Protrusio acetabuli in Marfan syndrome. History, diagnosis, and treatment.

Marfan syndrome is an autosomal dominant disorder of connective tissue, with ocular, skeletal, and cardiovascular manifestations. Protrusio acetabuli is a criterion for the diagnosis of Marfan syndrome. Prolonged protrusio acetabuli may result in secondary osteoarthritic changes in the hip joint. Radiographic criteria for protrusio acetabuli include an abnormally positioned acetabular line, a center-edge angle of Wiberg of >40 degrees, and crossing of the teardrop by the ilioischial line. In a skeletally immature patient with Marfan syndrome in whom the triradiate physis of the acetabulum is still open, closure of the triradiate physis can interrupt and decrease the progression of the deformity. In older patients, valgus intertrochanteric osteotomy and eventually total hip arthroplasty are the only methods available for correction of the protrusio acetabuli.