title: Pseudoacetabulum a subtle radiological feature of a chronic dislocated total hip replacement.
abstract: We report the presence of an unusual radiological feature of formation of pseudoacetabulum in a chronically dislocated and asymptomatic total hip arthroplasty. An elderly demented patient with a history of recurrent dislocations presented to us after an unwitnessed fall and leg length discrepancy. Radiographs showed a dislocated hip arthroplasty with a well-defined, concentric, radio-opaque shadow around the dislocated femoral head suggestive of a pseudoacetabulum. Previous radiographs revealed formation of heterotopic ossification in the soft tissues surrounding the hip. The dislocated joint was reduced under a general anaesthetic with difficulty. This case highlights the presence of heterotopic ossification and formation of pseudoacetabulum as subtle radiological features of chronic instability and dislocation.
authors.affiliation: Royal Liverpool University Hospital, Warrington, UK. saurabhsodak@gmail.com
authors.forename: Saurabh
authors.initials: S
authors.lastname: Odak
authors.forename: Jitendra
authors.initials: J
authors.lastname: Mangwani
authors.forename: John
authors.initials: J
authors.lastname: Ivory
mesh_terms: D000058:Accidental Falls; D000077:Acetabulum; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D002908:Chronic Disease; D003704:Dementia / Q000150:complications; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D006617:Hip Dislocation / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D006621:Hip Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D007870:Leg Length Inequality / Q000150:complications; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging* / Q000601:surgery; D011859:Radiography