Steven A. Mazzuca

Quadriceps Weakness and Osteoarthritis of the Knee

Osteoarthritis of the knee is the most common cause of chronic disability among older persons in the United States [1]. In persons with symptomatic osteoarthritis of the knee, quadriceps muscle weakness is common and is widely believed to result from disuse atrophy secondary to joint pain. Although exercises to strengthen the quadriceps may relieve joint pain in persons with osteoarthritis of the knee [2-6], the role of periarticular muscle weakness in the pathogenesis of joint pain and disability in these persons is poorly understood. The basis for the beneficial effect of strengthening exercises is unclear, and the duration of the improvement has not been studied. Furthermore, the possibility that muscle weakness is an etiologic factor underlying the pathologic changes of osteoarthritis has seldom been considered. Elucidation of the role of muscle weakness in osteoarthritis is particularly important given our growing understanding of safe and effective methods for increasing strength in elderly persons [7, 8]. A substantial proportion of persons who have radiographic evidence of osteoarthritis of the knee have no joint pain [9]. Because asymptomatic persons with radiographic changes seldom seek medical attention for osteoarthritis, muscle weakness has not been studied previously in this group. Thus, it is not known whether quadriceps weakness precedes or follows joint pain or (if it follows joint pain) whether it is mediated by disuse atrophy or by physiologic mechanisms that may inhibit muscle contraction [10]. To address this issue, we studied the relation among lower-extremity muscle strength, lower-extremity lean tissue mass, and osteoarthritis of the knee in men and women 65 years of age and older. Methods Study Group To obtain a sample of elderly persons living in the community, we conducted brief telephone interviews with residents of households in central Indiana. Potential participants were selected through modified random-digit dialing to increase the sampled proportion of persons 65 years of age and older. Persons were eligible if they met the minimal criteria for participation: They were willing and able to provide informed consent and to undergo the necessary strength assessments and other evaluations. Persons were excluded if they had had amputations of both lower extremities, had undergone total knee arthroplasty, or had recently had a cerebrovascular accident or myocardial infarction. A total of 462 persons (approximately 55% of all who were eligible) agreed to participate and completed the following evaluations. Evaluations Radiography of the Knee Standing anteroposterior and lateral radiographs of both knees of each study participant were obtained, and the severity of osteoarthritis in the tibiofemoral compartment was graded by a musculoskeletal radiologist according to the criteria of Kellgren and Lawrence. Similar criteria, based on the presence of osteophytes and joint space narrowing, were used for the patellofemoral compartment [11]. The radiologist was blinded to the clinical status and characteristics of all patients. A participant had to have a Kellgren and Lawrence grade of 2 or more in either knee to be classified as having osteoarthritis. Knee Pain and Function The Western Ontario and McMaster Universities Arthritis Index was used to evaluate knee pain and function [12]. This index assesses the severity of knee pain during 5 activities or situations (walking on a flat surface, going up or down stairs, at night while in bed, sitting or lying, and standing upright) and the severity of impairment of lower-extremity function during 17 activities. Pain and functional impairment were assessed in each knee separately. Responses to each question about the severity of knee pain and level of impairment were recorded on a categorical scale as none, mild, moderate, severe, or extreme. Each category was assigned a corresponding numeric score from 1 to 5 (5 = extreme). Hence, the range on the pain scale was 5 to 25 and the range on the physical impairment scale was 17 to 85 (85 = greatest functional limitation). For the purposes of analysis, participants who rated the severity of their knee pain as moderate or greater (3) with any of the 5 activities on more than half of the days in the month preceding the evaluation were considered to have knee pain. Thus, pain in the more distant past that had resolved was not included. Participants were also questioned about current and previous regular (5 times per week) or occasional use of over-the-counter and prescription analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) in the past year. Lower-Extremity Muscle Strength The strength of each leg was evaluated by using an isokinetic dynamometer (KIN-COM 500H, Chattecx Corp., Hixson, Tennessee). Peak torque was recorded in both the concentric (contractions during muscle shortening) and eccentric (contractions during muscle lengthening) modes. Participants were allowed several submaximal or maximal practice