Normal hip joint contact pressure distribution in single-leg standing - effect of gender and anatomic parameters

A practical and easy-to-use analysis technique that can study the patient's hip joint contact force/pressure distribution would be useful to assess th e effect of abnormal biomechanical conditions and anatomical deformities on joint contact stress for treatment planning purpose. This technique can al so help to establish the normative database on hip joint contact pressure d istribution in men and women in different age groups. Twelve anatomic param eters and seven biomechanical parameters of the hip joint in a normal popul ation (41 females, 15 males) were calculated. The inter-parameter correlati ons were investigated. The pressure distribution in the hip joint was calcu lated using a three-dimensional discrete element analysis (DEA) technique. The 3D contact geometry of the hip joint was estimated from a 2D radiograph by assuming that the Femoral head and the acetabular surface were spherica l in shape. The head-trochanter ratio (HT), femoral head radius, pelvic hei ght, the joint contact areal the normalized peak contact pressure, abductor force, and the joint contact force were significantly different between me n and women. The normalized peak contact pressure was correlated both with acetabular coverage and head-trochanter ratio. Change of abductor force dir ection within normal variation did not affect the joint peak contact pressu re. However, in simulated dysplastic conditions when the CE angle is small or negative, abductor muscle direction becomes very sensitive in joint cont act pressure estimation. The models and the results presented can be used a s the reference base in computer simulation for preoperative planning in pe lvic or femoral osteotomy. (C) 2001 Elsevier Science Ltd. All rights reserv ed.