Multicenter Osteoarthritis Study Research Articles

The association between patella alta and structural features of osteoarthritis on MRI: The Multicenter Osteoarthritis (MOST) Study

Patella alta (PA) is present when the patella position is high relative to the femoral trochlea, and is a known risk factor for patellar dislocation and anterior knee pain in young persons. PA is defined as present when the Insall‐Salvati ratio (ISR), length of the patellar tendon (LT) divided by length of the patella (LP), is = 1.2. The purpose of this study was to determine, in middle aged and older persons at risk for knee osteoarthritis, the association between PA and patellofemoral joint (PFJ) cartilage morphology and bone marrow lesions (BMLs). We measured the ISR on the lateral radiograph in 443 subjects from a cohort study of persons aged 50‐79 years. Cartilage morphology and BMLs were graded on MRI using a semi‐quantitative scale (0‐6, 0‐3 respectively, with 0 representing absence of pathology) in the medial and lateral PFJ. Using logistic regression, we determined the association between the ISR and cartilage morphology and BMLs, adjusting for age, sex, and BMI. The mean ISR was 1.095 and 113 subjects' (26%) ISR was = 1.2. Compared with subjects who did not have PA, those with PA had 1.82 (95% CI 1.26, 2.63) and 2.38 (1.59, 3.58) times the odds of lateral PFJ cartilage damage and BMLs, respectively. We are currently investigating the biomechanical mechanism for the changes seen in bone and cartilage in subjects with PA. This research was supported by the NIH and Arthritis Foundation.Grant Funding SourceNIH and Arthritis Foundation

Is obesity a risk factor for progressive radiographic knee osteoarthritis?

To examine whether obesity increases the risk of progression of knee osteoarthritis (OA). We used data from the Multicenter Osteoarthritis Study, a longitudinal study of persons with or at high risk of knee OA. OA was characterized at baseline and 30 months using posteroanterior fixed-flexion radiographs and Kellgren/Lawrence (K/L) grading, with alignment assessed on full-extremity films. In knees with OA at baseline (K/L grade 2 or 3), progression was defined as tibiofemoral joint space narrowing on the 30-month radiograph. In knees without OA at baseline (K/L grade 0 or 1), incident OA was defined as the development of radiographic OA at 30 months. Body mass index (BMI) at baseline was classified as normal (<25 kg/m(2)), overweight (25-<30 kg/m(2)), obese (30-<35 kg/m(2)), and very obese (>or=35 kg/m(2)). The risk of progression was tested in all knees and in subgroups categorized according to alignment. Analyses were adjusted for age, sex, knee injury, and bone density. Among the 2,623 subjects (5,159 knees), 60% were women, and the mean +/- SD age was 62.4 +/- 8.0 years. More than 80% of subjects were overweight or obese. At baseline, 36.4% of knees had tibiofemoral OA, and of those, only one-third were neutrally aligned. Compared with subjects with a normal BMI, those who were obese or very obese were at an increased risk of incident OA (relative risk 2.4 and 3.2, respectively [P for trend < 0.001]); this risk extended to knees from all alignment groups. Among knees with OA at baseline, there was no overall association between a high BMI and the risk of OA progression; however, an increased risk of progression was observed among knees with neutral but not varus alignment. The effect of obesity was intermediate in those with valgus alignment. Although obesity was a risk factor for incident knee OA, we observed no overall relationship between obesity and the progression of knee OA. Obesity was not associated with OA progression in knees with varus alignment; however, it did increase the risk of progression in knees with neutral or valgus alignment. Therefore, weight loss may not be effective in preventing progression of structural damage in OA knees with varus alignment.

Meniscal tear in knees without surgery and the development of radiographic osteoarthritis among middle‐aged and elderly persons: The multicenter osteoarthritis study

