Pseudofracture

False appearance of midshaft fracture due to rotation or projection, especially in children.

A vascular channel in the bone may simulate a fracture.

Posttraumatic osteolysis

Fig. 5.10

Fig. 5.11a, b

Resorption of the distal or proximal ends of the clavicle. Acromioclavicular (AC) joint appears widened with erosions at the distal end.

May follow 6–8 wk after trauma at the AC joint.

Hyperparathyroidism

Generalized bone demineralization, erosion of the distal ends of the clavicles, and bone resorption along the inferior border of the distal clavicle at the attachment of the coracoclavicular ligament.

Brown tumor may be seen in primary hyper-parathyroidism (see Table 5.75 ). Pseudofractures (Looser zones).

Juvenile idiopathic arthritis (JIA)

Erosions at the ends of the clavicles with widening of AC joint.

Sternoclavicular joint involvement may be diff cult to appreciate on radiographs and may require cross-sectional imaging for detection of inflammatory changes.

Tumor

Fig. 5.12

Langerhans cell histiocytosis, aneurismal bone cyst, hemangioma. Clavicle is rare site of involvement for fibrous dysplasia, metastasis, osteosarcoma, Ewing sarcoma, leukemia, and lymphoma.

Neurofibromatosis

Pressure erosions. Tapering of the clavicle (“pencil pointing,” distal > proximal).

CRMO

Bone destruction, extensive sclerosis, and bone enlargement.

(see Table 5.1 )

Brachial plexus injury

Handlebar deformity is acquired presumably from neuromuscular weakness.

Radial ray defects (Holt-Oram syndrome, thrombocytopenia absent radius syndrome, Fanconi pancytopenia)

In addition to handlebar, clavicles may be hypoplastic with bulbous ends.

Campomelic dysplasia

Fig. 5.14a, b

Hypoplastic tibia, scapula, and vertebral bodies. Pear-shaped iliac bones, long femora that are anteriorly bowed, and deficient ossification of the pubis.

Lethal skeletal dysplasia. Pulmonary hypoplasia and laryngeal and tracheal stenosis. Ureteral stenosis. Thoracic platyspondyly and kyphosis. Multiple cutaneous dimples in the arms and legs.

Cornelia de Lange syndrome

(see Table 5.50 )

Posttraumatic pseudarthrosis

Continued lucency through the fracture with smooth fracture margins and adjacent sclerosis beyond when healing with union is expected. Exuberant callus formation without bridging.

Nonunion common in fractures that occur distal to the coracoclavicular ligament attachment.

Cleidocranial dysplasia

Fig. 5.15a–d

Hypoplastic or absent clavicles: often central portion of the clavicle is absent with rudimentary medial and lateral portions remaining.

Clavicle findings may be confused with congenital pseudarthrosis.

Postsurgical resection

Fig. 5.16

Trisomy 13 and 18

Cleidocranial dysplasia

Fig. 5.15a–d

(see Table 5.13 )

Otopalatodigital spectrum (e.g., Melnick-Needles syndrome)

(see Table 5.26 )

Scoliosis, joint subluxations, long fingers and toes.

Pycnodysostosis

Generalized bone sclerosis and mild modeling deformity of the bones.

Short-limbed dwarfism with generalized increase in bone density. Acroosteolysis. Brittle bones.

Thalassemia

Generalized osteopenia and coarse trabecular pattern in the intramedullary cavity.

Myeloid hyperplasia produces the radiographic findings that commonly involve the clavicle.

Poland syndrome

Absence of the pectoralis major muscle and syndactyly.

Other associated chest wall abnormalities: deformity of the sternum, absence or atrophy of the second to fifth ipsilateral ribs and other chest wall muscles, aplasia of the ipsilateral breast or nipple, and simian crease of the affected extremity.

Primary hyperoxaluria (oxalosis)

Sclerosis and bulbous deformity of the me-dial ends (drumstick clavicles). Osteoporosis in the early phase and diffuse bone sclerosis in the advanced stage. Subchondral sclerosis in the long bones. Metaphyseal sclerosis, dense epiphyses.

Growing ends of bones show bulbous enlargement. Pathologic fractures are common. Growth disturbance and increased incidence of urinary calculi due to hyperoxaluria.