title: Sensitivity and specificity of CT- and MRI-scanning in evaluation of occult fracture of the proximal femur.
abstract: OBJECTIVE
  To estimate sensitivity and specificity of CT and MRI examinations in patients with fractures of the proximal femur. To determine the interobserver agreement of the modalities among a senior consulting radiologist, a resident in radiology and a resident in orthopaedics surgery.
  
  
  METHODS
  67 patients (27 males, 40 females, mean age 80.5) seen in the emergency room with hip pain after fall, inability to stand and a primary X-ray without fracture were evaluated with both CT and MRI. The images were analysed by a senior consulting musculoskeletal radiologist, a resident in radiology and a resident in orthopaedic surgery. Sensitivity and specificity were estimated with MRI as the golden standard. Kappa value was used to assess level of agreement in both MRI and CT finding.
  
  
  RESULTS
  15 fractures of the proximal femur were found (7 intertrochanteric-, 3 femoral neck and 5 fractures of the greater trochanter). Two fractures were not identified by CT and four changed fracture location. Among those, three patients underwent surgery. Sensitivity of CT was 0.87; 95% CI [0.60; 0.98]. Kappa for interobserver agreement for CT were 0.46; 95% CI [0.23; 0.76] and 0.67; 95% CI [0.42; 0.90]. For MRI 0.67; 95% CI [0.43; 0.91] and 0.69; 95% CI [0.45; 0.92].
  
  
  CONCLUSIONS
  MRI was observed to have a higher diagnostic accuracy than CT in detecting occult fractures of the hip. Interobserver analysis showed high kappa values corresponding substantial agreement in both CT and MRI.
authors.affiliation: Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology and Institute of Clinical Research, University of Southern Denmark, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark. Electronic address: martinhaubro@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Haubro
authors.affiliation: Musculoskeletal section, Department of Radiology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: C
authors.initials: C
authors.lastname: Stougaard
authors.affiliation: Musculoskeletal section, Department of Radiology, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Torfing
authors.affiliation: Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology and Institute of Clinical Research, University of Southern Denmark, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Overgaard
mesh_terms: D000058:Accidental Falls; D000369:Aged, 80 and over; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005596:Fractures, Closed / Q000175:diagnosis* / Q000473:pathology; D006620:Hip Fractures / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
keywords: CT; Interobserver agreement; Occult fracture proximal femur; Occult hip fracture; Sensitivity; Specificity MRI