efforts to familiarize themselves with the operation of the dynamometer. Once formal testing began, the best of three maximal efforts was recorded for flexion and extension at both 60 degrees per second and 120 degrees per second. Aborted efforts were repeated in order to obtain the best possible representation of strength for each participant. Concentric and eccentric testing yielded similar results, but because of greater variability in eccentric testing, only the concentric test results are shown. Lower-Extremity Lean Tissue Mass Total-body dual-energy x-ray absorptiometry was done in all participants by using a Lunar-DPX-L instrument (Lunar Corp., Madison, Wisconsin). Results were analyzed for total and regional body composition, including body fat, mineral, and lean components (lean components were components other than fat or mineral). The right and left lower extremities were analyzed separately. The lower extremity was defined as all tissue below a diagonal line drawn outward and upward from the groin area through the femoral neck. Statistical Analysis Participants were divided into four groups on the basis of presence or absence of radiographic evidence of osteoarthritis of the knee and presence or absence of knee pain, as defined above. Men and women were compared by using the t-test. Comparisons of Arthritis Index pain and functional impairment scores were done by using nonparametric approaches. For analyses of continuous data involving more than two groups of participants (for example, osteoarthritis with or without knee pain), analysis of variance was used to determine whether an overall difference was present. The Fisher protected least-significant-difference procedure was used for pairwise comparisons. Comparisons within participants (for example, comparison of the two legs in a person with unilateral osteoarthritis of the knee) were done by using paired t-tests. Regression models were constructed with the generalized estimating equations approach of Zeger and Liang [13]. This approach inflates the standard errors to adjust for correlations in both independent variables (such as strength) and dependent variables (such as radiographic grade) within participants. Statistically significant differences (P < 0.05) in the above analyses are specifically noted below. Results The characteristics of the 462 men and women in the cohort are shown in Table 1. As expected, men were taller, were heavier, and had greater lower-extremity strength and lean tissue mass in the lower extremities compared with women (P < 0.001 for all comparisons). Table 1. Age, Height, Weight, and Lower-Extremity Strength and Lean Tissue Mass* One hundred forty-five participants (31%; 33% of the women and 30% of the men) had radiographic evidence of osteoarthritis involving the tibiofemoral compartment, the patellofemoral compartment, or both. In 62 participants (43%), the radiographic changes were unilateral. Table 2 shows the association between osteoarthritis and obesity [14-16]. Women in the cohort who had osteoarthritis were approximately 15% heavier than women with normal radiographs and no knee pain. Men with osteoarthritis were also slightly heavier than men without osteoarthritis. Table 2. Body Weight and Summed Arthritis Index Scores for Recent Pain and Function in the Left Knee in Participants with and without Radiographic Evidence of Osteoarthritis* Among those with radiographic evidence of tibiofemoral osteoarthritis, women were slightly more likely than men to report knee pain (P = 0.10; Table 3). Table 3. Radiography and Recent Pain in the Left Knee Table 2 also shows the mean summed and the distribution of scores for left knee pain and functional impairment (data for the right knee were similar). Among men and women with radiographic evidence of osteoarthritis who reported having knee pain, the mean summed pain score for the knee with osteoarthritis was approximately 12 (median score, 2 of 5). In comparison, the mean pain score of participants who reported knee pain but did not have radiographic evidence of osteoarthritis in the painful knee was approximately 10 (median score, 2 of 5)-only slightly lower than the mean pain score of participants with radiographic changes. Consistent with their relatively low pain scores, these community-dwelling participants with osteoarthritis reported moderately low use of NSAIDs (Table 4). Table 4. Participants Reporting Regular Current or Previous Use of Analgesics and Nonsteroidal Anti-inflammatory Drugs Related to the Presence of Radiographic Evidence of Osteoarthritis of the Knee and Recent Knee Pain* Arthritis Index scores for functional impairment paralleled those for pain (Table 2). Participants with osteoarthritis had the greatest functional impairment (P < 0.001 for the comparison with patients who did not have pain or radiographic evidence of osteoarthritis). Functional impairment in participants who had pain but no radiographic evidence of osteoarthrit

Reduced quadriceps strength relative to body weight: A risk factor for knee osteoarthritis in women?

