title: A quantitative analysis of hip capsular thickness.
abstract: OBJECTIVE
  The purpose of this study was to provide a comprehensive quantitative analysis of capsular thickness adjacent to the acetabular rim in clinically relevant locations.
  
  
  METHODS
  Dissections were performed and hip capsular measurements were recorded on 13 non-paired, fresh-frozen cadaveric hemi-pelvises using a coordinate measuring device. Measurements were taken for each clock-face position at 0, 5, 10 and 15 mm distances from the labral edge.
  
  
  RESULTS
  The capsule was consistently thickest at 2 o'clock for each interval from the labrum with a maximum thickness of 8.3 at 10 mm [95 % CI 6.8, 9.8] and 15 mm [95 % CI 6.8, 9.7]. The capsule was noticeably thinner between 4 and 11 o'clock with a minimum thickness of 4.1 mm [95 % CI 3.3, 4.9] at 10 o'clock at the labral edge. Direct comparison between 0 and 5 mm between 9 and 3 o'clock showed that the hip capsule was significantly thicker at 5 mm from the labrum at 9 o'clock (p = 0.027), 10 o'clock (p = 0.032), 1 o'clock (p = 0.003), 2 o'clock (p = 0.001) and 3 o'clock (p = 0.001).
  
  
  CONCLUSIONS
  The hip capsule was thickest between the 1 and 2 o'clock positions for all measured distances from the acetabular labrum and reached its maximum thickness at 2 o'clock, which corresponds to the location of the iliofemoral ligament.
authors.affiliation: Department of BioMedical Engineering, Steadman Philippon Research Institute, 181 West Meadow Drive Suite 1000, Vail, CO, 81657, USA, MJP@sprivail.org.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Philippon
authors.forename: Max P
authors.initials: MP
authors.lastname: Michalski
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Campbell
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Rasmussen
authors.forename: Mary T
authors.initials: MT
authors.lastname: Goldsmith
authors.forename: Brian M
authors.initials: BM
authors.lastname: Devitt
authors.forename: Coen A
authors.initials: CA
authors.lastname: Wijdicks
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology; D004210:Dissection; D006621:Hip Joint / Q000033:anatomy & histology*; D006801:Humans; D017746:Joint Capsule / Q000033:anatomy & histology*; D008023:Ligaments, Articular / Q000033:anatomy & histology; D008875:Middle Aged