Radiographic assessment of osteoarthritis: analysis of disease progression

Frailty prevalence according to the Survey of Health, Ageing and Retirement in Europe-Frailty Instrument (SHARE-FI) definition, and its variables associated, in patients with symptomatic knee osteoarthritis: findings from a cross-sectional study

Background

Frailty is a frequent condition in patients with knee osteoarthritis (KOA). However, there are different constructs on how to define it. Survey of Health, Ageing and Retirement in Europe-Frailty Instrument (SHARE-FI) is one of them.

Aim

To assess the prevalence of frailty, according to the SHARE-FI definition in patients with symptomatic KOA, and to establish its associated factors.

Methods

Symptomatic KOA patients were evaluated for pain symptoms, quality of life, comorbidities, ongoing drug therapy, and radiological damage. Patients were categorised according to the SHARE-FI definition into frail, pre-frail, and non-frail, and compared to a group of healthy controls associated by age and gender.

Results

170 symptomatic KOA patients (76.5% female, mean age 70.1 years) and 186 healthy controls were included. According to SHARE-FI criteria, 35 patients (20.6%) were categorised frail, 50 (29.4%) pre-frail, and 85 (50%) non-frail. The prevalence of frail or pre-frail subjects was statistically significantly higher in patients with symptomatic KOA. Stratifying the patients according to the frailty categories, frail subjects showed significantly higher mean values of pain. The results from logistic regression analysis revealed that polypharmacy (p = 0.003), pain (p = 0.016) and comorbidities (p = 0.035) were the variables independently associated with frailty in symptomatic KOA.

Discussion

Frailty or pre-frailty, defined by SHARE-FI, is common in symptomatic KOA. The main factors associated with frailty were polypharmacy, pain and comorbidity burden.

Conclusions

SHARE-FI can represent an useful tool to define frailty in symptomatic KOA.

The effect and mechanism of QufengZhitong capsule for the treatment of osteoarthritis in a rat model

Objective

The purpose of this study was to evaluate the therapeutic effects and mechanism of Qufeng Zhitong (QFZT)capsule for the treatment of osteoarthritis (OA) in a rat model.

Methods

8-10-week-old male Sprague–Dawley rats were randomly divided into the sham group (vehicle-treated), OA group (vehicle-treated), high-dose, middle-dose, low-dose of QFZT capsule-treated groups. OA was induced by transecting the medial collateral ligament and the medial meniscus in the right limb. The Sprague–Dawley rats were treated daily for 12 weeks with different concentrations of QFZT capsule: low (QFZT-L, 128 ​mg/kg), medium (QFZT-M, 256.5 ​mg/kg), and high (QFZT-H, 513 ​mg/kg) by gavage administration for a period of 4 and 12 weeks respectively. Vehicle-treated rats served as controls and administered 0.5% Carboxymethyl Cellulose Sodium (CMC-Na) by gavage on the same schedule. Weekly measurement of dynamic weight-bearing capacity, grip strength, joint swelling was were performed to monitor the progression of disease for 3 weeks. After euthanasia, the knee joints were articular cartilage changes. Pro-inflammatory gene expression in synovial joints was examined to assess the bone and cartilage changes. Gene expression of pro-inflammatory cytokines in synovial joints was measured to determine the therapeutic effect of QFZT.

Results

2 weeks after the treatment, the grip strength and weight-bearing capacity were significantly increased in the QFZT-M and QFZT-H groups, compared with the OA group. The joint widths were decreased significantly in the QFZT-L and QFZT- H groups, compared with the OA group as well. The mRNA level in the articular cartilage of knee joint of IL-1β in the QFZT-L group and IL-6 in the QFZT-H group was significantly suppressed at week 4, compared with the OA group. The radiology score was significantly decreased in the QFZT-H group compared with the OA group 12 weeks after treatment. Furthermore, the rats on QFZT treatment decreased the progression of OA, which was characterised by decreased cartilage degradation. However, the bone changes were no different in OA group and QFZT groups.

Conclusion

In a rat model of OA, QFZT capsule shows the tendency to reduce the destruction of cartilage, joint swelling and bone erosion which provides new evidence for the therapeutic potential of QFZT capsule in the treatment of OA in clinics.

The translational potential of this article

The QFZT capsule can improve the symptoms of the OA in rodent animal rats by attenuating pain and retarding cartilage damage. This study indicated that the QFZT capsule has the potential clinical application of in OA therapy.

