title: The Effect of Hydroxyapatite Coating on Long-term Results of Total Hip Arthroplasty with Hydroxyapatite-coated Anatomic Femoral Stem.
abstract: OBJECTIVE
  To evaluate the clinical and radiological results, as well as the survival rate, associated with total hip arthroplasty using a hydroxyapatite (HA)-coated anatomical femoral stem at a follow-up of ≥12 years.
  
  
  METHODS
  From April 1992 to May 1997, 86 patients (102 hips) underwent total hip arthroplasty with a HA-coated ABG I (Anatomical Benoist Giraud; Howmedica) hip prosthesis. The average age at the time of surgery was 53.4 years and the mean duration of follow-up was 17.1 years (range, 12.1-21.0 years). The Harris hip score (HHS) and radiographic assessments of thigh pain were used to evaluate the clinical results. We observed osteointegration, cortical hypertrophy, reactive line, calcar resorption and osteolysis around the femoral stems. The survival rate of the femoral stems was evaluated by using the span of time to a revision operation for any reasons was defined as the end point.
  
  
  RESULTS
  The mean HHS was 50.5 preoperatively and 84.2 at the time of last follow-up. Osteolysis only around the HA-coated proximal portion of the femoral stem was observed in 72 hips, cortical hypertrophy all around the distal portion of the femoral stem was observed in 38 hips, and calcar resorption was observed in 44 hips. A reactive line was observed in 13 hips, but was unrelated to component loosening. Stem revision operations were performed in 24 (23%) hips due to osteolysis (14 hips), fracture (5 hips) and infection (5 hips). The femoral stem survival rate was 75% over the mean duration of follow-up.
  
  
  CONCLUSIONS
  Total hip arthroplasty using a HA-coated anatomical femoral stem showed necessitated a high rate of revision operations due to osteolysis around the femoral stem in this long term follow-up study.
authors.affiliation: Department of Orthopaedic Surgery, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Young-Yool
authors.initials: YY
authors.lastname: Chung
authors.affiliation: Department of Orthopaedic Surgery, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Chae-Hyun
authors.initials: CH
authors.lastname: Im
authors.affiliation: Department of Orthopaedic Surgery, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Ju-Yeong
authors.initials: JY
authors.lastname: Heo
authors.affiliation: Department of Orthopaedic Surgery, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Jang
keywords: Anatomical femoral stem; Hydroxyapatite coating; Total hip arthroplasty