OBJECTIVE To determine whether baseline lower extremity muscle weakness is a risk factor for incident radiographic osteoarthritis (OA) of the knee. METHODS This prospective study involved 342 elderly community-dwelling subjects (178 women, 164 men) from central Indiana, for whom baseline and followup (mean interval 31.3 months) knee radiographs were available. Lower extremity muscle strength was measured by isokinetic dynamometry and lean tissue (i.e., muscle) mass in the lower extremities by dual x-ray absorptiometry. RESULTS Knee OA was associated with an increase in body weight in women (P = 0.0014), but not in men. In both sexes, lower extremity muscle mass exhibited a strong positive correlation with body weight. In women, after adjustment for body weight, knee extensor strength was 18% lower at baseline among subjects who developed incident knee OA than among the controls (P = 0.053), whereas after adjustment for lower extremity muscle mass, knee extensor strength was 15% lower than in the controls (P not significant). In men, in contrast, adjusted knee extensor strength at baseline was comparable to that in the controls. Among the 13 women who developed incident OA, there was a strong, highly significant negative correlation between body weight and extensor strength (r = -0.740, P = 0.003), that is, the more obese the subject, the greater the reduction of quadriceps strength. In contrast, among the 14 men who developed incident OA, a modest positive correlation existed between weight and quadriceps strength (r = 0.455, P = 0.058). No correlation between knee flexor (hamstring) strength and knee OA was seen in either sex. CONCLUSION Reduced quadriceps strength relative to body weight may be a risk factor for knee OA in women.

DOES PATIENT EDUCATION IN CHRONIC DISEASE HAVE THERAPEUTIC VALUE

A pool of 320 articles on patient education were screened to select controlled experiments in chronic disease where the dependent variables included (a) compliance with therapeutic regimen, (b) physiological progress of patients or (c) long-range outcome. Thirty such articles were found; and the magnitude of experimental effects of patient education were calculated using an empirical form of integrating research findings known as meta-analysis. Summary of all experimental effects showed patient education most successful in altering compliance (average improvement = 0.67 sigma over control, p less than 0.05). However, average improvements in physiological progress (0.49 sigma) and health outcome (0.02 sigma) were also statistically significant (p less than 0.01 and p less than 0.05, respectively). Efforts to improve health by increasing patient knowledge alone were rarely successful. Behaviorally-oriented program, often with special attention to changing the environment in which patients care for themselves, were consistently more successful at improving the clinical course of chronic disease.

The Diabetes Education Study: A Controlled Trial of the Effects of Diabetes Patient Education

The Diabetes Education Study (DIABEDS) was a randomized, controlled trial of the effects of patient and physician education. This article describes a systematic education program for diabetes patients and its effects on patient knowledge, skills, self-care behaviors, and relevant physiologic outcomes. The original sample consisted of 532 diabetes patients from the general medicine clinic at an urban medical center. Patients were predominantly elderly, black women with non-insulin-dependent diabetes mellitus of long duration. Patients randomly assigned to experimental groups (N = 263) were offered up to seven modules of patient education. Each content area module contained didactic instruction (lecture, discussion, audio-visual presentation), skill exercises (demonstration, practice, feedback), and behavioral modification techniques (goal setting, contracting, regular follow-up). Two hundred seventy-five patients remained in the study throughout baseline, intervention, and postintervention periods (August 1978 to July 1982). Despite the requirement that patients demonstrate mastery of educational objectives for each module, postintervention assessment 11–14 mo after instruction showed only rare differences between experimental and control patients in diabetes knowledge. However, statistically significant group differences in self-care skills and compliance behaviors were relatively more numerous. Experimental group patients experienced significantly greater reductions in fasting blood glucose (−27.5 mg/dl versus −2.8 mg/dl, P < 0.05) and glycosylated hemoglobin (−0.43% versus + 0.35%, P < 0.05) as compared with control subjects. Patient education also had similar effects on body weight, blood pressure, and serum creatinine. Continued follow-up is planned for DIABEDS patients to determine the longevity of effects and subsequent impact on emergency room visits and hospitalization.

