Surgical treatment of femoroacetabular impingement in a patient with Stickler syndrome: a case report.

Stickler syndrome is a multisystem connective tissue disorder caused by mutations in collagen genes that can present with craniofacial, ocular, audial, or skeletal abnormalities. Here, we report on a male patient with a COL2A1 missense mutation (c.647G>A; p.Gly216Asp). He complained of an out-toeing gait and restricted hip mobility. Radiographs showed broad and elongated femoral necks with coxa valga. An alpha angle of 119° and 96° for his left and right femur, respectively, and almost no femoral head-neck offset, suggested a femoroacetabular impingement. Considering the patient's unwillingness to receive a total hip replacement for his Tönnis grade 2 hips, we intended to establish impingement-free hips by causing minimizing trauma. Therefore, we performed an osteochondroplasty of femoral head-neck junction and gluteal muscle release without correcting coxa valgus through the surgical hip dislocation approach. The range of motion of his hips improved as the surgery restored the femoral head-neck offset. However, the patient experienced a sense of lower limb length disparity and hip instability, which might be caused by his uncorrected proximal femoral deformity. This case presents the previously unreported phenotypic features of a COL2A1 mutation G216D. Orthopedic surgeons should consider genetic disorders when confronting atypical abnormalities. Moreover, the primary deformity should be corrected in hip preservation surgeries. Insufficient deformity correction might contribute to unsatisfactory surgical outcomes.