Elsevier

Osteoarthritis and Cartilage

Volume 22, Issue 12, December 2014, Pages 2067-2073
Osteoarthritis and Cartilage

Proximal femur shape differs between subjects with lateral and medial knee osteoarthritis and controls: the Osteoarthritis Initiative

https://doi.org/10.1016/j.joca.2014.08.013Get rights and content
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Summary

Objective

This study examined the association of proximal femur shape with ipsilateral medial and lateral compartment knee osteoarthritis (OA).

Design

Radiographs were obtained from the NIH-funded Osteoarthritis Initiative (OAI). Cases of isolated radiographic lateral compartment knee OA were defined on baseline radiographs as Kellgren/Lawrence (K/L) Grade ≥ 2 and joint space narrowing (JSN) > 0 in the lateral compartment and JSN = 0 in the medial compartment; isolated medial compartment knee OA had K/L ≥ 2 and JSN > 0 medially with JSN = 0 in the lateral compartment. Controls had K/L < 2 and JSN = 0 in both compartments. Controls were frequency matched to cases by sex and 10-year age intervals. We characterized the shape of the proximal femurs on radiographs using Active Shape Modeling (ASM) and determined the association of proximal femur shape with knee OA using logistic regression.

Results

There were 168 lateral compartment knee OA cases (mean body mass index (BMI) 29.72 ± 5.26), 169 medial compartment knee OA cases (mean BMI 29.68 ± 4.83) and 168 controls (mean BMI 26.87 ± 4.2). Thirteen modes were derived for femur shape which described 95.5% of the total variance in proximal femur shape in the population. Modes 6, 8 and 12 were associated with prevalent lateral compartment knee OA. Medial compartment knee OA was associated with proximal femur modes 1, 5, 8, and 12.

Conclusions

Prevalent lateral and medial compartment knee OA are associated with different ipsilateral proximal femur shapes. Additional studies are needed to better define how the shape of the proximal femur influences compartment-specific knee OA.

Keywords

Hip
Knee
Osteoarthritis
Shape
Compartment

Cited by (0)

This work was supported by the following funding sources: the Center for Musculoskeletal Health at University of California, Davis School of Medicine; NIH K24 AR048841 (NEL); NIH P50 AR060752 (BLW, NEL); NIH P50 AR063043 (BLW, NEL); the University of California, Davis Building Interdisciplinary Research Careers in Women's Health Program (NIH K12HD051958) (BLW); and the Endowed Chair for Aging at University of California, Davis School of Medicine (NEL). The Osteoarthritis Initiative (OAI) is a public–private partnership comprised of 5 contracts (N01-AR-2-2258, N01-AR-2-2259, N01-AR-2-2260, N01-AR-2-2261, and N01-AR-2-2262) funded by the NIH, a branch of the Department of Health and Human Services, and conducted by the OAI Study Investigators. Private funding partners include Pfizer, Novartis Pharmaceuticals, Merck Research Laboratories, and GlaxoSmithKline. Private sector funding for the OAI is managed by the Foundation for the NIH.