A Comprehensive Care Management Program to Prevent Chronic Obstructive Pulmonary Disease Hospitalizations: A Randomized, Controlled Trial

BACKGROUND Improving a patients ability to self-monitor and manage changes in chronic obstructive pulmonary disease (COPD) symptoms may improve outcomes. OBJECTIVE To determine the efficacy of a comprehensive care management program (CCMP) in reducing the risk for COPD hospitalization. DESIGN A randomized, controlled trial comparing CCMP with guideline-based usual care. (ClinicalTrials.gov registration number: NCT00395083) SETTING: 20 Veterans Affairs hospital-based outpatient clinics. PARTICIPANTS Patients hospitalized for COPD in the past year. INTERVENTION The CCMP included COPD education during 4 individual sessions and 1 group session, an action plan for identification and treatment of exacerbations, and scheduled proactive telephone calls for case management. Patients in both the intervention and usual care groups received a COPD informational booklet; their primary care providers received a copy of COPD guidelines and were advised to manage their patients according to these guidelines. Patients were randomly assigned, stratifying by site based on random, permuted blocks of variable size. MEASUREMENTS The primary outcome was time to first COPD hospitalization. Staff blinded to study group performed telephone-based assessment of COPD exacerbations and hospitalizations, and all hospitalizations were blindly adjudicated. Secondary outcomes included non-COPD health care use, all-cause mortality, health-related quality of life, patient satisfaction, disease knowledge, and self-efficacy. RESULTS Of the eligible patients, 209 were randomly assigned to the intervention group and 217 to the usual care group. Citing serious safety concerns, the data monitoring committee terminated the intervention before the trials planned completion after 426 (44%) of the planned total of 960 patients were enrolled. Mean follow-up was 250 days. When the study was stopped, the 1-year cumulative incidence of COPD-related hospitalization was 27% in the intervention group and 24% in the usual care group (hazard ratio, 1.13 [95% CI, 0.70 to 1.80]; P= 0.62). There were 28 deaths from all causes in the intervention group versus 10 in the usual care group (hazard ratio, 3.00 [CI, 1.46 to 6.17]; P= 0.003). Cause could be assigned in 27 (71%) deaths. Deaths due to COPD accounted for the largest difference: 10 in the intervention group versus 3 in the usual care group (hazard ratio, 3.60 [CI, 0.99 to 13.08]; P= 0.053). LIMITATIONS Available data could not fully explain the excess mortality in the intervention group. Ability to assess the quality of the educational sessions provided by the case managers was limited. CONCLUSION A CCMP in patients with severe COPD had not decreased COPD-related hospitalizations when the trial was stopped prematurely. The CCMP was associated with unanticipated excess mortality, results that differ markedly from similar previous trials. A data monitoring committee should be considered in the design of clinical trials involving behavioral interventions.

Effect of alignment of the medial tibial plateau and x-ray beam on apparent progression of osteoarthritis in the standing anteroposterior knee radiograph

OBJECTIVE Previous studies of knee osteoarthritis (OA) have yielded variable estimates of the rate of joint space narrowing (JSN) in the standing anteroposterior (AP) radiograph, due largely to longitudinal changes in the alignment of the medial tibial plateau (MTP) and x-ray beam. To characterize this bias, we examined serial radiographs of subjects with knee OA in population-based and clinical OA cohorts from 3 locations in the United States and the United Kingdom. METHODS Radiographic features of knee OA (e.g., osteophytosis, JSN) and MTP alignment in 428 OA knees were evaluated by consensus of 2 readers. Alignment was considered satisfactory if the anterior and posterior margins of the MTP were superimposed within 1 mm. Readers were blinded to subject identity, and films were read in random order. The minimum medial joint space width was also measured manually (standard error of repeated measurements 0.20 mm) in serial knee images. RESULTS Only 14% of serial radiographs exhibited alignment of the MTP in both images. In OA knees with satisfactory alignment in both images, the mean rate of JSN over 2-3 years (0.26 mm/year) was significantly larger (P = 0.004) than that in OA knees with misalignment in 1 or both radiographs and was 86% more rapid than the mean JSN in all OA knees. Moreover, the within-group standard deviation of JSN was significantly smaller among knees with reproduced alignment of the MTP than in knees in which misalignment occurred in 1 or both images (P = 0.006). CONCLUSION Poor standardization of knee positioning in serial standing AP radiographs in previous studies of OA progression has obscured the rate and variability of articular cartilage loss in subjects with knee OA. True JSN (i.e., JSN that is not attributable to longitudinal changes in the alignment of the MTP with the x-ray beam in serial radiographic examinations) may occur more rapidly, and with less between-subject variability, than that previously thought to be characteristic of knee OA.

