Anatomical variations of the sacroiliacal joint

Abstract

IntroductionThe sacroiliac joint (SIJ) is the union between the spine and the pelvis. It is a diarthroid joint and complex due to having different types of joint classifications. The presence of an accessory articular facet was described for the first time in 1753, considered the first report of a sacroiliac anatomical variant. Since then different anatomists have reported this variant in skeletons and corpses with variations in their incidence. In 1999, the first classification was made using a Greek population reporting 5 other anatomical variants using computed tomography (CT) and correlating this to lumbar pain, reporting a high incidence when anatomical variants were present. Only one other study analyzes the joint using this classification in a Turkish population. There are no reports of other population, much less Latin American. Our aim was to identify the prevalence of SIJ anatomical variants using CT.Materials and methodsA retrospective study was made based on pelvic and/or abdominal CT that allowed the complete visualization of the SIJ. SIJ space was measured, and variants were classified as: Accessory SIJ, ileosacro complex, bipartite bone plate, semicircular defect, iliac bone plate, and ossification center.ResultsFour hundred CT scans were included for analysis. The mean age was 49 years, 180 (45%) were men and 220 (55%) women. More than half (209, 52.2%) of the patients presented an anatomical variant, and were more predominant in women (65.4% vs 36.2%), as well as those older than 40 years of age (60% vs 40%). The mean joint space was similar between sides (right 2.41 ± 0.65mm vs. left 2.37 ± 0.65mm). Incidence was 19.8% accessory SIJ, 6.5% ileosacro complex, 12.3% bipartite bone plate, 8% semicircular defect, 5% iliac bone plate, and 0.8% for ossification center. No statistically significant differences were found comparing the space with the variables of gender, age, or type of variant.ConclusionThe prevalence of anatomical variants of the SIJ is high in the Latin population, higher in women and those older than 40 years. The most prevalent variant was accessory SIJ.Support or Funding InformationNoneThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.