Association of radiographic features of osteoarthritis of the knee with knee pain: data from the Baltimore Longitudinal Study of Aging

Correlation between radiographic severity of knee osteoarthritis and future disease progression. Results from a 3-year prospective, placebo-controlled study evaluating the effect of glucosamine sulfate

OBJECTIVE

To investigate the relationship between baseline radiographic severity of knee osteoarthritis (OA) and the importance of long-term joint space narrowing.

DESIGN

Sub-analysis from a three-year randomized, placebo-controlled, prospective study, of 212 patients with knee OA, recruited in an osteoarthritic outpatient clinic and having been part of a study evaluating the effect of glucosamine sulfate on symptom and structure modification in knee OA.

MATERIAL AND METHODS

Measurements of mean joint space width (JSW), assessed by a computer-assisted method, were performed at baseline and after 3 years, on weightbearing anteroposterior knee radiographs.

RESULTS

In the placebo group, baseline JSW was significantly and negatively correlated with the joint space narrowing observed after 3 years (r=-0.34, P=0.003). In the lowest quartile of baseline mean JSW (<4.5mm), the JSW increased after 3 years by (mean (S.D.)) 3.8% (23.8) in the placebo group and 6.2% (17.5) in the glucosamine sulfate group. The difference between the two groups in these patients with the most severe OA at baseline was not statistically significant (P=0.70). In the highest quartile of baseline mean JSW (>6.2mm), a joint space narrowing of 14.9% (17.9) occurred in the placebo group after 3 years while patients from the glucosamine sulfate group only experienced a narrowing of 6.0% (15.1). Patients with the most severe OA at baseline had a RR of 0.42 (0.17-1.01) to experience a 0.5mm joint space narrowing over 3 years, compared to those with the less affected joint. In patients with mild OA, i.e. in the highest quartile of baseline mean JSW, glucosamine sulfate use was associated with a trend (P=0.10) towards a significant reduction in joint space narrowing.

CONCLUSION

These results suggest that patients with the less severe radiographic knee OA will experience, over 3 years, the most dramatic disease progression in terms of joint space narrowing. Such patients may be particularly responsive to structure-modifying drugs.

Osteoarthritis of the peripheral joints

Osteoarthritis (OA) is a complex process affecting many different joint areas in the body. From a pathophysiological point of view some features are crucial for the diagnosis, such as cartilage fibrillation and thinning, subchondral sclerosis and the presence of osteophytes. From a clinical perspective, OA is the most prevalent rheumatic joint disorder, causing pain and stiffness of the joints and, for the individual, impaired function and health status. The aim of this chapter is to present current knowledge of definitions of OA, its presence in different populations and in different joint areas (the back excluded). Furthermore, methods of diagnosing and delineating clinically relevant forms of OA, now and in the future, are presented as well as current knowledge of the risk factors for developing and the factors for preventing OA.

The natural history of emergent osteoarthritis of the knee in women

OBJECTIVE

We assessed the probability that mid-aged women with a Kellgren and Lawrence (K-L) score of 1 are likely to progress to a score of 2 or regress to a score of zero at a second time point, 2-3 years later.

METHODS

Osteoarthritis (OA) of measurements (weight-bearing X-rays and interviews) were undertaken in women from the Southeast Michigan population who were > or =40 years of age, and who participated in both the 1995 and 1998 measurements (N=679).

RESULTS

Of the 17.1 % of women with a 1995 K-L score of 1 in their right knee, 37.1% had a K-L score of 1 in 1998 while 32.8 % had a score of > or =2 and 30.2% had a score of zero. For 26.0% of women, the score progressed by at least one unit over the 2.5 year period whereas scores for only 7.0% of women regressed in the same time period. Women who had a K-L score of 1 in the right knee in 1995 were 2.5 times more likely to have a K-L score of 1 in 1998 (95% CI=1.6-3.8); and were 2.2 times more likely to have a K-L score of 2 or greater (95% CI=1.4-3.5) in 1998 compared with other scores. These women were 74% less likely to have a score of zero in 1998 (95% CI=0.2-0.4). Further, other risk factors, specifically age and BMI were predictors of increasing K-L grade in 1998.

CONCLUSION

These findings suggest that a score of 1 is part of the advancement to emergent OAK; and suggest the following criteria to characterize individuals who are at an intervenable stage on the pathway toward OAK: age > or =40, BMI > or =30, and K-L score of > or =1. From the perspective of both the individual and the examiner, these assessment characteristics are relatively simple to assess clinically.

