The Kinematic Study for Stability of Contact Surface Area between Acetabular Cup and Femoral Prosthesis on the Flexion, Abduction, or External Rotation of the Hip Joint / 대한정형외과학회잡지

ABSTRACT

The range of acetabular cup and femoral prosthesis according to the different angle of insertion has been reported by many investigators. But no reports are still avairable about the surface area of the exposed femoral head at the position causing unstability of the femoral head. So the authors had studied the 3 types of prosthesis of Charnley, Muller and Mckee-Farrar and their acetabular cup by inserting them at different angles into the 10 human cadavaric skeleton to obtain the most stable position of the prosthesis and to calculate the surface area of the femoral head at the stable position. The result obtained are as follows. 1. In. Flexion Among 3 types of prosthesis, the maximum stability is 78% to the exposed area of the femoral head in Mckee-Farrar prosthesis with 10 of the femoral anteversion, 45 of acetabular inclination and 45 of acetabular anteversion. The minimum stability is 41% to the exposed area of the femoral head in Mckee-Farrar prothesis with femoral neutral version, 45 of acetabular inclination and 15 of acetabular retroversion. 2. In Abduction Among 3 types of prosthesis, the maximum stability is 86.5% to the exposed area of the femoral head in Mckee-Farrar prosthesis with 10 of the femoral anteversion, 45 of acetabular inclination and 45 of acetabular anteversion. The minimum stability is 50% to the exposed area of the femoral head in Muller prosthesis with femoral neutral version, 45 of acetabular inclination and 30 of acetabular retroversion. 3. In External Rotation Among 3 types of prosthesis, the maximum stability is 85. 8% to the exposed area of the femoral head in Mckee-Farrar prostbesis with femoral neutral version, 45 of acetabular inclination and 30 of acetabular retroversion. The minimum stability is 46% to the exposed area of the femoral head in Mckee-Farrar prosthesis with femoral neutral version, 30 of acetabular inclination and acetabular neutral version. 4. There was no relationship between the degree of range of the femoral prosthesis & acetabular cup and the amount of the surface area of the exposed femoral head when dislocated.