The SI joint functions to transfer force and energy from the spine to the pelvis. Proper functioning of the SI joint requires for these two bony structures (sacrum and ilium) to be both stable and flexible, relying on balanced muscular and ligamentous attachments. Imbalances between the two can result in increased or asymmetric stress through the joint leading to pathological motion and pain. When symptoms persist for several weeks or months and do not respond to nonsurgical treatment, sacroiliac joint fusion may be recommended. The most common method of sacroiliac joint fusion is a minimally-invasive procedure, performed through a small incision in the buttock. Open sacroiliac joint fusion is rarely used due to extensive healing processes and higher complication rates. An example of this procedure is LinQ Sacroiliac Joint Fusion by PainTEQ.