The experience of pain and emergent osteoarthritis of the knee

Discrepancies exist between radiographic osteoarthritis of the knee (OAK) and report of knee joint pain. Little is known about how these two definitions of osteoarthritis (OA) and their correlates differ between African American (AA) and Caucasian (CA) women.

OBJECTIVE

We compared the prevalence of radiographic OAK and knee joint pain in AA and CA women, and the congruency of these outcomes according to age, body size, and knee injury.

DESIGN

A cross-sectional study of African American and Caucasian women aged 40-53 years (N=829) in Southeast Michigan used the Kellgren and Lawrence Atlas of Standard Radiographs of Arthritis to characterize radiographs of both knee joints (weight bearing) and self-report of knee pain.

RESULTS

Current pain was a significantly more sensitive predictor of radiographic OAK among AA women (Se=0.51) compared to CA women (Se=0.35). Specificity was similar between AA women (Sp=0.77) and CA women (Sp=0.82). Positive predictive value was significantly greater for AA compared with CA women (PV+=0.40 and PV+=0.15, respectively). The odds of having radiographic OAK increased with BMI >32 kg/m(2) in both groups. Knee pain was related to BMI in CA women, but not AA women. Previous knee injury was associated with knee pain in both AA and CA women (OR=3.0 and OR=2.4).

CONCLUSIONS

Joint pain in AA women was more likely to be associated with radiographic OAK as compared with CA women. This suggests differences in these two groups in both how pain is experienced in the OAK process and in the prevalence of non-OAK related pain in knee joints.

Impact of pain on disability among older Mexican Americans

BACKGROUND

Joint pain is a very common complaint among elderly persons and may lead to functional disability. The purpose of this study is to estimate the prevalence of self-reported pain on weight bearing and its impact on the 2-year incidence of limitation in lower-body activities of daily living (ADL) in initially nondisabled Mexican American elderly subjects.

METHODS

We studied a probability sample of 2167 noninstitutionalized Mexican American men and women aged 65 or older residing in five Southwestern states. Subjects were asked about pain on weight bearing, ADL, depressive symptomatology, and the presence of chronic diseases. The body mass index was computed using measured height and weight. Finally, a three-task (tandem balance, 8-foot walk, and repeated chair stands), performance-based, lower-body function test was performed.

RESULTS

The overall prevalence of pain on weight bearing in the sample was 31.9%, with 37.7% for women versus 24.0% for men (p <.001). The most prevalent sites of pain were knees (14.7%), followed by ankle/feet (12.1%). In a logistic regression analysis, pain was a significant independent predictor of subsequent disability and of the inability to perform tandem balance, 8-foot walk, and repeated chair stands.

CONCLUSIONS

Pain on weight bearing is prevalent among older Mexican Americans and is a major independent risk factor for subsequent disability.

Long-term outcome of meniscectomy: symptoms, function, and performance tests in patients with or without radiographic osteoarthritis compared to matched controls

OBJECTIVE

To describe the long-term influence of meniscectomy on pain, functional limitations, and muscular performance. To assess the effects of radiographic osteoarthritis (OA), gender and age on these outcomes in patients with meniscectomy.

DESIGN

159 subjects (35 women), mean age 53 years, were examined 19 (17-22) years after open meniscectomy. Self-reported symptoms and function were assessed, performance tests were carried out and radiographs were taken. Sixty-eight age- and gender-matched controls were examined likewise. The data was analysed in two steps. First, subjects with meniscectomy were compared to the controls, and subgroup analyses were carried out with regard to radiographic OA, gender and age. Second, similar comparisons were carried out within the meniscectomized group.

RESULTS

Meniscectomized subjects reported significantly (P< 0.001) more symptoms and functional limitations than did controls. This was also true when operated subjects without OA were compared to controls without OA. Within the meniscectomized group, severe radiographic OA (joint space narrowing grade 2 or more) and female gender, but not older age, was associated with more symptoms and functional limitations. Meniscectomy was associated with worse muscular performance. Female gender and older age were associated with worse muscular performance in the study group.

CONCLUSIONS

Meniscectomy is associated with long-term symptoms and functional limitations, especially in women. Patients who had developed severe radiographic OA experienced more symptoms and functional limitations. Age did not influence self-reported outcomes, however older age was associated with worse muscular performance.

