title: Total hip replacement using a highly crosslinked polyethylene liner in Asians with small acetabulum.
abstract: OBJECTIVE
  To evaluate the medium-term outcomes of total hip replacement (THR) using a thin highly cross-linked polyethylene (HXLPE) liner in an Asian population.
  
  
  METHODS
  Medical records of 20 men and 44 women aged 26 to 80 (mean, 59) years who underwent 80 THRs using a thin HXLPE liner by a single surgeon were reviewed. Indications for THR included dysplasia (n = 26), avascular necrosis (n=26), osteoarthritis (n = 22), rheumatoid arthritis (n = 4), and ankylosing spondylitis (n = 2). The surgical technique, implant used, and rehabilitation protocol were standardised. Radiographs were evaluated for cup migration and peri-implant radiolucency. Femoral head penetration was assessed at day 1 and last follow-up using the Kang modification of the Dorr and Wan method and the PowerPoint method.
  
  
  RESULTS
  After a mean follow-up of 7.5 (range, 5.0-11.9) years, no patient had undergone acetabular revision. Two hips were revised for the femoral stem. Femoral head penetration did not correlate with sex, age at surgery, hip pathology, acetabular inclination angle, cup size, or liner thickness. The maximum femoral head penetration was 0.09 mm/year, which was below the osteolysis threshold of 0.1 mm/year. The mean ± standard deviation femoral head penetration was 0.29 ± 0.12 mm (or 0.04 ± 0.02 mm/year) by the PowerPoint method and 0.17 ± 0.22 mm (or 0.02 ± 0.03 mm/year) by the Kang modification of the Dorr and Wan method. Femoral head penetration correlated with the number of years of follow-up (p = 0.012).
  
  
  CONCLUSIONS
  The use of a thin HXLPE liner in primary THR for patients with small acetabulum achieved good outcomes after a mean of 7.5 years.
authors.affiliation: National University Hospital, Singapore.
authors.forename: Weiliang
authors.initials: W
authors.lastname: Chua
authors.forename: Shuvendu
authors.initials: S
authors.lastname: Roy
authors.forename: Jonathan
authors.initials: J
authors.lastname: Sng
authors.forename: Shen
authors.initials: S
authors.lastname: Liang
authors.forename: Shamal Das
authors.initials: SD
authors.lastname: De
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D044466:Asian People; D001672:Biocompatible Materials; D005260:Female; D005500:Follow-Up Studies; D006621:Hip Joint / Q000033:anatomy & histology / Q000601:surgery*; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020959:Polyethylene; D011474:Prosthesis Design; D012189:Retrospective Studies
chemical_list: D001672:Biocompatible Materials; D020959:Polyethylene
keywords: arthroplasty, replacement, hip; osteolysis; polyethylene