP protocol showed an improbable increase in JSW of > or =0.50 mm (i.e., greater than the measurement error). The present report provides an analysis of this problem, and the study aim was to demonstrate that substitution of the automated estimates of JSW with precise manual measurements can markedly reduce the problem attributable to radiographic magnification. METHODS: SF-AP radiographs were obtained at baseline and at 16 months and 30 months thereafter from subjects enrolled in a 6-center DMOAD trial. For each examination, a 6.35-mm steel ball was affixed to the skin over the head of the fibula to permit estimation of the percentage of radiographic magnification (%Mag) and correction of JSW measurements. Measurements of the minimum interbone distance (IBD) in the medial tibiofemoral compartment and the %Mag were obtained by an automated method (edge detection) and manually. Combinations of automated and manual measurements of the IBD and %Mag in estimates of magnification-corrected JSW were compared with respect to their reproducibility, agreement, and sensitivity to JSN. RESULTS: With fully automated measurements, variations in x-ray penetration in analog radiographs and edge enhancement in digital radiographs resulted in the computer "seeing" a metal ball whose diameter was artifactually reduced, resulting in an inflated measurement of JSW. Use of manual measurement of the IBD and %Mag largely eliminated these problems and reduced, from 16% to 2%, the frequency of knees exhibiting an increase in JSW > or =0.50 mm. In 14 of the 15 knees in which a significant increase in JSW was noted with the manual method, this increase in JSW could be explained by the development of significant lateral compartment narrowing during the study or poor alignment of the medial plateau. CONCLUSION: Although automated and manual methods of JSW measurement of the knee in the SF-AP view possess comparable intrareader reproducibility, the manual method is less susceptible to technical factors that affect the correction of raw JSW estimates for radiographic magnification. Until we can identify practical, effective solutions to these technical problems, use of any radiographic protocol involving AP imaging of the knee in a DMOAD trial must be viewed with caution.

Clinical and radiological evaluation of hip, knee and hand osteoarthritis.

Evaluation of hip, knee and hand osteoarthritis (OA) involves clinical and radiological outcome measures. Clinical, mainly visual analog scale (VAS) for pain, algofunctional or Lequesne's indices for hip and knee OA, Western Ontario and Mac Master Universities OA Index (WOMAC) for hip and knee OA, Dreiser's functional index for hand OA and some quality-of-life (QoL) indices are presented and discussed. Their utility is considered according to various uses: assessment of OA severity and course in therapeutic trials, in daily practice, as a help for surgical decision, and with regard to QoL as instruments for establishing the place of OA among differing chronic rheumatic conditions. Radiological assessment methods, especially for potential structure-modifying drug trials, mainly involve either manual measurement of joint space narrowing on radiographs over a period of several years, or measurement on X-ray digitized images. Last but not least, to conclude this review, we propose a selection of the most rapid and practical instruments allowing OA assessment in daily practice, with appropriate comments.

Description of the potential of an arthrometer for standard and reduced radiographs suitable to measurement of angles and segments of hip, knee, foot and joint space widths.

BACKGROUND: Primary osteoarthritis is usually selected in either epidemiological or therapeutic studies. This implies exclusions. Among cases of secondary osteoarthritis considered for either stratification or exclusion--or for prognosis and treatment in daily practice--are those due to architectural defects. Parameters of the latter should be measured to ascertain diagnosis. At present, measurements have to be performed either on digitized reduced films or standard radiographs. OBJECTIVE: To finalize an instrument capable of measuring the main angles and segments characteristic of the main dysmorphisms of the hip, knee and foot on different sizes of films. METHODS: An arthrometer drawn on transparent material to be placed on radiographs was designed, involving several appropriate protractors and millimetric scales; it was tested on 60 hip, 35 knee and 17 foot radiographs with various architectural defects. Angles and segments most often used according to literature were measured. Reduction rates of films were various, reflecting the range of radiograph sizes currently used in everyday practice. RESULTS: Measurements were easily performed on radiographs from standard (100%) up to 50% of reduction rate. So the arthrometer allows the recognition, especially in moderate, not obvious forms, of the following developmental or acquired dysmorphisms: hip congenital dysplasia and subluxation, including coxa valga and neck excess of anteversion; acetabular protrusion and coxa vara; tilt deformity; knee: patellar height abnormalities, patellar maltracking, trochlear depth insufficiency; foot: pes cavus, flatfoot. Angle and segment ratios do not change in reduced film, whereas segments (absolute lengths) obviously should be converted according to the reduction rate for retrieving the classical values established for decades. CONCLUSION: The arthrometer allows us to measure the relevant parameters of various dysmorphisms without drawing lines over the films themselves. It is suitable to reduced as well to standard radiographs. However, only the instrument and its ability to be used in various films sizes are here presented. Study of reproducibility of measurements--especially concerning the joint space width--remain to be performed.

[Osteoarthritis of the hip]. / Coxarthrose.

