Sacroiliitis: The Great Imposter

Comp Clues
Sitting on a toilet is a relaxing experience, usually. It wasn’t for the first sacroiliac injury I ever treated. She was a rotund young lady in her mid-twenties. While sitting on a commode in a luxury hotel, it came unbolted from the wall whereupon she and the bowl landed on the floor. She sustained a left sacroiliac strain from this, which unfortunately led to chronic sacroiliac pain, sacroiliitis. She subsequently had a significant (perhaps excessive) course of evaluation, treatment, disability claims and litigation. I distinctly recall feeling sorry for that hotel chain, let alone myself and the other physicians from whom she sought care.

Imposter? Better said, the differential diagnosis of medical problems or injuries than can cause similar signs and symptoms is extensive. This is because the locations of pain and radiation can differ among patients, and vary for a single patient. Inflammatory and seronegative arthropathies, lumbar radiculitis, degenerative disc disease, spondylosis, spondylolysis, sacral fracture, metastatic disease, pelvic pain, (e.g., uterine fibroids), can all have similar presenting symptoms. It can accompany mechanical imbalance, such as that seen with leg length discrepancies, scoliosis, spasticity, etc. Because symptoms are obscure and diagnosis challenging, expensive testing is usually non-diagnostic and ill-defined treatment often unsuccessful. Patients often have had extensive evaluations, MRI’s, EMG’s, etc, without clarification of the problem.

Sacroiliac strain/dysfunction should be in the mind of the examiner for any patient with sciatica, i.e. lumbar pain and leg pain. One of my favorite teachers in medical school, someone very good at physical examination, told us one day, “you can see the same things I see, if you look for them.” If not considered, the diagnosis will be missed. There will usually be a historical event, perhaps repetitive, of differential rotational force across the pelvis. Pertinent negatives should exclude other, non-occupational, medical conditions that can imitate the same symptoms. I’ve listed some of those conditions I’ve seen in practice, above. On exam, specific tenderness over the sacroiliac joint it usually (not always) present, and Patrick and Gaenslen exam maneuvers can be supportive in the empiric diagnosis. Neurological, musculoskeletal, abdominal examinations should be negative. A fluoroscopically guided diagnostic injection of the sacroiliac joint provides the best diagnostic confirmation.

Special testing should include, lumbar X-rays to include oblique and flexion/extension views, lumbar MRI, and rheumatologic laboratories. These are to exclude vertebral compression fracture, spondylolisthesis, spondylosis, disc pathology, instability, and rheumatologic conditions. If complete pain relief is noted after an injection (a diagnostic response) is seen, but with rapid return of significant pain the same or next day, a bone scan or pelvic MR should be considered to exclude a pelvic/sacral fracture or other destructive pathology, if warranted by history or laboratory abnormalities.

Fluoroscopically guided sacroiliac injections provide diagnostic and potentially therapeutic benefit. With direct visualization, the joint can be anesthetized by injection, plus corticosteroid can be delivered simultaneously. Complete or near complete resolution of pain immediately, is considered diagnostic. Fluoroscopy is the only reliable way to inject the joint, as it provides real time confirmation of needle location by direct visualization. The sacroiliac joint can only be entered in the inferior third of the visualized joint on X-ray due to the many ligamentous attachments (see figure). This is very difficult to palpate except in the very thin. While blind injections can sometimes be effective, a recent study using post injection CT, suggests an 80% likelihood of missing the joint by blind injection. This is clearly unacceptable in the management of personal or occupational injuries.

Treatment should include non-opiate analgesics, physical therapies for pelvic stabilization (preferably with a therapist having an interest in this type of injury), and sacroiliac supports can be useful for some patients. Work restrictions should limit bending at the waist, squatting, and climbing. Naturally, this is amended based on clinical progress and the patient’s occupation. A functional capacity evaluation may be necessary if there are concerns as to whether the patient is able to match his/her job description. Maximal medical improvement can be reached in four to six weeks, if not sooner, in my experience. If there are persisting symptoms, a small permanent partial impairment rating of one to three percent is not unreasonable.

While in college, I strained my right sacroiliac joint running up a staircase, skipping steps with each stride. It was extremely painful. I could barely walk on it for several days. Thankfully, it resolved with self-treatment and exercise. I wish I could say this is always the case. My experience is that the natural history of the injury is highly variable and essentially patient specific. Some people get over it, some get better, and some don’t.

Sacroiliitis is in part a diagnosis of exclusion. If suggested by history, exam, and in the absence of an obvious source for the patient’s symptoms otherwise, a diagnostic sacroiliac injection should be considered. If the diagnosis is confirmed, reasonable treatment can be completed expeditiously. If the injection is non-diagnostic, it’s on to the next item on your differential. Arriving at the correct diagnosis is the first step to successful treatment.

I cannot forget the first patient I treated with post-traumatic sacroiliitis. Nor can I forget my own experience with sacroiliac pain. One thing is sure. Whenever I go to a public restroom, I first look to make sure the commode is securely fastened to the floor.

Dr. Bergeron is board certified in Physical Medicine and Rehabilitation and Pain Medicine. He has recently relocated from Terre Haute to Indianapolis.

New Location:

Joseph W. Bergeron, M.D.
9292 N. Meridian St., suite 111
Indianapolis, IN 46260
Phone (317) 705-0909
Fax (317) 705-0910