Increased varus/valgus laxity and perceived knee instability are independently associated with poor outcomes in people with knee osteoarthritis. However, the relationship between laxity and perceived instability is unclear.
To assess whether knee extensor strength, pain, and knee laxity are related to perceived knee instability in patients with advanced knee osteoarthritis.
This was a secondary analysis of a prospective observational cohort study of 35 patients (24 female; mean ± SD age, 60 ± 8 years; body mass index, 33 ± 5 kg/m
Lower knee extension strength (
Level 2, prognostic. 
Knee extension strength and pain were associated with perceived instability in people with advanced osteoarthritis. Varus/valgus laxity was not related to perceived knee instability.