Biomechanics Research Today is a free monthly online journal that collates and summarizes the latest research about Biomechanics, including details on mechanics of living organisms, movement, locomotion, prosthetic limbs.

Joint loading and bone mineral density in persons with unilateral, trans-tibial amputation.

Royer T, Koenig M

Department of Health, Nutrition, and Exercise Sciences, University of Delaware, 144 Rust Arena, Newark, DE 19716, USA. royer@udel.edu

BACKGROUND: Persons with unilateral, lower-extremity amputation sometimes develop osteoarthritis in the intact limb. The purpose of this study was to investigate gait mechanics and bone mineral density in unilateral, trans-tibial amputees to test the hypotheses that the intact limb knee and hip will have larger frontal plane net joint moments and bone mineral density than the prosthetic side and the limbs of control subjects. METHODS: Proximal tibia and femoral neck bone mineral density and gait mechanics were measured from nine subjects with a unilateral, trans-tibial amputation and from age, gender, and mass matched control subjects. FINDINGS: The amputee intact proximal tibia bone mineral density and peak knee internal abduction moment were 45% (P=0.001) and 56% (P=0.028) greater, respectively, than the prosthetic side. The intact limb femoral neck bone mineral density and peak hip internal abduction moment were 12% (P=0.095) and 33% (P=0.03) greater, respectively, than the prosthetic side. The intact knee frontal plane moment and bone mineral density were moderately larger than the control knee, while the intact and control hip were similar. INTERPRETATION: Elevated frontal plane net joint moments and bone mineral density suggest the potential exists for premature knee joint degradation. Measuring frontal plane joint mechanics and bone mineral density may be important tools for assessing joint health in persons with unilateral, trans-tibial amputation.

Published 8 November 2005 in Clin Biomech (Bristol, Avon), 20(10): 1119-25.
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