Varus–valgus alignment in the progression of patellofemoral osteoarthritis
Article first published online: 6 JUL 2004
Copyright © 2004 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 50, Issue 7, pages 2184–2190, July 2004
How to Cite
Cahue, S., Dunlop, D., Hayes, K., Song, J., Torres, L. and Sharma, L. (2004), Varus–valgus alignment in the progression of patellofemoral osteoarthritis. Arthritis & Rheumatism, 50: 2184–2190. doi: 10.1002/art.20348
- Issue published online: 6 JUL 2004
- Article first published online: 6 JUL 2004
- Manuscript Accepted: 16 MAR 2004
- Manuscript Received: 20 AUG 2003
- NIH (National Institute of Arthritis and Musculoskeletal and Skin Diseases). Grant Numbers: P60-AR-48098, R01-AR-48748
- NIH (National Center for Research Resources). Grant Number: RR-00048
To test the hypotheses that lateral patellofemoral (PF) osteoarthritis (OA) progression is more common than medial PF OA progression, that varus alignment increases the likelihood of medial PF OA progression, and that valgus alignment increases the likelihood of lateral PF OA progression.
Patients with knee OA were recruited from the community. Inclusion criteria were definite osteophyte presence (i.e., Kellgren/Lawrence radiographic grade ≥2) in 1 or both knees and at least some difficulty with knee-requiring activity. Varus–valgus alignment (the angle formed by the intersection of the mechanical axes of the femur and tibia) was measured on a full-limb radiograph at baseline. To assess PF OA progression, weight-bearing skyline views of the PF compartment were obtained at baseline and at 18-month followup. Knees with the highest grade of PF narrowing at baseline were excluded from analysis. Logistic regression and generalized estimating equations were used; odds ratios (ORs) were adjusted for age, sex, and body mass index.
Lateral PF OA progression, which occurred in 120 (30%) of 397 knees, was more common than was medial PF OA progression, which occurred in 60 knees (15%). Varus (versus nonvarus) alignment increased the odds of PF OA progression isolated to the medial PF compartment (adjusted OR 1.85, 95% confidence interval [95% CI] 1.00–3.44). Valgus alignment increased the odds of PF OA progression isolated to the lateral compartment (adjusted OR 1.64, 95% CI 1.01–2.66).
Lateral PF OA progression was more common than medial progression, and varus–valgus alignment influenced the likelihood of PF OA progression in a compartment-specific manner. Interventions that address the stress imposed by alignment on the PF compartments may delay PF OA progression and should be developed.