Lateral cartilage defects and medial subchondral surface ratio are associated with knee‐related disability

ABSTRACT We sought to determine the relationship between (i) full‐thickness cartilage defects and tibiofemoral subchondral surface ratio (SSR) and (ii) disability and quality of life in patients with mild radiographic osteoarthritis (OA) (Kellgren‐Lawrence grade 2) or without radiographic OA (Kellgren‐Lawrence grades 0 or 1)? A total of 642 participants from the Osteoarthritis Initiative (OAI) with baseline knee MRIs and a Kellgren‐Lawrence grade 2 or less on both bilateral screening radiographs were included. The independent relationship was assessed between (i) full‐thickness cartilage defect presence and tibiofemoral SSR and (ii) Knee Injury and Osteoarthritis Outcome Score (KOOS) quality of life (QOL), KOOS function in sports and recreation (KOOS‐sport/rec), and Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability score after adjustment for relevant confounders with multivariate regression modeling. The prevalence of medial full‐thickness defects was 10.4% (67/642) and lateral was 18.1% (116/642). Lateral defect presence was associated with worse KOOS‐QOL (beta −3.61 SE 1.04; p = 0.001), KOOS‐sport/rec (beta −4.70 SE 1.38; p = 0.001) and WOMAC‐disability scores (beta 0.02 SE 0.01; p = 0.001); these associations were not influenced by defect size. A larger medial compartment SSR was associated with worse KOOS‐QOL (beta −27.20 SE 6.80; p