Posterior Sacroiliac Fusion Procedures

At the base of the spine are the sacroiliac joints, which join the spine to the hips. Although these joints provide only two or three degrees of flexibility, they are important in bodily motion, especially walking. Like any other joint, however, they can produce pain if they become damaged or diseased.

The Posterior Sacroiliac Fusion System or PSIF was developed to treat pain caused by instability in the sacroiliac joints. This technique uses a bone graft to fuse the joint, making it immobile. Up to 85 percent of patients who underwent the procedure experienced an improvement in pain symptoms and almost 75 percent had improved mobility.

The Sacroiliac Joint

There are two sacroiliac joints at the bottom of the spine; one on either side of the sacrum which is the lowest bone of the spine. Although there is very little flexibility in these joints—just a few degrees—these joints serve an important purpose. By joining the base of the spine to the hips, the weight of the axial skeleton can be transferred to the pelvis. In turn, this weight is then distributed to the two femur bones while standing or the ischial bones while sitting.

Due to the high stresses placed on the sacroiliac joints, there are several very strong ligaments found in the joint, including

  • Anterior sacroiliac ligament
  • Posterior sacroiliac ligament
  • Sacrotuberous ligament
  • Sacrospinous ligament

Sacroiliac Joint Pain

If you are experiencing sharp, stabbing, or dull pain in the hips or lower back, you may be suffering from sacroiliac joint pain. This pain is likely to worsen if you stand up, walk up stairs or bend and twist at the waist.

Among the most common causes of sacroiliac joint pain are

  • Repeated pounding pressure as from jogging
  • Injury or trauma
  • Prior spine surgery
  • Pregnancy
  • Uneven leg length
  • Arthritis

It can be difficult to diagnose sacroiliac joint pain because there are many back pain conditions that can refer pain to this area of the body including sciatica, osteoarthritis, or bursitis of the hip.  Furthermore, scanning this joint with x-ray, CT scan or MRI may not pick up any joint issues.

The most definitive test for sacroiliac joint pain is injecting a numbing agent into the joint and witnessing a significant reduction in pain severity.

Traditional Treatments for Sacroiliac Joint Pain

In the past, doctors have recommended a variety of therapies for sacroiliac joint pain, including

  • Pain medication—if the pain is manageable, then your doctor may only recommend that you take pain medications; initially, you may only need over-the-counter medications like Tylenol or aspirin, but if the pain symptoms persist or worsen, your doctor may prescribe more powerful drugs.
  • Rest—in many cases, sacroiliac joint pain can be remedied merely by resting. No more than two days of rest is recommended as more than that may cause stiffness and deconditioning.
  • Corticosteroid injection—your physician may inject an anesthetic along with a corticosteroid to reduce the pain and swelling in the sacroiliac joint.
  • Physical therapy—along with a series of exercises designed to strengthen and stretch the muscles and ligaments around the sacroiliac joint, a physical therapist may use massage, hot and cold and manual manipulation to reduce pain.
  • Joint treatment—if the underlying cause of the sacroiliac joint pain is related to another health condition like arthritis or cancer, then it is necessary to first manage this condition.
  • Support brace—if the issue is that the joint is too loose, then a pelvic brace may be used to stabilize the joint.

The good news is that most patients with sacroiliac joint pain respond well to more conservative therapies although it may require an extended period of treatment.

Posterior Sacroiliac Fusion System

If the sacroiliac joint has become unstable, which in turn is producing pain, then your physician may recommend that the joint be fused, during a fusion procedure, a bone graft or other device is implanted across the joint. This serves as the scaffolding over which new bone grows, eventually immobilizing the joint and stabilizing it.

Traditional sacroiliac joint surgery requires a large incision that allows access to the SI joint. The surgeon may remove cartilage or bone in the joint causing the pain and dysfunction or install a bone graft to stabilize the joint. This kind of procedure normally requires a hospital stay of several days as well as an extended recovery period. This kind of procedure is rarely performed these days because of the longer recovery period and greater risk of complications.

The Posterior Sacroiliac Fusion System is a minimally invasive technique that requires only a small incision in the buttock. The PSIF procedure typically takes only an hour to complete, allowing patients to return home much sooner than with traditional open surgery.

The procedure begins with the patient lying face down and under MAC or general anesthesia. The surgeon will make a 2-to-3-centimeter incision in the side of the buttock. A small almond sized allograft is placed in between the ilium and sacrum.  The allograft is used to help keep the ilium and sacrum from moving which helps control the pain.

After cleaning the incision site, it is closed with a few simple sutures.

The recovery period following a Posterior Sacroiliac Fusion procedure is fast and patients walk out the same day of surgery.  Patients usually notice pain relief as soon as a few days or up to a few weeks following the procedure. 

Physical therapy should also be performed in a gradual, highly controlled manner. This should help strengthen and stretch musculature in the lower back, hips, and legs, which helps maintain joint functions in those areas.

Article written by: Dr. Robert Moghim – CEO/Founder Colorado Pain Care

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