If all the etiological factors are taken into consideration, idiopathic coxarthrosis is less prevalent than formerly. Three factors are new or reappraised: sport practice (more than 10 years in competition), certain occupations (dancer, heavy load worker) and heritability. Three are classical and yet present: developmental dysplasias, acquired dysmorphias and traumas. Hip osteoarthritis should be followed up with the help of pain intensity measured on visual analog scale, algofunctional index and self-assessment of handicap. These 3 parameters--and not the X-ray image--are the basis of the decision for total hip replacement. However, the latter could be foreseen as necessary within the next 1-4 years when a rapid joint space narrowing is observed (about 5-7% of cases).

Structural effect of avocado/soybean unsaponifiables on joint space loss in osteoarthritis of the hip.

OBJECTIVE: To evaluate the structural effect of avocado/soybean unsaponifiables (ASU) in the treatment of patients with symptomatic osteoarthritis (OA) of the hip. METHODS: Patients with regular painful primary OA of the hip (European League Against Rheumatism 1980 criteria) and a joint space still > or = 1 mm (Kellgren grade 1 to 3, assessed by an independent observer prior to inclusion) entered a prospective, multicenter, randomized, parallel group, double-blind, placebo-controlled trial of 2 years duration. Patients had at least a 6-month history of regular pain and an algofunctional index (AFI) > or = 4. The primary assessment criterion was a decrease of the joint space width (JSW) on plain anteroposterior radiographs of the pelvis performed in standing position, measured at the narrowest points by 2 independent readers, previously tested and selected and blinded to both the treatment and the time sequence. Secondary criteria were standard clinical outcome measurements (AFI, pain on a visual analog scale, consumption of nonsteroidal antiinflammatory drugs and patient's and investigator's global assessments). RESULTS: One hundred sixty-three patients were included: 102 men and 61 women (mean age 63.2 +/- 8.7 years). A total of 108 patients (72 men and 36 women; mean age 64 +/- 7.9 years) were radiologically evaluable at 23.7 +/- 2.6 months (ASU group; n = 55) and 23.7 +/- 3.2 months (placebo group; n = 53). Overall comparison of the evolution of JSW showed no difference between the ASU and placebo groups, from 2.35 +/- 0.93 to 1.87 +/- 1.10 mm and from 2.5 +/- 0.94 to 1.9 +/- 1.33 mm, respectively (intergroup P value at end point = 0.9). When patients were divided into 2 subgroups according to the median value of the baseline JSW (2.45 mm), the joint space loss in the most severely affected subgroup of patients (baseline JSW < or = median) was significantly greater in the placebo group than in the ASU group: from 1.69 +/- 0.58 to 0.84 +/- 0.77 mm (-0.86 +/- 0.62 mm) and from 1.66 +/- 0.42 to 1.22 +/- 0.7 mm (-0.43 +/- 0.51 mm), respectively (P < 0.01). The JSW decrease was identical, with no difference in ASU and placebo groups, in the less severely affected subgroup of patients (baseline JSW > median). Clinical parameters in the 2 groups did not differ significantly throughout the study. CONCLUSION: This pilot randomized, double-blind, placebo-controlled trial failed to demonstrate a structural effect of ASU in hip OA. However, in a post-hoc analysis, ASU significantly reduced the progression of joint space loss as compared with placebo in the subgroup of patients with advanced joint space narrowing. These results suggest that ASU could have a structural effect but require confirmation in a larger placebo-controlled study in hip OA.

A composite index for total hip arthroplasty in patients with hip osteoarthritis.

OBJECTIVE: We propose a composite index for considering total hip arthroplasty (THA) in hip osteoarthritis (OA). METHODS: We carried out a 3 year longitudinal study of patients with painful hip OA from 137 centers. Clinical data were collected at baseline and every 3 months; radiographs were taken at entry and each year. The decision to have surgery was made by the patient, the rheumatologist, and the surgeon, with no reference to outcome measures. Statistical analysis included discrete Cox analysis with time dependent covariates, on 3 month interval grouped data. The dependent variable was THA during the 3 months following the evaluated visit. Time dependent covariates collated at each evaluated visit included radiological joint space width (JSW), percentage decrease in JSW during the year preceding, patient's global assessment. Lequesne index, pain, and nonsteroidal antiinflammatory drug and analgesic intake. We compared 2 analyses differing in symptomatic variables entered: values obtained at a single time point vs mean values between 2 visits at a 3 month interval. Selection of the index was based on the best combination of variables to predict occurrence of THA. RESULTS: Of the 508 patients recruited for study, 42 were excluded. During the 3 year followup, 75 patients underwent THA. Symptomatic, therapeutic, and radiological variables were included in the index resulting from the 2 analyses. Based on the selected cutoff, the positive and negative predictive values for occurrence of THA in the 2 years following were 54.3 and 90.6%, respectively (single point model), and 52.9 and 86.7%, respectively (model using mean values of symptomatic variables between 2 visits). CONCLUSION: The poor positive predictive value of the composite indices obtained in this study suggests that there are other unmeasured factors determining access to surgery. On the other hand, the high negative predictive values suggest that these composite measures should be used by clinicians to determine which patients should not be referred to THA.