Sacroiliac Joint Anatomy
Table of contents
Innervation
Humans
- Grob KR, Neuhuber WL, Kissling RO. Innervation of the sacroiliac joint of the human Z Rheumatol. 1995 Mar-Apr;54(2):117-22. German. Cadaveric dissections, SI joint innervation solely from dorsal rami of spinal nerves S1 to S4.
- Ikeda R. Innervation of the sacroiliac joint. Macroscopical and histological studies Nippon Ika Daigaku Zasshi. 1991 Oct;58(5):587-96. Japanese. Cadaveric dissection, ventral aspect of SI joint innervated by ventral ramus of L5 and S2, dorsal portion innervated by dorsal ramus of L5 and lateral branches of the dorsal rami of the sacral nerves.
Rats
- Murata Y, Takahashi K, Ohtori S, Moriya H. Innervation of the sacroiliac joint in rats by calcitonin gene-related peptide-immunoreactive nerve fibers and dorsal root ganglion neurons. Clin Anat. 2007 Jan;20(1):82-8. CGRP-immunoreactive (CGRP-ir) sensory nerve fibers present dorsally greater than ventrally, cranially greater than caudally. Higher frequency in the cranial, dorsal aspect of the joint.
- Murata Y, Takahashi K, Yamagata M, Takahashi Y, Shimada Y, Moriya H. Sensory innervation of the sacroiliac joint in rats. Spine. 2000 Aug 15;25(16):2015-9. Neural tracer labeling performed, ipsilateral innervation from L1-S2?, L1 and L2 sensory fibers found passing through paravertebral sympathetic trunk.
Biomechanics
- Sturesson B, Selvik G, Uden A. Movements of the sacroiliac joints. A roentgen stereophotogrammetric analysis. Spine. 1989 Feb;14(2):162-5. Roentgen stereophotogrammetry in vivo was used with subjects assuming normal and extreme physiologic positions, rotational mean between positions 2.5 degrees (0.8 degree-3.9 degrees), translational mean, 0.7 mm (0.1-1.6 mm), no difference between symptomatic and asymptomatic joints.
- Kissling RO, Jacob HA. The mobility of the sacroiliac joint in healthy subjects. Bull Hosp Jt Dis. 1996;54(3):158-64. stereophotogrammetric analysis used in vivo, rotational mean and translational mean 1.8 degrees / 0.7 mm for males and 1.9 degrees / 0.9 mm for females, no statistical difference between sexes or age.
- Wilke HJ, Fischer K, Jeanneret B, Claes L, Magerl F. In vivo measurement of 3-dimensional movement of the iliosacral joint. Z Orthop Ihre Grenzgeb. 1997 Nov-Dec;135(6):550-6. German. in vivo, 6 patients, 12 SI joints s/p Schanz screw implantation into S1 and the ilium. All sagittal rotational angles (flexion plus extension) less than 2 degrees, translation < 1 mm. Hip extension produced the largest SI joint motion.
Referral Patterns
- Fortin JD, Vilensky JA, Merkel GJ. Can the sacroiliac joint cause sciatica? Pain Physician. 2003 Jul;6(3):269-71. Full text. Substance P isolated intra- and peri-articularly; supports physiological explanation of sciatica-like SI joint pain as supported by previous studies (Fortin) showing ventral extravasation of injected contrast in proximity of lumbosacral plexus.