Proximal femoral focal deficiency, PFFD, is a congenital anomaly of the pelvis and proximal femur which causes hip deformity and shortening and altered function of the involved lower extremity. The condition may be unilateral or bilateral and is often associated with other congenital anomalies.

Dwarfism, Madelung Deformity. NORD Database
Dyschondrosteosis is a very rare inherited disorder characterized by unusually shortened, bowed bones in the forearms (radius and ulna), abnormal deviation of the wrist toward the thumb side of the hand due to shortening of the radius and dislocation of the end portion of the ulna (Madelung deformity), unusually short lower legs, and associated short stature (mesomelic dwarfism). Affected individuals may also exhibit abnormalities of the large bone of the upper arm (humerus); abnormal bony growths projecting outward from the surface of the shin bones (exostoses of the tibia); unusually short, broad bones in the fingers and toes; and/or abnormalities of the hipbone (i.e., coxa valga). Dyschondrosteosis appears to affect females more severely than males. The disorder is inherited as an autosomal dominant or "pseudoautosomal" trait.

Wheeless' Textbook of Orthopaedics
- a development defect of the proximal femur recongnizable at birth;
- 3rd most common longitudinal deficiency of lower extremity;
- abnormality ranges from hypoplasia of entire femur to complete absence of the proximal end;
- bilateral involvement is seen in 15% of patients;