David A. Bomback, MD, spine and scoliosis surgeon at Danbury-based Connecticut Neck and Back Specialists, discusses sacroiliac joint dysfunction.
About 25 percent of patients who visit spine practices with complaints of lower back pain suffer from sacroiliac joint dysfunction, according to Dr. Bomback. With this condition, patients experience pain that emanates from the sacroiliac joint — a joint that connects the sacrum to the pelvic bone. Sacroiliac joint dysfunction occurs when the ligaments connecting these two bones become too loose or too stiff, so that that the joint becomes arthritic.
Here are three more things to know about the condition:
1. Diagnosis. "It can be difficult to diagnose," Dr. Bomback says. "All of our tests — MRIs, X-rays, bone scans 
— come back relatively unremarkable. It's a challenge."
To identify sacroiliac joint dysfunction, Dr. Bomback says he goes back to the "old days," relying on a patient's history and a physical exam to see what symptoms are consistent with the condition. This might include a patient reporting pain while rolling over, standing up or performing other activities that stress the pelvic area. For the physical exam, he attempts to reproduce the patient's symptoms by stressing the joint.
"The diagnosis is a combination of where the pain is located, what triggers are stressing that particular joint and seeing if I can reproduce the pain," he explains. "I try to differentiate the pain from other sources of discomfort, such as disc pathology, mechanical instability or arthritis."
2. Treatment. Of the sacroiliac joint dysfunction patients Dr. Bomback has worked with, he says more than 90 percent could be treated without surgery.
But if patients don't respond to these nonoperative treatments — which might include physical therapy, chiropractics, activity modification or cortisone injections — Dr. Bomback performs an additional diagnostic test, to confirm the patient is a good candidate for the sacroiliac procedure.
"I inject the area with anesthetic alone, and have the patient document their immediate pain response over the first 24 hours," he says. "If the patient notices a significant improvement in symptoms, we feel that this confirms our suspicion of sacroiliac joint dysfunction. If a patient fails conservative treatment and has responded favorably from two diagnostic injections, in my mind, then they may be deemed a surgical candidate."
3. Operation. As a last resort, a minimally invasive sacroiliac joint fusion procedure may be used to alleviate the condition. About 19,000 patients have undergone this procedure in the five to seven years it has been used, according to Dr. Bomback.
The operation, which takes around 30 minutes, may be done as an outpatient procedure or with a one-night hospital stay, depending on a patient's comorbidities. During the procedure, a surgeon places three screws across the sacroiliac joint, bridging the spine to the pelvis, in an effort to limit motion and to promote fusion of the joint.
"We address the source of the pain, which is often related to some degree of instability," Dr. Bomback says.