Change in regional cartilage morphology and joint space width in osteoarthritis participants versus healthy controls: a multicentre study using 3.0 Tesla MRI and Lyon–Schuss radiography

Objective: Cartilage morphology displays sensitivity to change in osteoarthritis (OA) with quantitative MRI (qMRI). However, (sub)regional cartilage thickness change at 3.0 Tesla (T) has not been directly compared with radiographic progression of joint space narrowing in OA participants and non-arthritic controls. Methods: A total of 145 women were imaged at 7 clinical centres: 86 were non-obese and asymptomatic without radiographic OA and 55 were obese with symptomatic and radiographic OA (27 Kellgren–Lawrence grade (KLG)2 and 28 KLG3). Lyon–Schuss (LS) and fixed flexion (FF) radiographs were obtained at baseline, 12 and 24 months, and coronal spoiled gradient echo MRI sequences at 3.0 T at baseline, 6, 12 and 24 months. (Sub)regional, femorotibial cartilage thickness and minimum joint space width (mJSW) in the medial femorotibial compartment were measured and the standardised response means (SRMs) determined. Results: At 6 months, qMRI demonstrated a −3.7% “annualised” change in cartilage thickness (SRM −0.33) in the central medial femorotibial compartment (cMFTC) of KLG3 subjects, but no change in KLG2 subjects. The SRM for mJSW in 12-month LS/FF radiographs of KLG3 participants was −0.68/−0.13 and at 24 months was −0.62/−0.20. The SRM for cMFTC changes measured with qMRI was −0.32 (12 months; −2.0%) and −0.48 (24 months; −2.2%), respectively. Conclusions: qMRI and LS radiography detected significant change in KLG3 participants at high risk of progression, but not in KLG2 participants, and only small changes in controls. At 12 and 24 months, LS displayed greater, and FF less, sensitivity to change in KLG3 participants than qMRI.

Reduced utilization and cost of primary care clinic visits resulting from self-care education for patients with osteoarthritis of the knee

OBJECTIVE To determine the extent to which the cost of an effective self-care intervention for primary care patients with knee osteoarthritis (OA) was offset by savings resulting from reduced utilization of ambulatory medical services. METHODS In an attention-controlled clinical trial, 211 patients with knee OA from the general medicine clinic of a municipal hospital were assigned arbitrarily to conditions of self-care education (group E) or attention control (group AC). Group E (n = 105) received individualized instruction and followup emphasizing nonpharmacologic management of joint pain. Group AC (n = 106) received a standard public education presentation and attention-controlling followup. A comprehensive clinical database provided data concerning utilization and cost of health services during the following year. RESULTS Only 25 subjects (12%) were lost to followup. The 94 subjects remaining in group E made 528 primary care visits during the year following intervention, compared with 616 visits by the 92 patients remaining in group AC (median visits 5 versus 6, respectively; P < 0.05). Fewer visits translated directly into reduced clinic costs in group E, relative to controls (median costs [1996 dollars]

OARSI/OMERACT Initiative to Define States of Severity and Indication for Joint Replacement in Hip and Knee Osteoarthritis. An OMERACT 10 Special Interest Group

229 versus

Field test of the reproducibility of the semiflexed metatarsophalangeal view in repeated radiographic examinations of subjects with osteoarthritis of the knee

305, respectively; P < 0.05). However, self-care education had no significant effects on utilization and costs of outpatient pharmacy, laboratory, or radiology services over the ensuing year. The cost per patient to deliver the self-care intervention was estimated to be