Wandering acetabulum is seen in: (E. REPEAT 2012)

Ref: Tuberculosis of the Skeletal System by SM Tali, Pages 70--81 and Mercer's Orthopaedic Surgery, 0th edition, Duthie, Bentley and Dhal. Page 604Explanation:RADIOLOGICAL FINDINGS IN TB HIPThe earliest radiological sign on X-Rays is a slight loss of hone density (osteopenia) due to synovial edema.Excessive synovial thickening.Soft tissue shadows.Stages of Tuberculosis of HipFirst stage:o Synovial effusiono Increased joint space.Second stage:o Cartilage destructiono Slight diminution of joint spaceo Localized erosions at margins.Third stage:o Gross destruction of the articular cartilage.o Bony destruction of the femoral head and acetabulum (Kissing lesions).Fourth stage IV:o Advanced arthritiso Pathological dislocationo Wandering acetabulumo Protrusio acetabulio Mortar and pestle.CHARACTERISTIC FINDINGS IN TUBERCULOSIS OF JOINTSWandering acetabulumo Roof of acetabulum which articulates maximum with the femoral head erodeso Femoral head displaces upwards anddorsallv leaving the lower part of acetabulum empty.Mortar and pestle appearanceo Femoral head and neck are grossly destroyed, they collapse and are contained in an enlarged acetabulum giving a mortar and pestle appearance.Triple deformity of kneeo Seen in tuberculosis of the kneeo Consists of flexion deformity, external rotation deformity and posterior subluxation of tibia.