ePoster #719 - ISHA Annual Scientific Meeting 2016

Adolescent Femoroacetabular Impingement (FAI): Gender Differences In Hip Morphology

Perry Hooper, DO, Warrensville Heights, OH UNITED STATES
Sameer Oak, MS, Cleveland, OH UNITED STATES
Gehan Ibrahim, MD, Columbus, OH UNITED STATES
T. Sean Lynch, MD, New York, NY UNITED STATES
Ryan Goodwin, MD, Cleveland, OH UNITED STATES
James Rosneck, MD, Garfield Heights, OH UNITED STATES

Cleveland Clinic, Cleveland, Ohio, UNITED STATES

FDA Status Not Applicable

Summary: In adolescents with FAI, distinct differences between sexes were seen on both preoperative imaging and at the time of hip arthroscopy.


Purpose: To compare the hip morphology of adolescent males and females who underwent hip arthroscopy for FAI and determine if gender differences exist.

Methods: We retrospectively reviewed the records of 177 adolescents, 13 to 18 years of age, who were treated for FAI with hip arthroscopy. We examined and analyzed preoperative MRI and plain radiographs, measuring lateral center edge angle, Tonnis angle, and alpha angle. The intraclass correlation coefficient between readers was calculated. We created multiple linear regression models incorporating age, gender and BMI with the radiographic measurements. Intraoperative findings utilizing the Outerbridge grading system were documented as well as procedure performed. We compared these findings with our preoperative imaging measurements using the Chi-squared test and the Wilcoxon rank-sum test.

Results: The intraclass correlation coefficient demonstrated moderate to strong agreement between the three image readers. The BMI and age adjusted mean alpha angle was higher in males than females on both plain radiograph (55.9° versus 45.2°; p < 0.0001) and axial oblique MRI (54.1° versus 42.5°; p < 0.0001). 38.9% of males demonstrated an alpha angle of > 55° compared to only 1% of females (p<0.0001). The lateral center edge angle and Tonnis angle on MRI and plain radiograph displayed no statistically significant differences between genders after controlling for BMI and age. Males were more likely to have chondral damage intraoperatively (56.3% versus 32.5%; p=0.0041).

Conclusions: Distinct differences between sexes were seen on both preoperative imaging and at the time of hip arthroscopy. We found that males with FAI displayed a larger mean alpha angle, and therefore a more severe cam-type deformity, than females. Our study also found that males are more likely to show evidence of chondral damage than females at the time of surgery.

Level of Evidence: IV