Objectives: The purpose of this report was to determine whether the muscle powers and the mechanical energies developed during the push-off period of the gait cycle of patients having a total hip prosthesis were different from able-bodied subjects as well as the effect on the nonoperated limb.
Design: Case control study.
Setting: All patients where independent and functional.
Patients: Four patients participated in the study. The indication for surgery was degenerative arthritis of the hip. There was also an able-bodied group.
Intervention: A Harris-Galante total hip prosthesis was used to restore hip stability and function. The patients were all operated on by the same orthopedic surgeon and had the same type of total hip replacement.
Main outcome measure: Gait analyses showed that not only the hips of the surgical group were affected but also the knees.
Results: Peak power did not show any significant difference except for a decrease in the frontal plane of the operated hip power absorption. The operated hip developed 35% and 48% less energy than that of the able-bodied group in the sagittal and frontal planes, respectively. The nonoperated hip was also affected and developed 35% more energy in the sagittal plane than the operated limb but 20% less than that of the able-bodied group. There was a reduction of 47% in the energies developed in the knees of the surgical patient group.
Conclusion: These results confirmed the presence of some mechanical dysfunction in the nonoperated limb.