Knee laxity after staircase exercise predicts radiographic disease progression in medial compartment knee osteoarthritis
Version of Record online: 28 NOV 2012
Copyright © 2012 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 64, Issue 12, pages 3908–3916, December 2012
How to Cite
Miyazaki, T., Uchida, K., Sato, M., Watanabe, S., Yoshida, A., Wada, M., Shimada, S., Kuiper, J. H. and Baba, H. (2012), Knee laxity after staircase exercise predicts radiographic disease progression in medial compartment knee osteoarthritis. Arthritis & Rheumatism, 64: 3908–3916. doi: 10.1002/art.34662
- Issue online: 28 NOV 2012
- Version of Record online: 28 NOV 2012
- Accepted manuscript online: 8 AUG 2012 11:59AM EST
- Manuscript Accepted: 31 JUL 2012
- Manuscript Received: 22 JAN 2012
To evaluate whether increased laxity of the knee during daily physical activities such as stair climbing is associated with progression of knee joint osteoarthritis (OA).
During the years 2001–2003, 136 patients with bilateral primary medial compartment knee joint OA were enrolled in this prospective study. Baseline data collected were body mass index (BMI), muscle power, radiographic joint space width, mechanical axis on standing radiography, and anteroposterior (AP) knee laxity before and after physical exercise. After 8 years of followup, 84 patients were reexamined to assess radiographic changes. Radiographic disease progression was defined as progression of >1 grade on the Kellgren/Lawrence scale.
AP knee laxity increased significantly after stair climbing. Patients with OA progression and those without progression did not differ significantly in age, sex, baseline quadriceps muscle strength, mechanical axis, joint space width, and AP knee laxity before exercise. The 2 groups of patients did, however, differ significantly in baseline BMI and change in AP knee laxity due to exercise. The risk of progression of knee OA increased 4.15-fold with each millimeter of increase in the change in AP knee laxity due to exercise and 1.24-fold with each point increase in the BMI.
Our results indicate that patients with OA progression have significantly greater changes in knee joint laxity during physical activities and a higher BMI than patients without OA progression. These findings suggest that larger changes in knee laxity during repetitive physical activities and a higher BMI play significant roles in the progression of knee OA.