title: Detection of prefracture hip lesions in atypical subtrochanteric fracture with dual-energy x-ray absorptiometry images.
abstract: OBJECTIVE
  To retrospectively assess how often and how early hip dual-energy x-ray absorptiometry (DXA) images show prefracture lesions in patients with atypical subtrochanteric fracture (ASF) and determine whether DXA images with assessment of prodromal symptoms could be used for early ASF prediction.
  
  
  METHODS
  The retrospective research protocol complied with HIPAA and was institutional review board approved, with waiver of informed consent. Among 62 women with ASF, nine without hip DXA images and seven without clear documentation of prodromal symptoms were excluded. Serial DXA images of 52 hips in 46 patients were included. Among them, 33 hips were assessed with ipsilateral DXA. For this ipsilateral group, each hip was assessed for prodromal symptoms and focal cortical changes in the lateral subtrochanteric femur cortex at DXA. Overall and cumulative detection rates for prodromal symptoms, DXA, and DXA with prodromal symptoms were measured and compared with a general linear model for overall detection rate and Cox proportional hazard models for cumulative detection rate. Thirty-three representative ipsilateral images and 199 images from subjects without fractures were reviewed in random order for prefracture lesions by three musculoskeletal radiologists independently, and the performance of DXA in ASF prediction was assessed.
  
  
  RESULTS
  Overall detection rates for DXA, prodromal symptoms, and DXA with prodromal symptoms were 61% (20 of 33), 42% (14 of 33), and 73% (24 of 33), respectively, in the ipsilateral group. Overall detection rate comparisons showed that DXA with prodromal symptoms was superior to prodromal symptoms alone (P = .0377). The cumulative detection rate curve for DXA with prodromal symptoms was also superior to that of prodromal symptoms alone (P = .0018). Sensitivity and specificity of DXA in ASF prediction ranged from 52% (17 of 33) to 58% (19 of 33) and 99% (197 of 199) to 100% (199 of 199), respectively.
  
  
  CONCLUSIONS
  Assessment of hip DXA images combined with conventional assessment of prodromal symptoms enables detection of more ASFs earlier than assessment based on prodromal symptoms alone.
authors.affiliation: From the Depts of Radiology (S.K.) and Orthopedic Surgery (K.H.Y.), Gangnam Severance Hosp, Yonsei Univ College of Medicine, 211 Eonju-ro, Gangnam-Gu, Seoul 135-720, South Korea; Biostatistics Collaboration Unit, Gangnam Severance Hosp, Biomedical Research Ctr, Yonsei Univ College of Medicine, Seoul, South Korea (H.L.); Dept of Orthopedic Surgery, Seoul National Univ Bundang Hosp, Sungnam-si, South Korea (Y.K.L.); Dept of Orthopedic Surgery, National Health Insurance Corporation Ilsan Hosp, Goyang, South Korea (H.K.Y.); Dept of Orthopedic Surgery, Kyungpook National Univ Hosp, Daegu, South Korea (C.W.O.); Depts of Orthopedic Surgery (K.K.P.) and Radiology (Y.H.L.), Severence Hospital, Yonsei University College of Medicine, Seoul, South Korea; Dept of Orthopedic Surgery, Keimyung Univ Dongsan Medical Ctr, Daegu, South Korea (B.W.M.); Dept of Radiology, Hanyang Univ Guri Hosp, Hanyang Univ, Guri, South Korea (J.A.R.); and Dept of Radiology, Ajou Univ Hosp, Ajou Univ School of Medicine, Uwon, South Korea (K.S.K.).
authors.forename: Sungjun
authors.initials: S
authors.lastname: Kim
authors.forename: Kyu Hyun
authors.initials: KH
authors.lastname: Yang
authors.forename: Hyunsun
authors.initials: H
authors.lastname: Lim
authors.forename: Young-Kyun
authors.initials: YK
authors.lastname: Lee
authors.forename: Han Kook
authors.initials: HK
authors.lastname: Yoon
authors.forename: Chang-Wug
authors.initials: CW
authors.lastname: Oh
authors.forename: Kwan Kyu
authors.initials: KK
authors.lastname: Park
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Min
authors.forename: Jeong Ah
authors.initials: JA
authors.lastname: Ryu
authors.forename: Kyu-Sung
authors.initials: KS
authors.lastname: Kwack
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D042241:Early Diagnosis; D005260:Female; D006620:Hip Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors