Open AccessDecreasing pelvic incidence is associated with greater risk of cam morphology
Author(s) -
William Z. Morris,
Cody A. Fowers,
Roger Yuh,
Jeremy J. Gebhart,
Michael J. Salata,
R. W. Liu
Publication year - 2016
Publication title -
bone and joint research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.639
H-Index - 31
ISSN - 2046-3758
DOI - 10.1302/2046-3758.59.bjr-2016-0028.r1
Subject(s) - pelvic tilt , medicine , incidence (geometry) , femoroacetabular impingement , cohort , pelvis , cadaveric spasm , sagittal plane , cohort study , surgery , anatomy , geometry , mathematics
Objectives The spinopelvic relationship (including pelvic incidence) has been shown to influence pelvic orientation, but its potential association with femoroacetabular impingement has not been thoroughly explored. The purpose of this study was to prove the hypothesis that decreasing pelvic incidence is associated with increased risk of cam morphology.Methods Two matching cohorts were created from a collection of cadaveric specimens with known pelvic incidences: 50 subjects with the highest pelvic incidence (all subjects > 60°) and 50 subjects with the lowest pelvic incidence (all subjects 55°. Differences between the two cohorts were analysed with a Student’s t-test and the difference in incidence of cam morphology was assessed using a chi-squared test. The significance level for all tests was set at p 60° (p = 0.002). The mean alpha angle was also greater in the cohort with pelvic incidence < 35° (mean 53.7°, sd 10.7° versus mean 49.7°, sd 10.6°; p = 0.008).Conclusions Decreased pelvic incidence is associated with development of cam morphology. We propose a novel theory wherein subjects with decreased pelvic incidence compensate during gait (to maintain optimal sagittal balance) through anterior pelvic tilt, creating artificial anterior acetabular overcoverage and recurrent impingement that increases risk for cam morphology. Cite this article: W. Z. Morris, C. A. Fowers, R. T. Yuh, J. J. Gebhart, M. J. Salata, R. W. Liu. Decreasing pelvic incidence is associated with greater risk of cam morphology. Bone Joint Res 2016;5:387–392. DOI: 10.1302/2046-3758.59.BJR-2016-0028.R1.