Associations of Joint Line Tenderness and Patellofemoral Grind With Long-Term Knee Joint Outcomes: Data From the Osteoarthritis Initiative

OBJECTIVE

To examine whether joint line tenderness and patellofemoral grind from physical examination were associated with cartilage volume loss, worsening of radiographic osteoarthritis, and the risk of total knee replacement.

METHODS

This study examined 4,353 Osteoarthritis Initiative participants. For each measurement of joint line tenderness and patellofemoral grind, the patterns were defined as no (none at baseline and at 1 year), fluctuating (present at either time point), and persistent (present at both time points). Cartilage volume loss and worsening of radiographic osteoarthritis over 4 years were assessed using magnetic resonance imaging and radiographs, and total knee replacement over 6 years was assessed.

RESULTS

A total of 35.0% of participants had joint line tenderness, and 15.8% had patellofemoral grind. Baseline patellofemoral grind, but not joint line tenderness, was associated with increased cartilage volume loss (1.08% per year versus 0.96% per year; P = 0.02) and an increased risk of total knee replacement (odds ratio [OR] 1.55 [95% confidence interval (95% CI) 1.11-2.17]; P = 0.01). While the patterns of joint line tenderness were not significantly associated with joint outcomes, participants with persistent patellofemoral grind had an increased rate of cartilage volume loss (1.30% per year versus 0.90% per year; P < 0.001) and an increased risk of total knee replacement (OR 2.10 [95% CI 1.30-3.38]; P = 0.002) compared with those participants without patellofemoral grind.

CONCLUSION

Patellofemoral grind, but not joint line tenderness, may represent a clinical marker associated with accelerated cartilage volume loss over 4 years and an increased risk of total knee replacement over 6 years. This simple clinical examination may provide clinicians with an inexpensive way to identify those at higher risk of disease progression who should be targeted for surveillance and management.

Age affects joint space narrowing in patients with early active rheumatoid arthritis

BACKGROUND

Joint space narrowing (JSN) in rheumatoid arthritis (RA) may be a manifestation of (primary) osteoarthritis becoming more prominent with age. We investigated the severity and predictors of JSN progression among different age groups.

METHODS

10-year follow-up data of the BeSt study, a randomised controlled treat-to-target trial in early RA were used. Annual X-rays of hands and feet were scored using the Sharp/van der Heijde score (SHS). Subgroups were defined by age at baseline: ≥55, ≥40<55 and <40 years. JSN progression predictors were assessed by Poisson regression.

RESULTS

Baseline JSN scores (median (IQR)) were higher in patients ≥55 (2.0 (0.0-6.0)) compared with the other age groups: 1.0 (0.0-3.0) ≥40<55 and 0.3 (0.0-3.0) <40, p<0.001. After 10 years, total JSN and SHS were similar in all age groups. In patients ≥55 the mean erythrocyte sedimentation rate (ESR) over time (relative risk 1.02 (95% CI 1.00 to 1.03)) and the combined presence of rheumatoid factor and anticitrullinated protein antibodies (RF+/ACPA+) (3.27 (1.25-8.53)) were significantly correlated with JSN progression. In patients <40 the baseline swollen joint count (SJC; 1.09 (1.01-1.18)) and ESR over time (1.04 (1.02-1.06)) were significantly associated.

CONCLUSIONS

At baseline, patients with RA ≥55 years had more JSN than younger patients but after 10 years JSN scores were similar between age groups. Independent risk factors for JSN progression were baseline SJC and ESR over time in patients <40, RF+/ACPA+ and ESR over time in patients ≥55 years. This suggests that mechanisms leading to JSN progression are related to (residual) rheumatoid inflammation and vary between age groups. These mechanisms remain to be elucidated.

TRIAL REGISTRATION NUMBERS

NTR262, NTR265.

Defining the presence of radiographic knee osteoarthritis: a comparison between the Kellgren and Lawrence system and OARSI atlas criteria

PURPOSE

The Kellgren and Lawrence (K/L) system and Osteoarthritis Research Society International (OARSI) atlas are frequently used to define radiographic knee osteoarthritis (OA). The purpose of the current study was to determine the extent to which tibiofemoral OA rates differ between the K/L system and OARSI atlas criteria and to compare qualitative (K/L and OARSI) and quantitative (millimetres) measures of joint space narrowing (JSN).

