Dr. Cooke owns stock or stock options in OAISYS, Inc. and holds patents for image analysis technology.
Valgus malalignment is a risk factor for lateral knee osteoarthritis incidence and progression: Findings from the multicenter osteoarthritis study and the osteoarthritis initiative
Version of Record online: 28 JAN 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 65, Issue 2, pages 355–362, February 2013
How to Cite
Felson, D. T., Niu, J., Gross, K. D., Englund, M., Sharma, L., Cooke, T. D. V., Guermazi, A., Roemer, F. W., Segal, N., Goggins, J. M., Lewis, C. E., Eaton, C. and Nevitt, M. C. (2013), Valgus malalignment is a risk factor for lateral knee osteoarthritis incidence and progression: Findings from the multicenter osteoarthritis study and the osteoarthritis initiative. Arthritis & Rheumatism, 65: 355–362. doi: 10.1002/art.37726
- Issue online: 28 JAN 2013
- Version of Record online: 28 JAN 2013
- Accepted manuscript online: 30 NOV 2012 04:07PM EST
- Manuscript Accepted: 25 SEP 2012
- Manuscript Received: 14 JUN 2012
- NIH. Grant Numbers: U01-AG-18820, U01-AG-18832, U01-AG-18947, U01-AG-19069, P60-AR-47785, R01-AR-051568, R01-HD-43500
- The Osteoarthritis Initiative (OAI) is a public-private partnership comprising five NIH contracts. Grant Numbers: N01-AR-2-2258, N01-AR-2-2259, N01-AR-2-2260, N01-AR-2-2261, N01-AR-2-2262
- OAI Study Investigators
- Merck Research Laboratories
- Novartis Pharmaceuticals Corporation
- Pfizer, Inc.
- Foundation for the National Institutes of Health
To study the effect of valgus malalignment on knee osteoarthritis (OA) incidence and progression.
We measured the mechanical axis from long limb radiographs from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) to define limbs with valgus malalignment (mechanical axis of ≥1.1° valgus) and examined the effect of valgus alignment versus neutral alignment (neither varus nor valgus) on OA structural outcomes. Posteroanterior radiographs and knee magnetic resonance (MR) images were obtained at the time of the long limb radiograph and at followup examinations. Lateral progression was defined as an increase in joint space narrowing (on a semiquantitative scale) in knees with OA, and incidence was defined as new lateral narrowing in knees without radiographic OA. We defined lateral cartilage damage and progressive meniscal damage as increases in cartilage or meniscus scores at followup on the Whole-Organ Magnetic Resonance Imaging Score scale (for the MOST) or the Boston Leeds Osteoarthritis Knee Score scale (for the OAI). We used logistic regression with adjustment for age, sex, body mass index, and Kellgren/Lawrence grade, as well as generalized estimating equations, to evaluate the effect of valgus alignment versus neutral alignment on disease outcomes. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs).
We studied 5,053 knees (881 valgus) of subjects in the MOST cohort and 5,953 knees (1,358 valgus) of subjects in the OAI cohort. In both studies, all strata of valgus malalignment, including 1.1° to 3° valgus, were associated with an increased risk of lateral disease progression. In knees without radiographic OA, valgus alignment >3° was associated with incidence (e.g., in the MOST, adjusted OR 2.5 [95% CI 1.0–5.9]). Valgus alignment >3° was also associated with cartilage damage on MR imaging in knees without OA (e.g., in the OAI, adjusted OR 5.9 [95% CI 1.1–30.3]).We found a strong relationship of valgus malalignment with progressive lateral meniscal damage.
Valgus malalignment increases the risk of knee OA radiographic progression and incidence as well as the risk of lateral cartilage damage. It may cause these effects, in part, by increasing the risk of meniscal damage.