Abstract TP327: Prevalence of Knee Pain and Associated Factors in Ambulatory Chronic Stroke Survivors

Introduction: Gait alterations after stroke have been linked to musculoskeletal complications, particularly around the knee joint. Knee pain may impede rehabilitation and reduce quality of life. However, its prevalence and associated factors are not well documented in the literature. Methods: We conducted a multicenter cross-sectional study in outpatient rehabilitation units at 12 hospitals in Vietnam. We enrolled chronic stroke survivors (6 months or more post-stroke) with a Functional Ambulation Category of 3 or greater. Demographic and stroke-related characteristics, comorbidities were recorded. Knee pain was assessed with Brief Pain Inventory pain subscale. Clinical measures included body mass index, Fugl-Meyer Assessment of Lower Extremity, Modified Tardieu Scale, weight-bearing asymmetry (two-scale method). Gait asymmetry indices and knee hyperextension classification were obtained from markerless analysis with 2D OpenPose. Health-related quality of life was measured with EQ-5D-5L. Bivariate analyses and multivariable logistic regression (backward stepwise method) were used to identify factors associated with knee pain. Results: A total of 212 ambulatory chronic stroke survivors were included. The prevalence of knee pain was 19.8%. Among those reporting knee pain, 50% experienced pain on the affected side, 31% on the unaffected side, and 19% bilaterally. Participants with knee pain had significantly lower quality of life scores than those without knee pain (p < 0.001). Independent factors associated with knee pain were prior history of knee osteoarthritis (OR = 9.94; 95% CI, 3.91–26.45; p < 0.001), hemorrhagic stroke (OR = 3.96; 95% CI, 1.74–9.12; p = 0.001), and time since stroke onset (OR = 1.01; 95% CI, 1.00–1.02; p = 0.037). Clinical examination measures and gait parameters were not associated with knee pain. In the subgroup with unilateral knee pain and no history of knee osteoarthritis, gastrocnemius contracture was greater in those with pain on the affected side than those with pain on the unaffected side (p = 0.026). Conclusions: Knee pain affected approximately one in five ambulatory chronic stroke survivors and was significantly associated with a history of knee osteoarthritis, hemorrhagic stroke, and longer time since stroke. Greater gastrocnemius contracture in those with pain on the affected side warrants further investigation.