SI joint infections are extremely rare, but published studies suggest that over 50 percent of the reported cases were not correctly diagnosed for more than 10 days after symptoms were first reported by the patients experiencing them.¹

Because the symptoms of sacroiliac joint infection are much like those of sciatica or a ruptured disc, for example, they can be mistakenly attributed to and treated as those conditions first. But there are distinct characteristics that spine experts look for when patients present with symptoms including fever, low back pain, buttock pain on one or both sides, deep thigh pain with difficulty walking, or problems with stair climbing.²

In about half of the cases where infection is the cause of SI joint dysfunction, preexisting bacteria in the body can be identified as causing the bacterial spread of infection to the SI joint.² There is quite a bit of vascular tissue in the area of the body where the SI joint resides, making it a rich environment in which bacteria can multiply. Of importance here is that SI joint infection can happen to anyone, but the majority of cases are usually seen in children and young adults. The most commonly reported bacterial organism to cause these types of infections is called Staphylococcus aureus, or more commonly referred to as a “staph infection.”

Diagnosing a sacroiliac infection early is of paramount concern and is usually accomplished by a complete medical history and evaluation, specific diagnostic maneuvers performed by the physician, blood tests to determine infection, and in some cases MRI of the pelvis.

Upon making the diagnosis of an SI joint infection, patients are usually admitted to the hospital to undergo a biopsy and culture of the bacteria. Once the offending bacteria is identified, physicians know which type of antibiotic therapy will work best to eliminate it. In the first day or two of diagnosis, physicians will monitor closely the body’s response to the medications given to fight the infection. If an appropriate positive response is not seen within 48-hours, drainage of the spinal fluid containing the bacteria will usually result in appropriate resolution of the infection. In most cases, especially those which are identified early on in the SI infection timeline, patients recover completely and respond well to the prescribed medications within four to eight weeks.

Though SI joint infections are rare, they require immediate and focused attention when they are diagnosed so that they do not lead to larger problems down the road. In some cases where an infection wasn’t identified early on, more lasting damage to the SI joint can occur, resulting in SI joint dysfunction. For this reason, it is important to be treated by a specialist physician experienced in diagnosing and treating SI joint infection as soon as it is suspected. To find a provider in your area, visit our Find a Doctor page.