title: Revision hip arthroplasties with use of the modular S-ROM prosthesis.
abstract: OBJECTIVE
  The aim of this study was to revision hip arthroplasties in ankylosing spondylitis.
  
  
  METHODS
  We performed 21 revision hip arthroplasty in 16 patients with ankylosing spondylitis (AS) using S-ROM modular femoral stem. At the final follow-up, all patients were able to ambulate without any walking aids.
  
  
  RESULTS
  The mean Harris hip score improved from 57.2 (35 to 74) pre-operatively to 90.2 points (73 to 100) post-operatively, and the outcome was classified as good or excellent in 17 hips (81%). Fixation of the femoral component was classified as stable with bone ingrowth in 15 hips (71.4%), stable with fibrous ingrowth in 2 hips (9.5%), and radiolucent loosening in 4 hips (19.1%). Five hips developed a pedestal at the tip of femoral component. Femoral osteolysis was found in 3 hips (14.2%): 3 hips in Gruen zones 1 and 7, one hip in zone 7, and two hips in zone 1. One hip underwent acetabular revision because of breakage of polyethylene liner, and the well-fixed femoral component was left in situ. Thigh pain developed in 1 patient (6.2%). Kaplan-Meier survival was 81% at 64 months, with radiographic loosening as an end-point when two hips were at risk.
  
  
  CONCLUSIONS
  Satisfactory results of midterm clinical and radiographic follow-up can be achieved using S-ROM modular femoral stem for revision of femoral stem in ankylosing spondylitis.
authors.affiliation: Department of Orthopedic Surgery, The Fourth Affiliated Hospital, Harbin Medical University, China.
authors.forename: Yong-Yun
authors.initials: YY
authors.lastname: Lian
authors.forename: Qi
authors.initials: Q
authors.lastname: Yue
authors.forename: Wei-Jie
authors.initials: WJ
authors.lastname: Yue
authors.forename: Chen-Bin
authors.initials: CB
authors.lastname: Zhao
authors.forename: Qing-Gang
authors.initials: QG
authors.lastname: Meng
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D020099:Coated Materials, Biocompatible; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D020099:Coated Materials, Biocompatible