Maturitas 66 (2010) 72–76 Contents lists available at ScienceDirect Maturitas journal homepage: www.elsevier.com/locate/maturitas Occupational activity is associated with knee cartilage morphology in females Andrew J. Teichtahl a , Anita E. Wluka a , Yuanyuan Wang a , Donna M. Urquhart a , Fahad S. Hanna a , Patricia A. Berry a , Graeme Jones b , Flavia M. Cicuttini a,∗ a Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Central and Eastern Clinical School, Alfred Hospital, Melbourne, Vic 3004, Australia b Menzies Research Institute, University of Tasmania, Hobart, Australia article info Article history: Received 20 November 2009 Received in revised form 20 January 2010 Accepted 22 January 2010 Keywords: Knee Female Occupation Osteoarthritis Cartilage abstract Introduction: Knee osteoarthritis (OA) is a major cause of pain and disability in women, becoming a major health problem in mid to later life. A better understanding of factors contributing to deleterious structural knee changes may be important for preventing OA. In men, occupations associated with frequent knee bending have been shown to be associated with damage to knee cartilage. This has not been examined in women. The aim of this study was to examine the effect of occupational specific knee activities on tibial and patella cartilage morphology among healthy females. Methods: 96 females aged 26–62 years with no history of knee injury or symptoms were recruited as part of a study of community-based study of lifestyle factors on knee health. Occupational activity data examining the frequency of tasks such as heavy lifting, knee bending, stair climbing, walking and standing were obtained by questionnaire. Tibial and patella cartilage volumes and defects were measured from magnetic resonance imaging using validated methods. Results: Heavy lifting/bending/squatting, knee bending, stair climbing and walking were all associated with an increased risk of patella, but not tibial, cartilage defects (odds ratio 1.8–2.9; p ≤ 0.05) after adjust- ment for potential confounders, including knee alignment and radiographic joint space narrowing. There was a trend towards knee bending being associated with a reduction in patella cartilage volume (p = 0.07). Conclusion: Our results demonstrate that asymptomatic adult females with occupations requiring fre- quent knee bending have patella, but not tibial cartilage damage. These findings suggest that vocational tasks requiring knee bending are detrimental to the structure of cartilage in females and may be an area to consider in the prevention of knee OA. Crown Copyright © 2010 Published by Elsevier Ireland Ltd. All rights reserved. 1. Introduction Knee osteoarthritis (OA) is the most common arthropathy and is more prevalent in females than in males, with the peak incidence for disease occurring in mid to late life. Lifestyle factors may be important in the development of OA, and offer a potential target for the prevention of knee OA. Nevertheless, there is limited data exploring the role that occupation, and in particular, occupational specific activities may have in the pathogenesis of OA. Among the small number of studies, there is evidence that cer- tain occupations are associated with an increased risk of knee osteoarthritis (OA). For instance, it has been demonstrated that occupations requiring heavy labour are associated with the highest risk of knee OA for both men and women [1]. Similarly, a retro- spective cohort study of 778 subjects demonstrated that men and ∗ Corresponding author. Tel.: +61 3 9903 0555; fax: +61 3 9903 0556. E-mail address: flavia.cicuttini@med.monash.edu.au (F.M. Cicuttini). women who had worked in the building and construction industry had an increased risk of prevalent knee OA [2]. Likewise, there is a significantly increased risk of surgically treated knee OA among heavy labourers [3]. Nevertheless, there are a paucity of studies examining which aspect of vocational activities may mediate joint damage. Several studies have demonstrated that knee OA is common among those in occupations that require knee flexion [4–6], such as floor layers and carpenters [7]. Similarly, a systematic review also concluded that the kneeling working position and lifting at work were associated with knee pain [8]. It may therefore be that occupations requiring knee flexion in excess of normal activities of daily living may be detrimental to the knee joint. Biomechan- ically, tasks requiring significant degrees of knee flexion increase retropatellar load and may therefore be expected to predispose to patellofemoral, rather than tibiofemoral compartment pathology. Despite this, the predominance of previous studies have examined the effect of occupation on only the tibiofemoral compartment of the knee, while the patellofemoral compartment has not been examined. 0378-5122/$ – see front matter. Crown Copyright © 2010 Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2010.01.014