Gait Analysis Of Metal On Metal Surface Arthroplasty
Michael A Mont, MD Baltimore MD (a, e - Wright Medical Technology)
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This study compared gait kinematics of resurfacing patients to normal hips, osteoarthritic hips, and patients with standard hip replacements. Metal-on-metal resurfacing is a type of hip arthroplasty in which there is conservation of the proximal femur. Little is known about the functional capabilities of patients with resurfacing. This study compared gait parameters of resurfacing patients with normal and osteoarthritic hip patients as well as those with standard hip replacements
Utilizing a gait analysis laboratory, the authors compared temporal-spatial parameters and hip kinematics during walking in patients with unilateral osteoarthritic hips, unilateral standard total hip replacements, and unilateral total hip resurfacing arthroplasty (Forty-one total patients; 15 standard total hip replacements, 15 resurfacing, and 11 unilateral hip osteoarthritis). Inclusion criteria for surgical patients included Harris Hip Scores > 90 points
and be minimum twelve months post-operative. All patients had gait analysis and the data compared to a matched for age and gender normal hip population. The gait parameters assessed included abduction moment, extensor moment, and walking speed.
Superior hip kinematics were found when resurfacing was compared to standard hip arthroplasty as well as osteoarthritic patients.
Resurfacing patients had kinematics (abduction moments, extension moments, walking velocity) that approached the normal patients without hip osteoarthritis. Deficits of patients with resurfacing were small.
Resurfacing patients had gait characteristics that were comparable to normal hips. Although standard hip replacements had markedly improved gait parameters when compared to osteoarthritic hips they never
approached resurfacing or normals. The reasons for these findings are unexplained but may be due to the large femoral head which deserves further investigation.