DETERMINING THE EFFECT OF SEX ON FCT CHANGES FOLLOWING DROP JUMPING ACTIVITIES IN HEALTHY INDIVIDUALS

Abstract

Previous research indicates that female’s cartilage responds to both applied loads and injury differently than male’s cartilage. Determining if this is true and why this might be the case will play an important role in understanding the development of osteoarthritis as well as the treatment of patients post-surgically. The purpose of this study was to determine the effect of sex on FCT changes following drop jumping activities in healthy individuals. Participants had 4 control ultrasound images taken of each knee to establish a baseline thickness of their femoral cartilage, followed by two series of 10 drop landings from a 30 cm platform. After each set of drop landings, 3 more images were taken of each knee. All images were analyzed using an external computer software program, Horos, to measure the thickness of the femoral cartilage across three different regions: medial, intercondylar, and lateral. Mixed Model ANOVAs with repeated measures on condition (3) and a between factor of sex were performed. Male’s cartilage was found to be significantly thicker (p=.005) than female’s when averaging each of the five measured points: x̄males = 2.259 mm, 95% CI [2.049, 2.468] and x̄females = 1.832 mm, 95% CI [1.676, 1.989]. There was no significant change in cartilage thickness across the conditions (p =.599) and there was no sex by condition interaction (p=.497) with an observed power of 0.216. We expected to see some difference in the way that males’ and females’ cartilage adapted throughout the trials, and it is possible that the reason we did not see the expected results because the stimulus of 10 drop landings for a 30 cm platform is not great enough to cause a decrease in cartilage thickness. This protocol, however, was designed to be a more realistic representation of the stresses that someone might encounter in their daily life, and thus may not be able to fully represent the adaptability of cartilage under greater amounts of loading. If future studies find conclusive evidence to say that sex has an impact of femoral cartilage thickness adaptations, further studies should be done to determine if it is possible to change the movement patterns of one of the sexes to reduce the probability of dangerous load being placed on the knee. Understanding these differences might in the future play a role in understanding the development of osteoarthritis as well as the treatment of patients post surgically.