Patients with Symptomatic Hip Osteoarthritis Have Altered Kinematics during Stair Ambulation

Background Osteoarthritis (OA) is a degenerative joint disease. Understanding contributing factors to slowing or stopping disease progression is crucial. There has been no research describing lower extremity kinematics of the hip, knee, and ankle during stair ambulation in individuals with hip OA. Objective To explore the differences in lower extremity kinematics between participants with clinical and morphological findings of hip OA and controls. Design A cross-sectional study. Setting Clinical research laboratory. Participants Participants with radiographic and symptomatic signs of hip OA (n = 42) and healthy controls (n = 30) were enrolled. Interventions Participants underwent hip magnetic resonance imaging (MRI). The Scoring Hip Osteoarthritis with MRI (SHOMRI) method was used to assess cartilage abnormalities. Self-reported measures of hip pain and function were obtained using the Hip Disability and Osteoarthritis Outcome Score (HOOS). Participants were assigned into a symptomatic hip osteoarthritis group (HOA) with SHOMRI>0 and HOOS <= 80, and a control group (CG) with SHOMRI = 0 and HOOS>90. Patients underwent 3D motion analysis during stair ascent/descent at self-selected speed. Main Outcome Measures The primary outcome measurements were peak hip, knee, and ankle kinematics. General Estimation Equations were used to compare kinematics between groups (P <= .05). Results The HOA group ascended stairs with a more internally rotated hip (CG = 1.77 +/- 6.3; HOA = 4.97 +/- 4.2; P = .02), more abducted hip (CG = -5 +/- 2.7, HOA = -3.5 +/- 3; P = .02), and a more externally rotated knee (CG = -8.02 +/- 3; HOA = -10.63 +/- 6.3; P = .02) and ankle (CG = -11.8 +/- 6.1; HOA = -16.3 +/- 5.6; P = .01). Similarly, HOA participants descended stairs with a more extended knee (CG = -15.5 +/- 4.9; HOA = -12 +/- 4.9; P = .01), and more externally rotated knee (CG = -10.1 +/- 4.4; HOA = -13.1 +/- 6.6; P = .04) and ankle (CG = -13.5 +/- 5.3; HOA = -17.9 +/- 5.5; P = .002). Conclusion Participants with hip OA-related morphology and symptoms ambulate stairs utilizing abnormal lower extremity mechanics.