title: Effect of pelvic inclination and torsional deformity on canine acetabular morphology with computed tomography. A phantom study.
abstract: OBJECTIVE
  To evaluate how the inclination and torsional deformity of the hemipelvis using extra-rotation as a model affect acetabular angle (AA) and dorsal acetabular rim angle (DARA) assessment with computed tomography (CT).
  
  
  METHODS
  A normal canine hemipelvis positioned in dorsal recumbency was scanned with a 16-slice multidetector CT scanner, with different degrees of torsional deformity, using extra-rotation around the long axis (0-5-10-15°) of the hemipelvis. Each degree of extra-rotation was acquired at 0°, +20° and -20° of gantry tilt, to mimic different pelvic inclinations on its transverse axis. Cranial and central individual acetabular angles (IAA) and central DARA were calculated and correlated with inclination and torsional deformity.
  
  
  RESULTS
  A very strong negative correlation was found between cranial and central IAA, pelvic inclination, and torsional deformity. A very strong positive correlation was found between DARA, pelvic inclination, and torsional deformity.
  
  
  CONCLUSIONS
  Pelvic inclination and torsional deformity affect acetabular angles assessment with CT. The greater the inclination (ilia far from the tabletop in dorsal recumbency) and torsional deformity of the pelvis, the worse the acetabulum appeared. A standardized scanning protocol for acetabular morphology assessment is needed and it should consider pelvic inclination. The actual relevance of pelvic torsional deformity is not well known and it should be investigated more thoroughly.
authors.affiliation: Giacomo Gnudi, Via del Taglio 10, 43100 Parma, Italy, Phone: +39 0521 032 789, Fax: +39 0521 032 791, E-mail: giacomo.gnudi@unipr.it.
authors.forename: A
authors.initials: A
authors.lastname: Volta
authors.forename: A
authors.initials: A
authors.lastname: Palumbo Piccionello
authors.forename: A
authors.initials: A
authors.lastname: Salvaggio
authors.forename: F
authors.initials: F
authors.lastname: Dini
authors.forename: M
authors.initials: M
authors.lastname: Bonazzi
authors.forename: S
authors.initials: S
authors.lastname: Manfredi
authors.forename: A M
authors.initials: AM
authors.lastname: Tambella
authors.forename: G
authors.initials: G
authors.lastname: Gnudi
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging*; D000818:Animals; D004285:Dogs / Q000033:anatomy & histology*; D010388:Pelvis / Q000000981:diagnostic imaging* / Q000473:pathology*; D011859:Radiography; D014102:Torsion Abnormality / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*
keywords: Computed tomography; acetabulum; dog