Mustafa Onur Karaca, Mustafa Özyıldıran, Mahmut Kalem, Yunus Şamil Gönüldenk, Kerem Başarır, Hüseyin Hakan Kınık, Hüseyin Yusuf Yıldız
Joint Diseases and Related Surgery - 2026;37(2):531-542
Fibrous dysplasia (FD) is a benign bone lesion characterized by the replacement of normal bone with fibro-osseous tissue due to a developmental disorder of bone. This study aimed to evaluate the rate of proximal femoral involvement and the incidence of shepherd's crook deformity in patients with FD, and to identify possible factors associated with its development. A total of 158 patients diagnosed with FD were retrospectively analyzed. Shepherd's crook deformity was observed in nine of 75 proximal femoral lesions (12.0%). The deformity was significantly more common in polyostotic than in monostotic lesions (25.0% vs. 5.9%, p = 0.026) and in patients with McCune-Albright syndrome (MAS) (100% vs. 9.6%, p = 0.013). Valgus osteotomy was performed in all nine patients with shepherd's crook deformity, improving the mean neck-shaft angle. However, recurrence of deformity and the need for secondary surgery were observed in three patients. Most lesions can be managed with observation, while surgery is indicated for symptomatic lesions, prevention of pathological fractures, and correction of deformities. Shepherd's crook deformity seems to be more common in patients with polyostotic lesions and MAS.
