Computed tomography osteoabsorptiometry-based investigation on subchondral bone plate alterations in sacroiliac joint dysfunction

A Poilliot,M Zhang,J Zwirner,N Hammer,M Müller-Gerbl,T Doyle,M Toranelli,D Kurosawa

doi:10.1038/s41598-021-88049-2

Abstract

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Mineralization densitograms of 27 SIJD patients and 39 controls, were obtained using CT osteoabsorptiometry. Hounsfield unit (HU) values of the SCB mineralization of superior, anterior and inferior regions on the iliac and sacral auricular surfaces were derived and statistically compared between SIJD-affected and control cohorts. Healthy controls showed higher HU values in the iliac; 868 ± 211 (superior), 825 ± 121 (anterior), 509 ± 114 (inferior), than in the sacral side; 541 ± 136 (superior), 618 ± 159 (anterior), 447 ± 91 (inferior), of all regions (p < 0.01). This was similar in SIJD; ilium 908 ± 170 (superior), 799 ± 166 (anterior), 560 ± 135 (inferior), sacrum 518 ± 150 (superior), 667 ± 151 (anterior), 524 ± 94 (inferior). In SIJD, no significant HU differences were found when comparing inferior sacral and iliac regions. Furthermore, HU values in the inferior sacral region were significantly higher when compared to the same region of the healthy controls (524 ± 94 vs. 447 ± 91, p < 0.01). Region mineralization correlated negatively with age (p < 0.01). SIJD-affected joints reflect a high mineralization of the sacral inferior region, suggesting increased SIJD-related mechanical stresses. Age-related SCB demineralization is present in all individuals, regardless of dysfunction.

Highlights

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain
As asymmetrical gait and abnormal biomechanics are typically observed in SIJD patients, likely as a compensatory m echanism[21], changes in bone mineralization patterns may reflect on the auricular surfaces caused by the abnormal loads instigated by SIJD
In the joints affected by unilateral SIJD and the contralateral unaffected sides, both the superior and the anterior regions of the ilium showed significantly higher Hounsfield units (HU) values than the same regions of the sacrum (p < 0.05; Fig. 3B,D)

Summary

Introduction

Sacroiliac joint dysfunction (SIJD) is an underappreciated source of back pain. Mineralization patterns of the sacroiliac (SIJ) subchondral bone plate (SCB) may reflect long-term adaptations to the loading of the joint. Hounsfield unit (HU) values of the SCB mineralization of superior, anterior and inferior regions on the iliac and sacral auricular surfaces were derived and statistically compared between SIJD-affected and control cohorts. In unilaterally-affected SIJD, patients often load through their unaffected side for pain-relief leading to a decrease in muscle endurance and strength on the painful side which can affect the pelvic force-closure s ystem[22,23] This given study aimed to compare the mineralization distribution patterns of the dysfunctional SCB in the superior, anterior and inferior regions of both the sacrum and the ilium, by comparing that of a cohort of SIJD patients with that of an age-matched healthy control cohort with no history of LBP. The following hypotheses were investigated: 1. SIJD patients display higher mineralization patterns compared to the healthy state

Methods

Results

Conclusion