New developments in osteoarthritis. Prevention of injury-related knee osteoarthritis: opportunities for the primary and secondary prevention of knee osteoarthritis

Where risk factors have been identified in knee and hip osteoarthritis (OA), with few exceptions, no prevention strategies have proven beneficial. The major risk factors for knee OA are advanced age, injury and obesity. However, there is limited or no evidence that they are modifiable or to what degree modifying them is effective in preventing development of knee OA or in preventing symptoms and progressive disease in persons with early OA. The notable exception is the growing epidemic of (sports) injury related knee OA. This review details the biological and clinical data indicating the efficacy of interventions targeting neuromuscular and biomechanical factors that make this subset of OA an attractive public health target, and highlights research opportunities for the future

Is Lifelong Knee Joint Force from Work, Home, and Sport Related to Knee Osteoarthritis?

Purpose. To investigate the association of cumulative lifetime knee joint force on the risk of self-reported medically-diagnosed knee osteoarthritis (OA). Methods. Exposure data on lifetime physical activity type (occupational, household, sport/recreation) and dose (frequency, intensity, duration) were collected from 4,269 Canadian men and women as part of the Physical Activity and Joint Heath cohort study. Subjects were ranked in terms of the “cumulative peak force index”, a measure of lifetime mechanical knee force. Multivariable logistic regression was conducted to obtain adjusted effects for mean lifetime knee force on the risk of knee OA. Results. High levels of total lifetime, occupational and household-related force were associated with an increased in risk of OA, with odds ratio’s ranging from approximately 1.3 to 2. Joint injury, high BMI and older age were related to risk of knee OA, consistent with previous studies. Conclusions. A newly developed measure of lifetime mechanical knee force from physical activity was employed to estimate the risk of self-reported, medically-diagnosed knee OA. While there are limitations, this paper suggests that high levels of total lifetime force (all domains combined), and occupational force in men and household force in women were risk factors for knee OA

Clinical findings in patellofemoral osteoarthritis compared to individually-matched controls: A pilot study

Objective To explore clinical characteristics in individuals with patellofemoral osteoarthritis (PFOA) compared to individually-matched asymptomatic controls. We also explored associations between functional performance and patient-reported symptoms with patellofemoral alignment. Methods We assessed 15 individuals with PFOA and 15 individually-matched asymptomatic controls. In addition to physical examination and patient-reported questionnaires, we evaluated functional performance, lower extremity strength and range of motion, and patellar alignment (using MRI). We analysed group differences with Wilcoxon's matched-pairs signed rank tests, and within-group associations with Spearman's rank correlations. Results We included 24 (80%) women with median (IQR) age of 56 (9) years and BMI of 22.8 (5.9) kg/m 2. Individuals with PFOA reported lower quality of life (8/100 points lower EQ-5D-5L, p=0.02), and performed worse on two functional tests: repeated one-leg rises (median 16 fewer rises, p=0.04) and timed stair climb (1.2 s slower, p=0.03). There were no differences in strength tests performed or range of motion. Patellar proximal translation correlated with worse functional performance and worse patient-reported pain, function and self-efficacy, while lateral translation and lateral tilt correlated with worse knee-related quality of life (Spearman's r ranging from 0.5 to 0.7). Conclusion Functional performance was worse in individuals with PFOA, despite those individuals having no significant differences on lower extremity strength testing. Patellofemoral alignment was associated with worse functional performance as well as worse patient-reported outcomes, and it may represent one mechanism underpinning PFOA-related symptoms

