OSTEOID OSTEOMA July 2012 Osteoid osteoma

OSTEOID OSTEOMA Small, benign bone lesion with a nidus of less than 2 cm surrounded by a zone of reactive bone. July 2012 Osteoid osteoma

AETIOLOGY UNKNOWN July 2012 Osteoid osteoma

INCIDENCE 1O% OF BENIGN BONE TUMOURS Male:Female 2:1 5-25 years Rare over 40 years July 2012 Osteoid osteoma

LOCATION Proximal femur , Tibia Spine = posterior elements diaphysis or metaphysis July 2012 Osteoid osteoma

CLINICAL DULL PAIN Worse at night Relieved by aspirin 10% spine  scoliosis Other : Joint effusion, LLD, synovitis Pain decreases by 18-30 months July 2012 Osteoid osteoma

RADIOLOGY Radiolucent nidus Surrounded by sclerotic bone Center of nidus may be calcified Hot spot on Tc - scan July 2012 Osteoid osteoma

July 2012 Osteoid osteoma

DIFFERENTIAL DIAGNOSIS Osteoblastoma Brodie’s abscess Fatigue fracture July 2012 Osteoid osteoma

PATHOLOGY Nidus usually < 1 cm Nidus = thick vasculas bars of osteoblastic tissue, surrounded by vascular fibrous tissue and mature reactive cortical bone July 2012 Osteoid osteoma

TREATMENT NSAIDS SURGICAL – excision Percutaneous radiofrequency ablation July 2012 Osteoid osteoma