Although partial meniscectomy is a risk factor for the development of knee osteoarthritis (OA), there is a lack of evidence that meniscal damage that is not treated with surgery would also lead to OA, suggesting that surgery itself may cause joint damage. Furthermore, meniscal damage is common. The aim of this study was to evaluate the association between meniscal damage in knees without surgery and the development of radiographic tibiofemoral OA. We conducted a prospective case-control study nested within the observational Multicenter Osteoarthritis Study, which included a sample of men and women ages 50-79 years at high risk of knee OA who were recruited from the community. Patients who had no baseline radiographic knee OA but in whom tibiofemoral OA developed during the 30-month followup period were cases (n = 121). Control subjects (n = 294) were drawn randomly from the same source population as cases but had no knee OA after 30 months of followup. Individuals whose knees had previously undergone surgery were excluded. Meniscal damage was defined as the presence of any medial or lateral meniscal tearing, maceration, or destruction. Meniscal damage at baseline was more common in case knees than in control knees (54% versus 18%; P < 0.001). The model comparing any meniscal damage with no meniscal damage (adjusted for baseline age, sex, body mass index, physical activity, and mechanical knee alignment) yielded an odds ratio of 5.7 (95% confidence interval 3.4-9.4). In knees without surgery, meniscal damage is a potent risk factor for the development of radiographic OA. These results highlight the need for better understanding, prevention, and treatment of meniscal damage.

Meniscus—Friend or foe: Epidemiologic observations and surgical implications

Meniscus—Friend or foe: Epidemiologic observations and surgical implications

Leg-length inequality is not associated with greater trochanteric pain syndrome

IntroductionGreater trochanteric pain syndrome (GTPS) is a common condition, the pathogenesis of which is incompletely understood. Although leg-length inequality has been suggested as a potential risk factor for GTPS, this widely held assumption has not been tested.MethodsA cross-sectional analysis of greater trochanteric tenderness to palpation was performed in subjects with complaints of hip pain and no signs of hip osteoarthritis or generalized myofascial tenderness. Subjects were recruited from one clinical center of the Multicenter Osteoarthritis Study, a multicenter population-based study of community-dwelling adults aged 50 to 79 years. Diagnosis of GTPS was based on a standardized physical examination performed by trained examiners, and technicians measured leg length on full-limb anteroposterior radiographs.ResultsA total of 1,482 subjects were eligible for analysis of GTPS and leg length. Subjects' mean ± standard deviation age was 62.4 ± 8.2 years, and 59.8% were female. A total of 372 lower limbs from 271 subjects met the definition for having GTPS. Leg-length inequality (difference ≥ 1 cm) was present in 37 subjects with GTPS and in 163 subjects without GTPS (P = 0.86). Using a variety of definitions of leg-length inequality, including categorical and continuous measures, there was no association of this parameter with the occurrence of GTPS (for example, for ≥ 1 cm leg-length inequality, odds ratio = 1.17 (95% confidence interval = 0.79 to 1.73)). In adjusted analyses, female sex was significantly associated with the presence of GTPS, with an adjusted odds ratio of 3.04 (95% confidence interval = 2.07 to 4.47).ConclusionThe present study found no evidence to support an association between leg-length inequality and greater trochanteric pain syndrome.

Effect of meniscal damage on the development of frequent knee pain, aching, or stiffness

To evaluate the effect of meniscal damage on the development of frequent knee pain, aching, or stiffness in middle-aged and older adults. The Multicenter Osteoarthritis Study is a prospective study of 3,026 individuals 50 years of age or older who have or are at high risk of developing knee osteoarthritis (OA). We investigated knees at baseline and at 15 months. Case knees (n = 110) were those with no pain, aching, or stiffness on most days at baseline, but that had developed frequent pain, aching, or stiffness at 15 months. Control knees (n = 220) were drawn randomly from knees with no frequent symptoms at baseline that did not become case knees. Using 1.0T magnetic resonance imaging performed at baseline and at followup, 2 musculoskeletal radiologists blinded to the case-control status assessed the meniscal damage using the following scale: 0 = intact, 1 = minor tear, 2 = nondisplaced tear or prior surgical repair, and 3 = displaced tear, resection, maceration, or destruction. The effect of meniscal damage was analyzed by contingency tables and logistic regression. Meniscal damage was common at baseline both in case knees (38%) and in control knees (29%). Although there was a modest association between the meniscal damage score (range 0-3) and the development of frequent knee pain, aching, or stiffness (odds ratio [OR] 1.21, 95% confidence interval [95% CI] 0.96-1.51, adjusted for age, sex, and body mass index), meniscal damage was mostly present in knees with OA. When considering the co-occurrence of OA, we found no independent association between meniscal damage and the development of frequent knee symptoms (OR 1.05, 95% CI 0.80-1.37). In middle-aged and older adults, any association between meniscal damage and the development of frequent knee pain seems to be present because both pain and meniscal damage are related to OA and not because of a direct link between the two.

