Knee flexion contractures in patients with osteoarthritis: clinical features and histologic characterization of the posterior capsule.

Objective: To (1) identify demographic and clinical factors associated with knee flexion contracture (KFlC) in the setting of osteoarthritis (OA) and (2) histologically compare the posterior knee capsule of patients with OA with and without KFlC.

Design: Cross-sectional study.

Setting: Primary care, including private and institutional practice.

Genome wide gene expression analysis of the posterior capsule in patients with osteoarthritis and knee flexion contracture.

Objective: Knee flexion contractures (KFC) are limitations in the ability to fully extend the knee joint. In people with knee osteoarthritis (OA), KFC are common, impair function, and worsen outcomes after arthroplasty. In KFC, the posterior knee capsule is believed to play a key role, but the pathophysiology remains poorly understood.