A condition that is commonly mis-diagnosed as lumbar spine arthritis or disc disease is sacroiliac joint dysfunction, the deterioration of the two joints on the side of the lower spine that connect it to the pelvis.  Studies have found that 20 to 25% of all chronic lower back pain comes not from the spine but from the sacroliac, or SI, joint, which bears and transfers weight and movement from the upper body to the legs. When the ligaments wear out and the SI joint becomes unstable, it can generate a similar kind of sharp back pain as a ruptured disc — a sciatica-like pain down the leg.

Most spine surgeons, however, aren’t trained to look at the sacroiliac joint; they generally don’t learn about it during their residency or fellowships. And it doesn’t occur to most patients to ask. Then X-rays, MRIs and CT scans of aching, aging backs show narrowing spinal discs, without actually showing whether these discs are producing pain, further confusing the diagnosis of the suffering patient.  As a result, many people progress through the usual stages of back pain treatment, from physical therapy and chiropractic treatment to injections, laser procedures and finally to surgery, without ever addressing the true source of the pain.

One study found that among “failed” spinal fusion patients — people who had their lumbar vertebrae fused and were still in pain afterward — the SI joint was the real culprit in more than half the cases.  When a doctor knows to look at the SI joint, finding out whether it’s the source of the pain is usually pretty easy. If an injection of the local anesthetic Lidocaine into the joint produces temporary pain relief, then that’s likely where the problem resides. If so, all the treatments previously misdirected at the spine can be aimed at the proper target.

If those treatments don’t work, the next step is often surgery. Up until recently, that meant a major open fusion procedure, followed by several months of recovery.  However, a new, minimally invasive procedure is now available that uses small titanium implants to stabilize the joint. The tiny incisions mean patients recover much more quickly.