Sex dimorphism of the sacroiliac joint and its relation to joint mobility and function (919.14)

Abstract

The pelvic girdle is the functional connection between the spine and lower limbs, with the sacroiliac joint (SIJ) serving as the articular connection between the spine and hip bones. The SIJ provides load transfer between the axial and appendicular skeleton. It is specifically adapted to deal with these loads by both fibrous structures and morphological characteristics, which allow only limited movement. There is a sex dimorphism in the SIJ in terms of structure and function, with males having a rougher surface compared to females and a lower prevalence of pelvic girdle pain (PGP). There is also a discrepancy between the sexes pertaining to function, with females typically experiencing more issues relating to mobility. The purpose of this study is to compare SIJ articular morphology of males and females through validated measurement. 10 male and 7 female pelvises from embalmed cadavers were dissected and the SIJ opened. Digital calipers and the MicroScribe G2x tool were used to obtain surface area measurements of the joint articular surface and pelvic width dimensions. It was hypothesized that surface area will be greater in males than females, and the convexities/concavities will be more pronounced leading to a more stable joint. Dimensions will also vary between males and females affecting the overall shape of the SIJ. This would substantiate some of the differences in PGP and mobility of the joint between the sexes.