Frontal plane knee alignment is associated with a longitudinal reduction in patella cartilage volume in people with knee osteoarthritis

You will need to copy and paste the URL into a browser to view the abstract; a subscription is required to view the full text or it can be purchased online.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WP3-4RKDPPF-2&_user=10&_coverDate=07%2F31%2F2008&_rdoc=17&_fmt=high&_orig=browse&_srch=doc-info(%23toc%236979%232008%23999839992%23692857%23FLA%23display%23Volume)&_cdi=6979&_sort=d&_docanchor=&_ct=17&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=332b6e3f15e4e0714299e6a5eea01c91

Frontal plane knee alignment is associated with a longitudinal reduction in patella cartilage volume in people with knee osteoarthritis
Osteoarthritis and Cartilage
Volume 16, Issue 7, July 2008, Pages 851-854

A.J. Teichtahl M.B.B.S. (Hons.), B.Physio. (Hons.)‹, Dr., A.E. Wluka Ph.D., F.R.A.C.P., M.B.B.S.‹, ·, Dr. and F.M. Cicuttini Ph.D., F.R.A.C.P., M.B.B.S.‹, Professor flavia.cicuttini@med.monash.edu.au
‹Department of Epidemiology and Preventive Medicine, Monash University, Central and Eastern Clinical School, Alfred Hospital, Melbourne, Victoria 3004, Australia ·Baker Heart Research Institute, Commercial Road, Melbourne, Victoria 3004, Australia

Received 7 November 2007;
accepted 3 December 2007.
Available online 14 January 2008.

Summary
Objectives
VarusÒvalgus alignment of the knee is increasingly becoming recognised as an important biomechanical variable in patellofemoral osteoarthritis (OA). The aim of this study was to determine the cross-sectional and longitudinal relationships between frontal plane knee alignment and patella cartilage volume in people with knee OA.

Methods
Ninety-nine adults with symptomatic knee OA were recruited using a combined strategy including referral from specialist centres, arthritis support groups and media advertising. Both baseline and follow-up X-rays and magnetic resonance imaging (MRI) were performed 2 years apart. Knee alignment and patella cartilage volume were determined from X-ray and MRI, respectively.

Results
Annual change in knee alignment was negatively associated with an annual change in the total patella cartilage volume before (P = 0.002) and after (P = 0.003) adjustment for potential confounders over an average of a 1.9-year period. For every 1? change towards valgus direction, there was a 23.4-mm3 [95% confidence interval (CI) 8.1 mm3Ò38.7 mm3] annual reduction in the total patella cartilage volume.

Conclusion
This study is the first to clearly demonstrate and quantitate the annual reduction in patella cartilage volume that occurs as knee alignment becomes increasingly valgus in an osteoarthritic cohort. Interventions that aim to minimise change towards valgus alignment may reduce the risk for the onset and progression of patellofemoral OA.

Key words: Knee; Osteoarthritis; Alignment; Patella; Cartilage