METHODS

Posteroanterior radiographs of 1,178 knees, from 621 individuals with varying severity of OA, were graded by a trained physician with the K/L system (grade 0-4) and the OARSI atlas (osteophytes/JSN graded 0-3). Using the K/L system, the presence of OA was defined with the traditional cut-off of ≥grade 2 (definite osteophyte and possible JSN) and an alternative cut-off of at least a definite osteophyte alone (≥grade 2/osteophyte). For the OARSI atlas, OA was considered present if the sum of osteophytes or JSN ≥grade 2, or grade 1 JSN occurred in combination with grade 1 osteophyte. Minimum joint space width (mJSW) was measured manually in millimetres.

RESULTS

According to the K/L system (≥grade 2), 167 knees (14.2 %) had tibiofemoral OA and 203 (17.3 %) had ≥grade 2/osteophyte. In contrast, 309 knees (26.2 %) had tibiofemoral OA according to OARSI atlas criteria. K/L and OARSI JSN descriptions were significantly associated with mJSW (p < 0.022).

CONCLUSIONS

Radiographic tibiofemoral OA was almost twice as common using OARSI atlas criteria compared with the K/L system. This discrepancy is likely to contribute to the large variability of OA prevalence observed in the literature and is important for clinicians to consider when diagnosing radiographic OA. The cut-off for defining radiographic knee OA using the two systems should not be considered comparable.

LEVEL OF EVIDENCE

III.

Reliability of Assessing Hand Osteoarthritis on Digital Photographs and Associations With Radiographic and Clinical Findings

OBJECTIVE

To investigate the reliability and construct validity of an atlas for grading hand osteoarthritis (OA) on photographs in a separate younger community-dwelling population than the development cohort.

METHODS

Participants were community-dwelling adults (ages ≥50 years) in North Staffordshire, UK with hand pain or hand problems in the last year who attended a research clinic. High-quality photographs were taken in a standardized position. A photographic atlas was used to score hand joints (second and third distal interphalangeal [DIP], second and third proximal interphalangeal [PIP], and first carpometacarpal [CMC] joints) and joint groups (DIP, PIP, and CMC joints) for OA on a 0-3 scale. Hand radiographs were graded for OA using the Kellgren/Lawrence (K/L) grading system. Clinical features (nodes, bony enlargement, and deformity) were determined by physical examination. Associations of photographic hand OA grades with radiographic OA and clinical features were determined to assess construct validity.

RESULTS

In total, 558 participants (mean age 64 years, 62% women) were included in the analyses. Reliability for scoring OA on the photographs was good (mean intrarater intraclass correlation coefficient [ICC] 0.77 and mean interrater ICC 0.71). At the joint level, photographic hand OA grade was positively associated with radiographic OA grade (Spearman's ρ = 0.19-0.57, P < 0.001) and the number of clinical features (Spearman's ρ = 0.36-0.59, P < 0.001). At the person level, individuals with higher global photographic OA scores had higher summed K/L scores and higher percentages meeting the American College of Rheumatology clinical hand OA criteria.

CONCLUSION

This photographic scoring system was reliable and a good indicator of hand OA in a separate younger community-dwelling population than the development cohort. This method of data collection offers researchers a feasible alternative to physical examination and radiography.

Validating a new computed tomography atlas for grading ankle osteoarthritis

As the most common joint disease, osteoarthritis (OA) poses a significant source of pain and disability. It can be defined by classic radiographic findings, particular symptoms, or a combination of the 2. Although specific grading scales have been developed to evaluate OA in various joints, such as the shoulder, hip, and knee, no definitive classification system is available for grading OA in the ankle. The purpose of the present study was to create and validate a standardized atlas for grading (or staging) ankle osteoarthritis using computed tomography (CT) and "hallmark" findings noted on coronal, sagittal, and axial views extrapolated from the Kellgren-Lawrence radiographic scale. The CT scans of 226 patients at the Miami Veterans Affairs Medical Center were reviewed. An atlas was derived from a retrospective review of 30 remaining CT scans taken from July 2008 to November 2011. After this review, 3 orthogonal static CT images, obtained from 11 remaining patients, were chosen to represent the various stages on the OA scale and were used to test the validity of the atlas developed by 2 of us (M.M.C. and N.D.V.). A multispecialty panel of 9 examiners, excluding ourselves, independently rated the 11 CT scan subjects. The differences among examiners and specialties were calculated, including an intra-examiner agreement for 2 separate readings spaced 9 months apart. Although the small number of subspecialty examiners made the intraspecialty comparisons difficult to validate, the findings nevertheless indicated excellent agreement among all specialty groups, with good intra-investigational (intraclass correlation coefficient 0.962 and 1) inter-investigational (intraclass correlation coefficient 0.851) values. These results appeared to validate the CT ankle OA atlas, which we believe will be a valuable clinical and research tool, one that will likely be more beneficial than less relevant generalized OA grading scales in use today.

