The use of alendronate to prevent early collapse of the femoral head in patients with nontraumatic osteonecrosis. A randomized clinical study.
BACKGROUND
Osteonecrosis of the femoral head is the most common diagnosis leading to total hip arthroplasty in young adults. Joint-preserving treatment options have been mainly surgical, with inconsistent results. Alendronate (a bisphosphonate agent) has been shown to lower the prevalence of vertebral compression fractures and could potentially retard the collapse of an osteonecrotic femoral head. The purpose of this study was to test the effect of alendronate in preventing early collapse of the femoral head in patients with nontraumatic osteonecrosis.


METHODS
Forty patients with Steinberg stage-II or III nontraumatic osteonecrosis of the femoral head and a necrotic area of >30% (class C) were randomly divided into alendronate and control groups of twenty patients each. Patients in the alendronate group took 70 mg of alendronate orally per week for twenty-five weeks, while the patients in the control group did not receive this medication or a placebo. The patients were observed for a minimum of twenty-four months. Harris hip scores, plain radiographs, and magnetic resonance imaging scans were obtained.


RESULTS
During the study period, only two of twenty-nine femoral heads in the alendronate group collapsed, whereas nineteen of twenty-five femoral heads in the control group collapsed (p < 0.001). One hip in the alendronate group underwent total hip arthroplasty, whereas sixteen hips in the control group underwent total hip arthroplasty (p < 0.001).


CONCLUSIONS
Alendronate appeared to prevent early collapse of the femoral head in the hips with Steinberg stage-II or IIIC nontraumatic osteonecrosis. A longer duration of follow-up is needed to confirm whether alendronate prevents or only retards collapse.


METHODS
Therapeutic Level I.
Lai
Kuo-An
KA
Orthopaedic Department, National Cheng Kung University Medical Center, No. 138 Shen-Li Road, Tainan, Taiwan. laikuoan@mail.ncku.edu.tw
Shen
Wun-Jer
WJ
Yang
Chyun-Yu
CY
Shao
Chung-Jung
CJ
Hsu
Jui-Ting
JT
Lin
Ruey-Mo
RM
D000328:Adult; D000368:Aged; D019386:Alendronate / Q000627:therapeutic use*; D001847:Bone Diseases / Q000209:etiology / Q000517:prevention & control; D004164:Diphosphonates / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D005271:Femur Head Necrosis / Q000150:complications / Q000188:drug therapy* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D004164:Diphosphonates; D019386:Alendronate