Radiographic stage of osteoarthritis or sex of the patient does not predict one year outcome after total hip arthroplasty

OBJECTIVE

To investigate whether patients with severe radiographic osteoarthritis (OA) have a different outcome at one year after total hip replacement than patients with moderate radiographic OA. To investigate sex related differences in preoperative radiographic and self reported status and in postoperative outcome.

METHODS

184 patients (96 women) with a mean age at surgery of 71.4 years (50-92), with primary OA of the hip were investigated preoperatively and six and 12 months postoperatively with two self administered questionnaires, SF-36 and WOMAC. The radiographs were evaluated by two independent radiologists using an atlas. Minimal joint space narrowing, osteophytes, cysts, sclerosis, and deformity were assessed. A summary grade 0-3 was made, based on joint space, where 3 is severe OA. The reference population for SF-36 consisted of 2901 subjects matched for age and sex from the general Swedish population.

RESULTS

162 patients fulfilled the study criteria. 113 had grade 3, 47 grade 2, and two grade 1 radiographic OA. There was no difference in preoperative or postoperative pain and physical impairment between patients with moderate and severe radiographic OA. There were no sex related differences in preoperative radiographic status, or in postoperative outcome. Neither were any differences in preoperative radiographic status of OA found in patients with previous total hip replacement of the contralateral hip, compared with those who had not been operated on before. All patients, regardless of preoperative radiographic OA stage, showed significant postoperative improvement and at one year achieved a health related quality of life similar to that of the reference group.

CONCLUSION

The severity of radiographic changes indicating OA often weighs heavily in the surgeon's decision to perform a total hip replacement. Yet, the findings of this study emphasise that the preoperative radiographic stage of OA has no correlation with the postoperative outcome after one year. Furthermore, this study failed to detect any sex related differences in preoperative radiographic and self reported status or in postoperative outcome of hip replacement.

Knee pain and osteoarthritis in older adults: a review of community burden and current use of primary health care

BACKGROUND

Osteoarthritis is the single most common cause of disability in older adults, and most patients with the condition will be managed in the community and primary care.

AIM

To discuss case definition of knee osteoarthritis for primary care and to summarise the burden of the condition in the community and related use of primary health care in the United Kingdom.

DESIGN

Narrative review.

METHOD

A literature search identified studies of incidence and prevalence of knee pain, disability, and radiographic osteoarthritis in the general population, and data related to primary care consultations. Findings from UK studies were summarised with reference to European and international studies.

RESULTS

During a one year period 25% of people over 55 years have a persistent episode of knee pain, of whom about one in six in the UK and the Netherlands consult their general practitioner about it in the same time period. The prevalence of painful disabling knee osteoarthritis in people over 55 years is 10%, of whom one quarter are severely disabled.

CONCLUSION

Knee osteoarthritis sufficiently severe to consider joint replacement represents a minority of all knee pain and disability suffered by older people. Healthcare provision in primary care needs to focus on this broader group to impact on community levels of pain and disability.

Factors associated with functional impairment in symptomatic knee osteoarthritis

OBJECTIVES

Knee osteoarthritis (OA) is a major cause of disability, particularly in the elderly. The factors determining disability remain unclear. The aim of this study was to assess the impact of clinical and psychosocial variables on function in knee OA and to develop models to account for observed variance in self-reported disability.

METHODS

The subjects (n = 69) were hospital out-patients. Self-reported disability was measured by the Western Ontario and McMaster Universities (WOMAC) OA index. Pain was measured by the WOMAC and the McGill pain questionnaire. Depression, anxiety, helplessness, self-efficacy, fatigue and quality of life were measured by standard instruments. A detailed knee examination, including pain threshold by dolorimetry, was performed. Radiographs were scored for individual features.

RESULTS

Pain severity, obesity and helplessness were the most important determinants of disability: a model including these variables accounted for 59.9% variance in WOMAC disability. Anxiety remained associated with disability in some models. Disability was unrelated to radiographic change.

CONCLUSIONS

Function in symptomatic knee OA is determined more by pain and obesity than by structural change, at least as seen on plain X-ray. Our study provides further support for interventions targeting anxiety and helplessness in knee OA.

The relationship of anxiety and depression with self-reported knee pain in the community: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To investigate the relationship between anxiety and depression and reporting of knee pain in the community.