CT arthrography and anatomical correlation of the bare area of the ulnar trochlear fossa: a risk of misdiagnosis of cartilage ulcerations

AIMS

There is a variable bare area on the ulnar trochlear fossa that may be somehow interpreted as a cartilage defect. We aimed to correlate radiological images and dissections of this bare spot with CT arthrography imaging.

MATERIALS AND METHODS

We conducted a double study that included 10 unpaired fresh-frozen human cadaveric elbows (CT arthrography + dissection) and 40 CT arthrography of patients to investigate the 3-D architecture of the trochlear fossa of the ulna. Positioning, shape and measurements of the bare spot of each ulna were measured and correlated. A total of 40 were analyzed with this protocol of measurements to validate the anatomical findings.

RESULTS

The bare spot area is located 15.8 mm from the tip of the olecranon and 13.8 mm from the coronoid process (mean values). This area measures 4.1 mm in cranio-caudal plane, 2.2 mm in transversal plane. This area is located above a small subchondral tubercle that measures 1.0 mm in antero-posterior axis. No significant difference has been found between left and right elbow regarding its positioning and shape. A significant difference has been found between genders regarding the positioning of this area but not according to its shape.

CONCLUSION

The ulnar trochlear notch has a small area without cartilage. This bare area is located at the site of fusion of the different ossification center of the proximal ulna. It should not be interpreted as a chondral lesion. The existence of a subchondral tubercle clearly indicates that this uncovered zone is normal. Radiologist should consider this when interpreting elbow CT arthrography.

COMPARING QUALITY OF LIFE AMONG PEOPLE WITH DIFFERENT PATTERNS AND SEVERITIES OF KNEE OSTEOARTHRITIS

Objective: To identify what extent different patterns and severities of involvement affect quality of life of people suffering knee osteoarthritis.

Methods: This population-based survey involved 288 women and 288 men aged 40 years or older from Songkhla province, southern Thailand. Quality of life was measured using the Medical Outcome Study Short Form Health sutvery (SF-36) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic investigation included antero-posterior and skyline view of both knees. Osteoarthritis was categorized into 3 patterns; isolated patellofemoral, isolated tibiofemoral and combined with diagnosis based on Kellgren & Lawrence grade 2 or higher.

Results: Quality of life as measured by SF-36 and WOMAC showed poorer score in moderate or severe grade than in mild grade of severity. Isolated patellofemoral and combined patterns demonstrated showed poorer scores on both WOMAC and SF-36 than isolated tibiofemoral pattern. Body mass index, income level and pattern of involvement could independently predict total scores of WOMAC, while age, marital status and pattern of involvement affected total score of SF-36.

Conclusion: Pattern of involvement is a better predictor of quality of life than disease severity in patients with knee osteoarthritis.

Matrix metalloproteinases and inhibitors in cartilage tissue engineering

Inhibiting matrix metalloproteinase (MMP) activity has been considered as a potential therapeutic treatment that may modify the outcome for osteoarthritis (OA), a disease governed by abnormalities in the balance between MMPs and their inhibitors. Due to unexpected tissue fibrosis in early-phase clinical trials with some MMP inhibitors, possible divergent effects of inhibiting MMP activity on different cells are hypothesized. Therefore, we evaluated the effects of MMP inhibition on cells relevant to cartilage tissue engineering by culturing them in vitro in poly(ethylene glycol) diacrylate hydrogels to create 3D representations of cartilage tissue while allowing for local and direct administration of inhibitors. Mesenchymal stem cells demonstrated an inhibitor concentration-dependent decrease in extracellular matrix (ECM) deposition, while normal chondrocytes were mainly affected at the highest concentration of inhibitors. In contrast, the concomitant treatment of chondrocytes from patients with OA resulted in an increase in glycosaminoglycan content only in the presence of both inhibitors and anabolic growth factors. The observed upregulation of bone markers, however, indicates a delicate balance that must be addressed to therapeutically treat OA chondrocytes to stimulate more ECM production without errant bone formation. In conclusion, this study suggests that MMPs have complex interactions in both pathobiology and homeostasis.

