Differences in gait kinematics and kinetics between patients 1 year after total hip or knee arthroplasty and healthy controls

BACKGROUND: Patients undergoing unilateral total hip arthroplasty (THA) or total knee arthroplasty (TKA) often develop osteoarthritis (OA) of the contralateral knee or hip joint. The aim of the study was to compare gait kinematics and kinetics in joints of the contralateral and ipsilateral side of patients after THA or TKA to controls. METHODS: 103 participants (45 THA; 30 TKA; 28 controls) completed three-dimensional instrumented gait analysis. Differences in lower extremity kinematic and kinetic trajectories between each patient group and controls were analyzed using statistical parametric mapping with t-tests (p < 0.05). FINDINGS: Compared to controls, patients after TKA had greater hip flexion and ankle dorsiflexion angles during terminal stance and pre-swing and greater knee adduction during terminal stance and lower ankle dorsiflexion moments on the contralateral side. On the ipsilateral side, patients with TKA had greater sagittal ankle angles during loading response, greater hip angles in terminal stance and lower ankle moments than controls. THA patients had smaller hip adduction angles during loading response and larger knee flexion angles during early stance on the ipsilateral side. Patients after TKA walked slower than controls, whereas patients after THA walked at similar speeds. INTERPRETATION: Differences in kinematic and kinetic patterns compared to controls were not only evident in the operated joint but also in the adjacent and contralateral joints in patients after TKA, but only in the ipsilateral joints in patients after THA. This suggests that 1 year after surgery, patients after THA recover faster in the contralateral joints than patients after TKA.