Sex-dependent Relationship Between Wrist Deviation and Scaphoid Kinematics

Several methods of describing patterns of carpal kinematics from radiographs have emerged due to their potential use in developing personalized treatments for wrist pathologies. Such radiography-derived metrics have been used to infer associations between patterns of scaphoid kinematics and other clinically relevant factors such as sex, but the simultaneous effects of sex and wrist position on scaphoid kinematic metrics has yet to be considered. We sought to investigate the relationship between wrist position in the coronal plane and radiographic measurements of the scaphoid for each sex independently, then identify sex-specific differences in scaphoid measurements and calculated metrics. We retrospectively identified 38 subjects with posteroanterior radial and ulnar deviation radiographs. Radiographic scaphoid measurements were collected and used to calculate five scaphoid kinematic metrics per participant. We used Pearson correlation coefficients to explore the relationships between the degrees of wrist deviation in the coronal plane and radiographic scaphoid measurements for men and women independently. We used the non-parametric Wilcoxon signed-rank test to compare values between sexes. The correlations between degrees of coronal wrist deviation and radiographic measurements of scaphoid inclination were significant only for men. Men also had significantly greater values for all radiographic scaphoid measurements. Our study demonstrated sex-specific differences in the relationship between the degrees of radial and ulnar wrist deviation and scaphoid positioning. These results show the importance of stratifying by sex in studies of carpal kinematics, such as scaphoid kinematics, and that investigation of strategies to restore normal carpal function should incorporate sex as a biological variable.