Lifetime physical activity and osteoarthritis

Introduction: The overall goal of this thesis is to improve understanding of physical activity (PA), one of the most important, modifiable but controversial risk factors in osteoarthritis (OA). OA is the major public health problem in musculoskeletal medicine and leading cause of physical disability in older adults. The ultimate purpose is to provide evidence to inform OA prevention strategies, something not currently available. Objectives: 1) To construct and describe lifetime trajectories of hip and knee joint force from physical activity in a large Canadian sample; 2) To validate self-report measures of medically-diagnosed OA and novel measures of joint vulnerability against clinical criteria; 3) To evaluate the relationship of lifetime joint force and hip and knee OA. Methods: PA data were collected online from 4,269 subjects via a validated PA survey in a national population-based cohort from 2005 to 2007 and subjects ranked and lifetime trajectories plotted in terms of the ‘cumulative peak force index’, a novel joint force measure. Validation studies were conducted in a sub-sample. Population-based multivariable studies examining the relationship between joint force and incident hip and prevalent knee OA were conducted. Results: 1) Overall women had slightly higher lifetime PA-related force then men. Six percent of subjects developed hip OA and seven percent knee OA during follow up. There was no risk from sport/recreational activity. Very high levels of total lifetime force (hip and knee), occupational force in men (knee) and household-related force in women (knee) were associated with an approximate 2-fold increase in risk of OA, as was previous joint injury (5-fold increase hip, 3-fold knee). At the knee, lower limb malalignment but not joint hypermobility, was associated with knee OA. Higher coordination was protective. Conclusions: Taken collectively, the results show that lifelong physical activity-related joint force is generally safe for the hip and knee, and the promotion of exercise as a major public health initiative should continue without concern for increased rates of OA. Very high levels of occupational force in men and household force in women were risk factors for knee OA. Joint injury, lower limb malalignment and lower coordination were associated with OA.Medicine, Faculty ofPopulation and Public Health (SPPH), School ofGraduat

Clinical findings in patellofemoral osteoarthritis compared to individually-matched controls: a pilot study

Objective To explore clinical characteristics in individuals with patellofemoral osteoarthritis (PFOA) compared to individually-matched asymptomatic controls. We also explored associations between functional performance and patient-reported symptoms with patellofemoral alignment.Methods We assessed 15 individuals with PFOA and 15 individually-matched asymptomatic controls. In addition to physical examination and patient-reported questionnaires, we evaluated functional performance, lower extremity strength and range of motion, and patellar alignment (using MRI). We analysed group differences with Wilcoxon’s matched-pairs signed rank tests, and within-group associations with Spearman’s rank correlations.Results We included 24 (80%) women with median (IQR) age of 56 (9) years and BMI of 22.8 (5.9) kg/m2. Individuals with PFOA reported lower quality of life (8/100 points lower EQ-5D-5L, p=0.02), and performed worse on two functional tests: repeated one-leg rises (median 16 fewer rises, p=0.04) and timed stair climb (1.2 s slower, p=0.03). There were no differences in strength tests performed or range of motion. Patellar proximal translation correlated with worse functional performance and worse patient-reported pain, function and self-efficacy, while lateral translation and lateral tilt correlated with worse knee-related quality of life (Spearman’s r ranging from 0.5 to 0.7).Conclusion Functional performance was worse in individuals with PFOA, despite those individuals having no significant differences on lower extremity strength testing. Patellofemoral alignment was associated with worse functional performance as well as worse patient-reported outcomes, and it may represent one mechanism underpinning PFOA-related symptoms

Patellofemoral and tibiofemoral alignment in a fully weight-bearing upright MR: implementation and repeatability

PurposeTo develop methods for evaluating 3D patellofemoral and tibiofemoral alignment in vertical open-bore magnetic resonance (MR) scanners, with participants upright and fully weight-bearing; and to evaluate the repeatability of these methods in individuals with patellofemoral osteoarthritis (OA) and in asymptomatic knees.Materials and MethodsOur methods extend previously validated, reliable methods for evaluating alignment into an upright MR environment. In 10 participants with early patellofemoral OA and 10 with asymptomatic knees, we acquired sagittal T-1-weighted turbo spin echo images in a 3T scanner to create accurate participant-specific 3D anatomical surface models. In a vertical open-bore 0.5T MR scanner, we obtained lower-resolution sagittal gradient echo images to capture bony position and orientation data. Participants were scanned in a position of squatting with the knees flexed 30 degrees, three separate times to evaluate repeatability. Bone segmentation was performed manually, surface models were registered to data from the 0.5T scanner, and 3D patellofemoral and tibiofemoral alignment was calculated in all six degrees of freedom (three rotations and three translations).ResultsIntraclass correlation coefficients (ICCs) were 0.94, with the exception of patellar spin (0.79). Standard errors of measure (SEM) wer

COS Ambassadors

A collection of materials and resources for COS ambassadors