title: Scintigraphic assessment of the rotated femoral head after transtrochanteric rotational osteotomy for osteonecrosis.
abstract: BACKGROUND
  The purpose of this study was to assess the usefulness of bone scintigraphy in predicting progressive collapse of the femoral head after transtrochanteric rotational osteotomy for the treatment of osteonecrosis of the femoral head.
  
  
  METHODS
  We studied thirty-three hips in thirty patients with osteonecrosis of the femoral head who had undergone transtrochanteric rotational osteotomy. There were twenty male and ten female patients, with a mean age of 34.4 years at the time of the operation. The mean duration of follow-up was 10.0 years. According to the staging system of Ficat and Arlet, there were nineteen stage-2 hips and fourteen stage-3 hips at the time of the operation. Conventional anteroposterior and lateral radiographs were assessed. In addition, bone scans were performed at three weeks after the operation to predict the outcome with regard to the rotated femoral head. On the basis of the location of low scan activity within the femoral head, the scintigraphic findings were classified into one of two categories: type A if there was no low scan activity in the weight-bearing area of the femoral head or type B if low scan activity occupied the entire weight-bearing area. Six hips with collapse were studied histologically.
  
  
  RESULTS
  Postoperative scintiscans revealed sixteen type-A hips and seventeen type-B hips. Of the type-A hips, only three exhibited progressive collapse of the femoral head after the osteotomy, whereas fourteen of the type-B hips exhibited progressive collapse. A significant association was found between the postoperative scintigraphic findings and the final radiographic result (p < 0.01).
  
  
  CONCLUSIONS
  Bone scintiscans made three weeks after transtrochanteric rotational osteotomy were useful for predicting the final clinical result.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Medical School, Suita, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakai
authors.forename: K
authors.initials: K
authors.lastname: Masuhara
authors.forename: T
authors.initials: T
authors.lastname: Nakase
authors.forename: N
authors.initials: N
authors.lastname: Sugano
authors.forename: K
authors.initials: K
authors.lastname: Ohzono
authors.forename: T
authors.initials: T
authors.lastname: Ochi
mesh_terms: D000328:Adult; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging*; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010027:Osteotomy; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D013669:Technetium Tc 99m Medronate; D013997:Time Factors; D016474:Weight-Bearing
chemical_list: D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate