The clinical presentation of intervertebral disc, facet joint, nerve root, and sacroiliac (SI) joint diseases are often indistinguishable. SI joint arthritis likely accounts for a significant proportion of what is called "low-back pain" or "sciatica." Our goal was to determine the incidence of SI joint arthritis in patients with this presentation.
Computed tomographic (CT) scans of the lumbosacral spine (LSS) of patients referred with low-back pain, sciatica, spinal stenosis or disc pathology were gathered over a 3-month period. Scans were retrospectively reviewed by 2 independent readers for SI joint arthritis. When there was disagreement, the 2 readers reviewed the case and reached a concensus opinion. SI joint arthritis was considered to be present if subchondral sclerosis, osteophytosis, or cartilage loss was noted on the CT scan.
The SI joint(s) were visualized by both readers on 64 LSS CT scans performed in 29 women and 35 men, mean age 52 years. By the aforementioned criteria, 16 SI joints (25%) were considered normal by both readers. In 48 cases (75%), there was evidence of osteoarthritis. The diagnosis of osteoarthritis was made by concensus opinion in 8 of these 48 cases (16%).
There is a relatively high incidence of SI joint arthritis in patients undergoing evaluation for "low-back pain" or "sciatica." Hence, SI joint arthritis should be considered a possible diagnosis in these patients.