Diagnostic imaging guideline for musculoskeletal complaints in adults-an evidence-based approach-part 2: upper extremity disorders

PURPOSE

To develop evidence-based diagnostic imaging practice guidelines to assist chiropractors and other primary care providers in decision making for the appropriate use of diagnostic imaging for upper extremity disorders.

METHODS

A comprehensive search of the English and French language literature was conducted using a combination of subject headings and keywords. The quality of the citations was assessed using the Quality of diagnostic accuracy studies (QUADAS), the Appraisal of Guidelines Research and Evaluation (AGREE), and the Stroke Prevention and Educational Awareness Diffusion (SPREAD) evaluation tools. The Referral Guidelines for Imaging (radiation protection 118) coordinated by the European Commission served as the initial template. The first draft was sent for an external review. A Delphi panel composed of international experts on the topic of musculoskeletal disorders in chiropractic radiology, clinical sciences, and research was invited to review and propose recommendations on the indications for diagnostic imaging. The guidelines were pilot tested and peer-reviewed by practicing chiropractors and by chiropractic and medical specialists. Recommendations were graded according to the strength of the evidence. Dissemination and implementation strategies are discussed.

RESULTS

Recommendations for diagnostic imaging guidelines of adult upper extremity disorders are provided, supported by over 126 primary and secondary citations. The overall quality of available literature is low, however. On average, 44 Delphi panelists completed 1 of 2 rounds, reaching over 88% agreement on all 32 recommendations. Peer review by specialists reflected high levels of agreement and perceived ease of use of guidelines and implementation feasibility.

CONCLUSIONS

The guidelines are intended to be used in conjunction with sound clinical judgment and experience and should be updated regularly. Future research is needed to validate their content.

Factors that may mediate the relationship between physical activity and the risk for developing knee osteoarthritis

Studies investigating the effect of physical activity on risk for developing osteoarthritis at weight-bearing joints have reported conflicting results. We examine evidence to suggest that this may be due to the existence of subgroups of individuals who differ in their response to physical activity, as well as methodological issues associated with the assessment of knee joint structure and physical activity. Recommendations for future studies of physical activity and the development of knee osteoarthritis are discussed.

A systematic search and narrative review of radiographic definitions of hand osteoarthritis in population-based studies

OBJECTIVE

Currently there is no agreed "gold standard" definition of radiographic hand osteoarthritis (RHOA) for use in epidemiological studies. We therefore undertook a systematic search and narrative review of community-based epidemiological studies of hand osteoarthritis (OA) to identify (1) grading systems used, (2) definitions of radiographic OA for individual joints and (3) definitions of overall RHOA.

METHODS

The following electronic databases were searched: Medline, Embase, Science Citation Index and Ageline (inception to Dec 2006). The search strategy combined terms for "hand" and specific joint sites, OA and radiography. Inclusion and exclusion criteria were applied. Data were extracted from each paper covering: hand joints studied, grading system used, definitions applied for OA at individual joints and overall RHOA.

RESULTS

Titles and abstracts of 829 publications were reviewed and the full texts of 399 papers were obtained. One hundred fifty-two met the inclusion criteria and 24 additional papers identified from screening references. Kellgren and Lawrence (K&L) was the most frequently applied grading system used in 80% (n=141) of studies. In 71 studies defining OA at the individual joint level 69 (97%) used a definition of K&L grade > or = 2. Only 53 publications defined overall RHOA, using 21 different definitions based on five grading systems.

CONCLUSION

The K&L scheme remains the most frequently used grading system. There is a consistency in defining OA in a single hand joint as K&L grade > or = 2. However, there are substantial variations in the definitions of overall RHOA in epidemiological studies.

