fibrous dysplasia of long bones

Figuur 2:

Röntgenfoto’s van het proximale femur (heup) welke is aangedaan door fibreuze dysplasie. Op foto A is een normale weergave van proximale femur te zien. Op foto B is te een fibreuze laesie met typisch matglas aspect en afwezige weke delen reactie te zien. De vorm van het femur is op deze foto echter nog normaal. Op foto C is de herdersstaf afwijking te zien die typisch is voor een ernstige fibreuze dysplasie met herhaaldelijke (micro) fracturen waardoor het proximale femur in een bocht is gaan groeien. Die bocht wordt vaak vergeleken met de bocht in een herdersstaf.

Fibrous

dysplasia for radiologists: beyond ground glass bone matrix. The radiographic appearance of fibrous dysplasia (FD) and the rind sign. a–e Frontal radiographs demonstrate classic FD lesions in appendicular skeleton. A classic lucent lesion surrounded by a layer of sclerotic reactive bone (so-called the rind sign). The rind sign is most commonly seen in the proximal femur (red arrow)

Fibrous

dysplasia for radiologists: beyond ground glass bone matrix. “Evolution” of the fibrous dysplasia (FD) lesions. a Radiograph of a 3-year-old demonstrates a typical heterogeneous-appearing FD lesion in the femur. b Radiograph from an 11-year-old demonstrates homogeneous and radiolucent FD lesion. c Image from a 54-year-old patient shows sclerotic FD lesions

Fibrous

dysplasia for radiologists: beyond ground glass bone matrix. MRI in fibrous dysplasia (FD). a, b MRI typically shows sharply demarcated lesions with intermediate to low signal intensity on T1-weighted images (WI) and intermediate to high on T2-WI (red arrow). c Some FD lesions may also contain small cystic areas, which make the T2 signal bright (green arrow). d FD lesions usually show some degree of enhancement after contrast administration (blue arrow)

Fibrous

dysplasia for radiologists: beyond ground glass bone matrix. Benign myxoid bone matrix transformation in fibrous dysplasia (FD). a A patient with known FD of the femurs presents with an enlarging right thigh mass. b Axial unenhanced CT of the lower extremities shows a large heterogeneous mass in the right thigh replacing femur and causing mass effect on thigh muscles. Please note a normal position of the intramedullary road in the left femur. c The mass in the right thigh shows a focal 99m-Tc MDP radiotracer uptake. d Subsequently, the patient developed the same complication in the left leg. The image demonstrates extensive myxoid degeneration of the left femur

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])