title: Retroperitoneal hematoma with bone resorption around the acetabular component after total hip arthroplasty: a case report and review of the literature.
abstract: BACKGROUND
  Vascular complications related to cup-fixating screws penetrating the medial acetabular wall during total hip arthroplasty are not uncommon but rarely are associated with serious adverse events in the late post-operative period.
  
  
  METHODS
  We present the case of a 77-year-old Japanese woman who developed progressive extensive bone resorption and large hematoma in the acetabulum 13 years after total hip arthroplasty. On admission to our hospital, she was on oral warfarin (1.5mg/day) for atrial fibrillation. About 5 months after the initiation of anticoagulant therapy, she suffered a major fall followed by massive subcutaneous and pelvic girdle bleeding, predominantly on the medial side of the right thigh, but a fracture or damage of total hip arthroplasty was not evident on an emergency orthopedic evaluation. One year after the accident, a routine follow-up examination showed an asymptomatic osteolytic lesion in the acetabulum on the right pelvis, and 2 years later our patient noticed progressive pain in her right hip during walking. A large osteolytic lesion was noted in the right acetabulum on a plain radiograph. On high-resolution computed tomography and magnetic resonance imaging, a huge granulomatous lesion in the acetabulum was suggestive of chronic hematoma in intrapelvic and extrapelvic gluteal regions. A closer computed tomography examination showed that one of the screws used for fixation of the acetabular component in the total hip arthroplasty had penetrated the acetabular bone and had reached the pelvic cavity. Surgery was performed in a single session by means of two approaches: anterior midline transperitoneal address to resect the low-density mass lesion followed by posterolateral acetabular implant re-settlement.
  
  
  CONCLUSIONS
  Though rare, total hip arthroplasty-related late vascular complications could be serious and potentially affect the limb and quality of life.
authors.affiliation: Departments of Orthopaedics and Rehabilitation Medicine, Faculty of Medical Sciences, University of Fukui, Matsuoka-Shimoaizuki 23-3, Eiheiji, Fukui, 910-1193, Japan. kuchida@u-fukui.ac.jp.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Uchida
authors.forename: Kohei
authors.initials: K
authors.lastname: Negoro
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kokubo
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yayama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Miyazaki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakajima
authors.forename: Ai
authors.initials: A
authors.lastname: Yoshida
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Baba