title: The anterior inferior iliac spine: size, position, and location. An anthropometric and sex survey.
abstract: OBJECTIVE
  The purpose of this study was to investigate and describe the size, location, and position of the anterior inferior iliac spine (AIIS) in normal individuals.
  
  
  METHODS
  We reviewed 50 computed tomography (CT) scans of 50 patients without hip pain or pathologic features. Mean patient height was 169.8 cm (women, 163 cm; men, 176.8 cm) and mean weight was 69.6 kg (women, 63.8 kg; men, 75.4 kg). We used all scans to measure both the left and right AIIS for the anatomic description of 100 AIISs. We measured AIIS dimensions, specifically length, width, and height. We also measured vertical, horizontal, and straight distances between the most anteroinferior prominence of the AIIS and the acetabular rim. We normalized AIIS size and distances from the acetabular rim according to the patient's height and body mass index (BMI). We also assessed the version of the AIIS using 2 angles. The first angle was the angle between the AIIS midaxis line and a plumb line, and the second angle was calculated as the angle subtended by the AIIS midaxis line and the ilium midaxis line.
  
  
  RESULTS
  There were no significant differences between the AIIS in men and women in all measurements (except the width of the AIIS) when normalized to the patient's height and BMI. There were no significant differences in AIIS dimensions when comparing side-to-side differences in the entire study population.
  
  
  CONCLUSIONS
  In quantifying AIIS dimensional size, distance from the anterior acetabular rim, and version, this study found no significant difference in all measurements normalized to patient size (height and BMI) between the left and right sides, and no significant sex difference was found in AIIS measurements, except the width of the AIIS.
  
  
  CONCLUSIONS
  Morphologic variations that deviate from these normal values may help the clinician identify cases of subspinal impingement.
authors.affiliation: Department of Orthopedics, Tel Aviv Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. eyalamar73@gmail.com
authors.forename: Eyal
authors.initials: E
authors.lastname: Amar
authors.forename: Ido
authors.initials: I
authors.lastname: Druckmann
authors.forename: Gideon
authors.initials: G
authors.lastname: Flusser
authors.forename: Marc R
authors.initials: MR
authors.lastname: Safran
authors.forename: Moshe
authors.initials: M
authors.lastname: Salai
authors.forename: Ehud
authors.initials: E
authors.lastname: Rath
mesh_terms: D000328:Adult; D000886:Anthropometry; D005260:Female; D006801:Humans; D007085:Ilium / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008297:Male; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult