Commonest location of aneurysmal bone cyst is: September 2006

Ans. D: Tibia Regarding the location of the aneurysmal bone cyst, any bone may be affected. Approximate frequencies by site are: Skull and mandible (4%) Spine (16%) Clavicle and ribs (5%) Upper extremity (21%) Pelvis and sacrum (12%) Femur (13%) Lower leg (24%) Foot (3%) Sho tubular bones are less frequently affected and are involved in about 10% of cases. Spinal involvement demonstrates a predilection for the posterior elements. In decreasing order of frequency, the following pas of the spine are involved: cervical, thoracic, lumbar. Contiguous veebrae may be involved in 25% of cases. The cyst involves the diaphysis in isolation in about 8% of cases