A technique for determining femoral head containment during gait.

Kinematic gait analysis was carried out on 42 hips, including normal joints and joints affected with Legg-Calvé-Perthes disease. Data were analyzed by a computer algorithm that calculated three-dimensional femoral head contact with the acetabulum (containment). Patients were studied in and out of various abduction orthoses. The three-dimensional containment of the hip is reproducibly altered by various devices; specifically, the Atlanta brace increases posterior coverage and slightly increases lateral coverage, and Petrie casts improve lateral and anterior coverage at the expense of posterior containment. This analysis allows modeling of osteotomies and enhances clinical assessment of actual changes in containment with bracing.