PT  - JOURNAL ARTICLE
AU  - SHREYASEE AMIN
AU  - JOYCE GOGGINS
AU  - JINGBO NIU
AU  - ALI GUERMAZI
AU  - MIKAYEL GRIGORYAN
AU  - DAVID J. HUNTER
AU  - HARRY K. GENANT
AU  - DAVID T. FELSON
TI  - Occupation-Related Squatting, Kneeling, and Heavy Lifting and the Knee Joint: A Magnetic Resonance Imaging-Based Study in Men
DP  - 2008 Aug 01
TA  - The Journal of Rheumatology
PG  - 1645--1649
VI  - 35
IP  - 8
4099  - http://www.jrheum.org/content/35/8/1645.short
4100  - http://www.jrheum.org/content/35/8/1645.full
SO  - J Rheumatol2008 Aug 01; 35
AB  - Objective We examined the relation between occupational exposures to frequent squatting/kneeling and/or heavy lifting with cartilage morphology, based on magnetic resonance imaging (MRI), at the tibiofemoral and patellofemoral joints in men and determined which compartments are most affected. Methods We evaluated 192 men with symptomatic knee osteoarthritis (OA). The more symptomatic knee was imaged using MRI. Cartilage was scored using the Whole Organ MRI Score semiquantitative method at the medial and lateral tibiofemoral joint and patellofemoral joint. Occupational exposures to frequent squatting, kneeling, and/or heavy lifting were assessed using a validated questionnaire. Results Among the 192 men [mean (± standard deviation) age 69 ± 9 yrs, body mass index (BMI) 30.8 ± 4.7 kg/m2], those reporting occupational exposure to squatting/kneeling alone, heavy lifting alone, both squatting/kneeling and heavy lifting, or none of these activities numbered 7, 40, 47, and 98, respectively. Compared with men with no occupational exposure to these activities, and following adjustment for age, BMI, and history of knee injury or surgery, we found that men reporting occupational exposures to both squatting/kneeling and heavy lifting had a modest increased risk for worse cartilage morphology scores at the patellofemoral joint [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.1 to 3.2] and medial tibiofemoral joint (OR 1.6, 95% CI 0.9, 3.0), although the latter did not reach statistical significance. Conclusion Men with frequent occupational squatting/kneeling and heavy lifting have a greater likelihood for worse cartilage morphology scores at the patellofemoral joint. These findings add support to the important role of biomechanical loading on the pathogenesis of knee OA, particularly patellofemoral OA.