METHODS

Subjects (n = 374) were community volunteers aged 40 years and above who are participants in the Baltimore Longitudinal Study of Aging, a prospective multidisciplinary research study of normative aging. Knee pain was defined by the First National Health and Nutrition Examination Survey question "have you ever had pain in or around your knee on most days for at least one month?"; anxiety and depression were measured by the relevant subscales of the Arthritis Impact Measurement Scales questionnaire. All subjects had standing anteroposterior radiographs, read for Kellgren and Lawrence (K + L) grade.

RESULTS

After adjustment for age, women reporting "ever" knee pain had significantly higher anxiety scores than those reporting "never" pain (3.06 +/- 0.26 versus 2.35 +/- 0.17; P = 0.025). Pain reporting was related neither to anxiety scores in men, nor to depression in either sex. Analysis stratified by radiographic severity, adjusted for age and gender, showed that differences in anxiety were confined to those reporting knee pain in the absence of radiographic change (i.e., K + L grade 0).

CONCLUSIONS

In the community, women reporting knee pain in the absence of radiographic osteoarthritis have higher anxiety scores than those without pain. Depression was not significantly related to knee pain in this population. Psychosocial factors may explain some of the discrepancy between reported knee pain and structural change as seen on x-ray.

Determinants of hip and knee flexion range: results from the San Antonio Longitudinal Study of Aging

OBJECTIVE

We analyzed data from the San Antonio Longitudinal Study of Aging, a neighborhood-based study of community-dwelling elderly people, to identify factors that determine the flexion range (FR) of hips and knees.

METHODS

The FR of hips and knees was measured in a cohort of 687 subjects aged 65 to 79 years. We used multivariate models to examine the associations among the FR of hips and knees, and between these and age, gender, ethnicity, body mass index (BMI), pain and its location, self-reported arthritis, and diabetes mellitus. The functional relevance of hip and knee FR was tested by measuring its association with 50-foot walking velocity.

RESULTS

More than 90 degrees of flexion in both hips and both knees was observed in 619 subjects (90.1%). Correlations among the FR of hips and knees ranged from 0.54 to 0.80 (P < 0.001 for Spearman r values). Multivariate analysis revealed a pattern of significant associations between each of the joints and its contralateral mate and ipsilateral partner joints that was consistent for both hips and both knees. Using each individual joint as the unit of analysis, the following variables were independently associated with hip or knee FR in multivariate models: rising BMI and female sex with reduced FR of both hips and knees, a Mexican American ethnic background with decreased hip FR, and knee pain with decreased knee FR. The functional importance of the FR of these two important joints was supported by its significant association with walking velocity in a model that adjusted for age, gender, ethnic background, BMI, and hip or knee pain.

CONCLUSIONS

Most community-dwelling elderly people have a FR of hips and knees that can be considered functional. The ipsilateral and contralateral hip or knee are significant independent determinants of the FR of each of these joints. Obesity, a health problem potentially amenable to preventive and therapeutic interventions, is a factor significantly associated with decreased FR of hips and knees.

The relationship between psychosocial variables and pain reporting in osteoarthritis of the knee

Psychosocial factors may explain some of the variation in pain reporting among individuals with knee OA. This has important potential implications for management; indeed, several studies (reviewed in ref. 56) have demonstrated that interventions may reduce knee pain without apparent halting or reversing of structural damage. Such interventions have included the simple provision of support by monthly telephone calls (57), self-management programs (58), and cognitive-behavioral approaches designed to teach patients ways of coping with their pain (59). These programs are even more effective if the spouse is involved (60). It should be noted that there may be a large placebo effect in these interventions, and the degree to which patients are responding simply to an interest being taken in them and their problems is unclear; at least one study has shown that formal cognitive-behavioral therapy is no better than didactic education at improving pain and function in knee OA (though both are beneficial) (61). Many studies examining the role of psychosocial factors have suffered from poor design; many, for example, fail to control for radiographic severity. Future studies should define how pain is identified (dichotomous, ever/never/current, severity), differentiate community and hospital subjects, and separate patients by type and location of OA. Studies should also control for other factors potentially associated with pain: obesity, comorbidity, muscle weakness, and aerobic fitness. Prospective studies would allow clarification of the cause and effect relationship between anxiety, depression, and pain, both in the community and in patients who have elected to seek medical help. In this way, we may increase our understanding of the complex interaction between mood, social factors, and pain reporting in knee OA and, thus, improve the effectiveness, already equivalent to many pharmacologic interventions, of treatments designed to address psychosocial factors.

