Evaluation of bipolar hemiarthroplasty for the treatment of steroid-induced osteonecrosis of the femoral head.
OBJECTIVE
Bipolar hemiarthroplasty (BHA) for idiopathic osteonecrosis of the femoral head (ONFH) is performed at our institution. The purpose of this study was to evaluate the clinical and radiographic findings after BHA for the treatment of steroid -induced ONFH.


METHODS
Thirty-seven hips in 27 patients were assessed (seven men, 11 hips; 20 women, 26 hips), average patient age at the time of surgery of 42.6 (range 20-83) years, with steroid-induced ONFH treated with BHA between 1995 and 2005. The mean follow-up duration was approximately ten (range five to 15) years. Patients were evaluated according to the Japan Orthopaedic Association (JOA) hip score. Kaplan-Meier survivorship was calculated to examine revision arthroplasty failure rate. Radiographic analysis of loosening included radiolucent lines and osteolysis of the acetabulum or femur. Causes of loosening were analysed using multiple logistic regression.


RESULTS
JOA hip score increased from 53 points (preoperative) to 87 points (final follow-up). Survival rates were 96.8 % and 78.6 % at ten and 15 years, respectively. Prosthesis loosening occurred on the acetabular side in five hips (13.5 %). No femoral-component loosening was observed. BHA had poor results in patients with Association Research Circulation Osseous (ARCO) stage IV ONFH and in patients under 40 years of age.


CONCLUSIONS
BHA, with strict surgical indications, may be a good option for treating ONFH. Based on these results, total hip arthroplasty is recommended for patients with ARCO stage IV ONFH or for patients under 40 years of age.
Department of Orthopaedic Surgery, School of Medicine, Kitasato University, 1 -15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan. moriya0425@gmail.com
Mitsutoshi
M
Moriya
Katsufumi
K
Uchiyama
Naonobu
N
Takahira
Kensuke
K
Fukushima
Takeaki
T
Yamamoto
Keika
K
Hoshi
Moritoshi
M
Itoman
Masashi
M
Takaso
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005271:Femur Head Necrosis / Q000139:chemically induced* / Q000503:physiopathology / Q000601:surgery*; D005938:Glucocorticoids / Q000009:adverse effects*; D062785:Hemiarthroplasty / Q000009:adverse effects / Q000379:methods*; D006621:Hip Joint / Q000503:physiopathology / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology; D011788:Quality of Life; D016059:Range of Motion, Articular; D012307:Risk Factors; D015996:Survival Rate; D055815:Young Adult
D005938:Glucocorticoids