New biochemical insights into the pathogenesis of osteoarthritis and the role of laboratory investigations in clinical assessment

Osteoarthritis (OA) is among the most frequent diseases in the population and a common cause of pain and disability in adults. The principal disease hallmarks for assessment of OA are still clinical observation and radiographic aspects. However, the efficacy of therapeutic interventions is complicated by the time required to observe radiographic signs, useful for both diagnosis and assessment. Thus, laboratory markers have received growing attention in recent years, in an attempt to improve diagnosis, assessment of disease activity and severity, and evaluation of therapeutic effects. Many biomarkers have been proposed, in particular those reflecting cartilage and bone turnover and synovitis. Among these, COMP, antigenic keratan sulphate, hyaluronan, YKL-40, type III collagen N-propeptide, and urinary glucosyl-galactosyl pyridinoline appear to be the most promising. However, serum or urinary determinations of these molecules are difficult to interpret adequately due to their complex metabolism. New ultrasensitive methods for C-reactive protein have improved the usefulness of this marker, especially in the assessment of disease activity. Routine examination of synovial fluid is still essential for diagnosis and includes leukocyte count and crystal detection; specialized testing includes the evaluation of the levels of markers of local inflammation such as metalloproteinases and cytokines, which appear to be crucial to the pathogenesis of OA.

Health-related quality of life in older adults with symptomatic hip and knee osteoarthritis: a comparison with matched healthy controls

BACKGROUND AND AIMS

Health-related quality of life (HRQOL) assessment is receiving increasing attention as an outcome measure in osteoarthritis (OA). The aims of this study were to compare HRQOL among older adults aged 55 to 78 years with hip and/or knee OA with those without OA, and to assess the influence of selected variables (sex, body mass index, radiographic OA severity, educational level, comorbidities) on HRQOL.

METHODS

The generic Medical Outcome Study Short Form-36 item health status questionnaire (SF-36) was administered to a cohort of 264 OA patients (105 with hip OA alone, 108 with knee OA alone, and 51 with both hip and knee OA) and 112 healthy controls.

RESULTS

Compared with the healthy controls, OA of the lower extremities has a detrimental effect on the eight-scale profile score, as well as on physical and mental summary measures of the SF-36. The most striking impact was seen in the physical measures "physical functioning", "physical role" and "pain" (p<0.0001). No statistically significant differences in SF-36 scores were found among the three groups of OA patients. The physical and mental summary scales of the SF-36 were closely correlated (p<0.0001). One hundred and forty-five patients (54.9%) reported at least one chronic coexisting disease. There was a significant inverse association with measures of comorbidity (number of comorbidities and comorbidity index score) and both physical and mental summary scores of the SF-36 questionnaire. In patients with OA of the knee alone (but not in hip OA alone or hip and knee OA), the SF-36 pain score was inversely correlated with years of formal education (p=0.016). In addition, the impact of hip and knee SF-36 dimensions was not influenced by the degree of radiographic severity.

CONCLUSIONS

Older adults with OA of the lower extremities undergo a significant impact on multiple dimensions of HRQOL, compared with healthy controls. The use of a generic measure of HRQOL such as the SF-36, in studies of OA where comorbidity is common, should be useful in characterizing the global burden of this disease.

Health-related quality of life in patients with hip or knee osteoarthritis: comparison of generic and disease-specific instruments

Health-related quality of life (HRQL) assessment is receiving increased attention as an outcome measure in osteoarthritis (OA). The aims of the study were to assess the health status impact of hip and knee OA in the general older population and to compare the metric properties of the WOMAC disease-specific questionnaire (Western Ontario and McMaster Universities) with generic measures [i.e., the Short Form 36 (SF-36) in patients with OA of the lower extremities]. This cross-sectional survey included a total of 244 patients (99 male, 145 female), aged 50 years and over, with symptomatic OA of the hips (107 patients) and knees (137 patients). All patients completed the WOMAC and the SF-36 questionnaires and were assessed for radiographic damage and for the presence of specific comorbid conditions. The overall impact on health was substantial for both groups of patients with OA of the lower extremities. The most striking impact was seen in OA of the hip for SF-36 "physical function" (p=0.03) and "physical role" (p=0.04), as well as WOMAC "physical function" (p=0.001). Furthermore, impairment of HRQL was only weakly associated with increasing radiographic changes. The SF-36 overall scores showed a better gradient with comorbidities than the WOMAC. This investigation has confirmed that WOMAC is the instrument of choice for evaluating patients with lower limb OA. For a more general insight into patient's health and in particular cross-sectional studies of the elderly, where comorbidity is common, the SF-36 should also be used. This study also provides an estimate of the impact of OA of the hip and knee on HRQL.