Osteoarthritis in older adults

OBJECTIVE

This review highlights the clinical and pathophysiologic features of osteoarthritis (OA) of the peripheral joints and discusses the current and future management options for this common but potentially disabling disease. This article also addresses the contribution of osteoarthritis to falls and functional impairment in older people.

DESIGN

A critical assessment of current data regarding the pathogenesis of osteoarthritis, current and future therapies, and the potential role of OA in falls and functional impairment in older people.

CONCLUSIONS

Osteoarthritis is the most prevalent articular disease in older adults. Disease markers that will detect early disease and allow early intervention with pharmacologic agents that modify, if not halt, disease progression are much needed, but they are presently unavailable. Current management should include safe and adequate pain relief using systemic and local therapies and should also include medical and rehabilitative interventions to prevent, or at least compensate for, functional deficits. Although OA can result in impaired mobility and lower extremity function, its contribution as a cause of recurrent falls or impaired self-care, relative to other comorbid conditions, remains ill-defined. Further analysis of the determinants of disability, loss of mobility and falls in older patients with OA is needed.

Orthopedic pathology of the lower extremities: scintigraphic evaluation in the thigh, knee, and leg

Radionuclide imaging (RI) of the osseous and nonosseous structures of the thigh, knee, and leg provide important diagnostic and prognostic information upon which the orthopedic surgeon can base treatment planning and management decisions. 99mTc-MDP scintigraphy is essential in overuse injuries such as stress fractures and shin splints. RI is important in assessing complications of trauma. It is the only imaging modality able to assess the magnitude of physeal stimulus caused by femoral fractures and to predict a favorable or unfavorable outcome of leg length by semiquantitative analysis; SPECT imaging can detect and locate decreased metabolism associated with posttraumatic closure of the physeal plate to predict growth arrest and deformities. Three-phase bone imaging (TPBI) is essential to differentiate hypervascular from avascular nonunions and follow delayed union. In osteonecrosis of the knee, bone scintigraphy precedes radiography changes even in stage l of the disease. 99mTc-MDP and 99mTc-HIG imaging are powerful tools in determining the outcomes of osteoarthritis and rheumatoid arthritis, respectively. Bone scintigraphy can also detect chronic ligament and acute and chronic meniscal lesions. The combined use of TPBI, gallium-67 citrate imaging, and indium-111 or 99mTc-HMPAO labeled leukocytes is important to diagnose and differentiate acute from chronic osteomyelitis, and to detect infected knee prostheses. Thallium-201 chloride imaging and 99mTc-sestamibi imaging have an important role in the assessment of tumor response to chemotherapy and in the quantification of tumor viability.

Pathogenesis and treatment of osteoarthritis

OA represents the final common pathway of a number of pathologic processes. The challenge is to define and classify the subsets of OA to understand the causes and to devise specific therapies. Effective chondroprotective therapies will be most useful when applied to high-risk individuals before the emergence of symptomatic OA. This will be feasible only with an improved understanding of the complex interaction of genes and environment in the OA disease process. Moreover, identifying the heritable bases of this disease will provide insight into the molecular mechanisms of the complex pathway that results in OA. Clinicians who encounter and treat OA patients can look forward to the development of more effective and innovative therapies based on a rapidly improving understanding of OA.

Quantitative radiography in osteoarthritis: analysis

This article has reviewed the use of semiquantitative individual feature scales based on standard photographs in published atlases, and quantitative techniques, including chondrometry, high-definition microfocal radiography, and computerized digital image analysis, and commented on their use in longitudinal studies of osteoarthritis where data are obtained from the reading of serial radiographs. For investigators planning future studies involving the reading of already available radiographs, the use of computerized digital image analysis, if available, is recommended for measurement of joint space because of its superior reliability; if this is not available, then chondrometry should be used. Other individual features should be scored using a standard atlas. For investigators planning new studies, especially therapeutic trials, recent guidelines recommended by a World Health Organization Satellite Workshop on 'The standardization of methods for the assessment of articular cartilage changes in osteoarthritis of the knee and hip joint' should be followed (Dieppe, 1995).