title: The timing of bone SPECT to predict osteonecrosis after internal fixation of femur neck fractures.
abstract: BACKGROUND
  Bone SPECT can be used after a femur neck fracture to assess the circulation of the femoral head in the immediate postoperative period because the blood supply is one of the major factors affecting bone uptake of radiotracer on bone scintigraphy. The purpose of our present study was to investigate whether osteonecrosis of the femoral head (OFH) after internal fixation of femoral neck fracture could be predicted by early and late bone SPECT.
  
  
  METHODS
  This retrospective cohort study enrolled 44 patients (33 women; mean age, 66.9 years) who underwent surgical fixation for femoral neck fractures. Early and late bone SPECT images were obtained within 2 weeks postoperatively and at 3 months postoperatively. Patients were followed up for a minimum of 24 months (average, 34 months).
  
  
  RESULTS
  OFH developed in 9 out of 44 patients but no patient showed nonunion. Seventeen patients with normal femoral head uptake on early bone SPECT were healed. Of 27 patients with decreased femoral head uptake on early bone SPECT, 2 patients developed OFH on radiography before 3 months postoperatively, 18 patients recovered to normal uptake on the late SPECT, and the remaining 7 patients still showed decreased uptake on the late SPECT at 3 months postoperatively. All of these 7 cases finally developed OFH on radiography.
  
  
  CONCLUSIONS
  Bone SPECT can reliably predict the possibility of OFH with after femoral neck fracture at least 3 months after surgery, while early bone SPECT showed low specificity.
  
  
  METHODS
  Clinical.
authors.affiliation: Department of Orthopedic Surgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Ji Wan
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Jin-Sook
authors.initials: JS
authors.lastname: Ryu
authors.affiliation: Department of Nuclear Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sora
authors.initials: S
authors.lastname: Baek
authors.affiliation: Department of Orthopedic Surgery, CHA Bundang Medical Center, CHA University, Republic of Korea.
authors.forename: Seong-Eun
authors.initials: SE
authors.lastname: Byun
authors.affiliation: Department of Orthopaedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: jschang@amc.seoul.kr.
authors.forename: Jae Suk
authors.initials: JS
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws / Q000009:adverse effects; D042241:Early Diagnosis; D005260:Female; D005265:Femoral Neck Fractures / Q000175:diagnosis / Q000601:surgery*; D005271:Femur Head Necrosis / Q000175:diagnosis* / Q000209:etiology; D005272:Femur Neck / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000601:surgery; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D011237:Predictive Value of Tests; D011859:Radiography / Q000379:methods; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*