Fig. 23
From: Fibrous dysplasia for radiologists: beyond ground glass bone matrix
The classification of femur deformities in fibrous dysplasia (FD). a Type 1. The neck-shaft angle is within normal limits (135°), but a distal femur shows 16° valgus deformity. b Type 2. The neck-shaft angle is valgus (152°). c Type 3. The neck-shaft angle is varus (100°). A distal shaft 10° demonstrates varus deformity. Distal juxta-articular valgus deformity is also present. d Type 4. The neck-shaft angle is normal (125°). Proximal lateral (shepherd’s crook) and distal medial bowing of the femoral shaft are present. e Type 5. The neck-shaft angle is valgus (160°). Lateral bowing of the proximal femur (shepherd’s crook) and medial bowing of the distal femur are present. f Type 6. FD affects the entire femur. Lateral bowing of the proximal femur is present at two levels (shepherd’s crook) as well as medial bowing of the distal femur. The neck-shaft angle is varus (100°) (reprinted from Ippolito et al. [21])