EVALUATION OF THE RANGE OF MOTION OF A HIP ARTHROPLASTY SYSTEM: A COMPUTER SIMULATION STUDY.

Objective: To date, the literature lacks consensus on the most efficient method to measure the range of motion of an in vitro prosthetic system. In this study, we propose the use of a relatively low-cost online software to measure the range of motion of hip prosthetic implants manufactured in Brazil and compare its results with the current technical standards for hip arthroplasty.

Methods: Three different diameters of femoral heads were evaluated (28 mm, 32 mm, and 36 mm). The mean values of the angular displacement of the prosthesis in each motion axis were obtained by computer simulations.

Results: The range of motion with each femoral head was 28mm (extension/flexion: 148°, internal/external rotation: 179°, adduction/abduction: 107°), 32 mm (152°/185°/114°), and 36 mm (158°/193°/120°).

Conclusion: The computational method showed that the larger the femoral head, the greater the range of motion of the hip joint prosthetic system. Additional clinical studies are necessary to compare the physical results obtained with the values found in this study by computational modeling.