title: Computed tomography arthrography with traction in the human hip for three-dimensional reconstruction of cartilage and the acetabular labrum.
abstract: OBJECTIVE
  To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum.
  
  
  METHODS
  Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patients after periacetabular osteotomy surgery, and 25 subjects with normal anatomy. Fifteen to 25 ml of contrast agent diluted with lidocaine was injected using a lateral oblique approach. A Hare traction splint applied traction during CT. The association between traction force and intra-articular joint space was assessed qualitatively under fluoroscopy. Cartilage geometry was reconstructed from the CTA images for 30 subjects; the maximum joint space under traction was measured.
  
  
  RESULTS
  Using the Hare traction splint, the intra-articular space and boundaries of cartilage could be clearly delineated throughout the joint; the acetabular labrum was also visible. Dysplastic hips required less traction (∼5 kg) than normal and retroverted hips required (>10 kg) to separate the cartilage. An increase in traction force produced a corresponding widening of the intra-articular joint space. Under traction, the maximum width of the intra-articular joint space during CT ranged from 0.98-6.7 mm (2.46 ± 1.16 mm).
  
  
  CONCLUSIONS
  When applied to subjects with normal and abnormal hip anatomy, the CTA protocol presented yields clear delineation of the cartilage and the acetabular labrum. Use of a Hare traction splint provides a simple, cost-effective method to widen the intra-articular joint space during CT, and provides flexibility to vary the traction as required.
authors: Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA.
authors: C R
authors: CR
authors: Henak
authors: Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
authors: C L
authors: CL
authors: Abraham
authors: Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
authors: C L
authors: CL
authors: Peters
authors: Department of Radiology, University of Utah, Salt Lake City, UT, USA.
authors: R K
authors: RK
authors: Sanders
authors: Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
authors: J A
authors: JA
authors: Weiss
authors: Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA; Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA. Electronic address: Andrew.Anderson@hsc.utah.edu.
authors: A E
authors: AE
authors: Anderson
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging*; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001175:Arthrography / Q000379:methods*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006617:Hip Dislocation / Q000000981:diagnostic imaging / Q000601:surgery; D006621:Hip Joint / Q000002:abnormalities / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D013165:Splints; D014057:Tomography, X-Ray Computed / Q000379:methods; D014143:Traction / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media