Greater Trochanteric Pain Syndrome: Epidemiology and Associated Factors

Segal NA, Felson DT, Torner JC, Zhu Y, Curtis JR, Niu J, Nevitt MC, for the Multicenter Osteoarthritis (MOST) Study Group. Greater trochanteric pain syndrome: epidemiology and associated features. Objectives To describe the prevalence of greater trochanteric pain syndrome (GTPS); to determine whether GTPS is associated with iliotibial band (ITB) tenderness, knee osteoarthritis (OA), body mass index (BMI), or low back pain (LBP); and to assess whether GTPS is associated with reduced hip internal rotation, physical activity, and mobility. Design Cross-sectional, population-based study. Setting Multicenter observational study. Participants Community-dwelling adults (N=3026) ages 50 to 79 years. Interventions Not applicable. Main Outcome Measures Greater trochanteric tenderness to palpation in subjects with complaints of hip pain and no signs of hip OA or generalized myofascial tenderness. Results The prevalence of unilateral and bilateral GTPS was 15.0% and 8.5% in women and 6.6% and 1.9% men. Odds ratio (OR) for women was 3.37 (95% confidence interval [CI], 2.67−4.25), but age and race were not significantly associated with GTPS. In a multivariate model, adjusting for age, sex, ITB tenderness, ipsilateral and contralateral knee OA, BMI, and LBP, ITB tenderness (OR=1.72; 95% CI, 1.34−2.19), knee OA ipsilaterally (OR=3.47; 95% CI, 2.72−4.42) and contralaterally (OR=1.74; 95% CI, 1.32−2.28), and LBP (OR=2.79; 95% CI, 2.22−3.50) were positively related to GTPS. In this complete model, BMI was not associated with GTPS (OR=1.10; 95% CI, 0.80−1.52 when comparing ≥ 30 with <25kg/m 2). Hip internal rotation range of motion did not differ based on GTPS status. After multivariate adjustment, GTPS did not alter physical activity score, but bilateal GTPS was significantly associated with a higher 20-meter walk time and chair stand time. Conclusions The higher prevalence of GTPS in women and in adults with ITB pain or knee OA indicates that altered lower-limb biomechanics may be related to GTPS. Slower functional performance in those with GTPS suggests that the study of targeted rehabilitation may be useful. A longitudinal study will be necessary to identify causal factors and outcomes of interventions.

Bone-on-bone forces at the knee joint during walking and stairclimbing

To determine what MRI-detectable osteoarthritis features that are not visualized on radiography demonstrate progression longitudinally in Kellgren and Lawrence (KL) grade 4 knees.We studied subjects from the Multicenter Osteoarthritis Study who had KL grade 4 knees at baseline and had baseline and 30-month MRI. Cartilage damage, bone marrow lesions (BMLs), meniscal damage, synovitis (signal changes in Hoffa fat pad), and effusion (fluid equivalent signal in the joint cavity) were semiquantitatively scored using the Whole Organ MRI Score (WORMS) system in five subregions of the medial and lateral tibiofemoral (TF) compartments. Analysis was performed for the compartment showing bone-on-bone appearance (“index”) on radiograph and also for the other TF compartment of the same knee. Synovitis and effusion were assessed for the whole knee. Changes in scores at follow-up were noted for each feature. For cartilage and BML, within-grade changes were also recorded.140 subjects (164 knees) were included (50% women, mean age 66.0 ± 8.6 years, mean BMI 30.4 ± 5.1 kg/m2). Longitudinally, 51 index compartments (34%) showed an increase in the sum of cartilage scores from all subregions. In the other compartment, 25% showed an increase in the sum score for cartilage damage. For BMLs in the index compartment, 50 knees (33%) showed an increase in maximum score and 32 (21%) showed a decrease. Meniscal status mostly remained stable. Effusion worsened in 36 knees (25%) and improved in 13 knees (9%). Synovitis worsened in 14 knees (10%) and improved in six knees (4%).In KL grade 4 knees, MRI-detected cartilage loss and fluctuation of BMLs, effusion, and synovitis occurred frequently over a 30-month period.