Focal fibrocartilaginous dysplasia of the distal femur.

Focal fibrocartilaginous dysplasia (FFCD) of the distal femur is a rare disorder that results in a varus or valgus of knee. Due to the small number of cases and unconfirmed natural history of the disease, treatment methods remain variable. This study aimed to determine a strategy to successfully manage distal femoral FFCD. Nine case of femoral FFCD treated in our department between 2008 and 2018, together with 22 cases from literature, were retrospectively reviewed. Tibiofemoral anatomical axis angle (TFA) was used to evaluate and follow the deformities. Treatment methods and outcome were analyzed. Five methods were used to manage the disease: osteotomy with tether release in 14 cases with mean TFA of 29°; simple tether release in eight cases with mean TFA of 31°; guide growth without tether release in 3 case with mean TFA of 27°; guide growth with tether release in 3 case with mean TFA of 27°; and observation in three cases with mean TFA of 23°.Deformity was resolved in all 31 patients. The analysis of the 31 cases in the literature and our experience suggests that femoral FFCD can be successfully managed by simple tether release and curettage. Osteotomy can be avoided. In case of mild deformity (TFA < 25°), it is reasonable to follow-up till 2-3 years of age; if no progress occurs, spontaneous resolution can be expected.