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Understanding Sacroiliac Dysfunction and Piriformis Syndrome

Sacroiliac dysfunction is a common cause of back pain. In most instances, the condition and the discomfort that comes with it can be managed through conservative treatment; however, some cases may require spine surgery.

The sacroiliac joint is located in the low back between the spine and hip joint, and normally does not move much. Misalignment of this joint can cause the pain associated with sacroiliac dysfunction.

Sacroiliac joint pain is usually located in the low back, just to the side of the midline. It is usually one sided, but not always. The pain often radiates down to the knee and into the groin on the same side. Typically, it is difficult to find a comfortable position when lying in bed. Sacroiliac joint pain can become severe and disabling if not treated.

The typical patient is often a woman in her 30s or 40s who has had children. It is thought that the relaxation of the sacroiliac ligaments necessary for childbirth does not fully reverse, and that a subsequent minor trauma may sublux (partially dislocate) the joint and cause pain. Younger women may develop sacroiliac problems as a result of sport or other injuries. The condition also occurs in men, but less frequently and usually from more severe injuries, often involving lifting while the trunk is in torsion.

Accurately diagnosing sacroiliac joint dysfunction can be difficult, and must be done by clinical exam. Its symptoms can mimic those of other common conditions, such as disc herniation and radiculopathy (pain along the sciatic nerve that radiates down the leg). Unless a doctor specifically checks for sacroiliac dysfunction, the physical examination often will turn out "normal" and some patients may be told that nothing is wrong with them.

During the exam, the doctor may try to determine if the sacroiliac joint is the cause of pain by moving the joint. If the movement recreates the patient's pain, and no other cause of pain has been found (such as a disc herniation on an MRI scan), the sacroiliac joint may be the cause of the pain.

A sacroiliac joint injection is another diagnostic tool that may be used. In this test, a physician uses fluoroscopic guidance (live X-ray) and inserts a needle into the sacroiliac joint to inject lidocaine (a numbing solution). If the injection relieves the patient's pain, it can be inferred that the sacroiliac joint is the source of the pain. A steroid solution also may be injected to decrease inflammation in the sacroiliac joint and decrease pain.

About 40% of the time, sacroiliac dysfunction is associated with piriformis syndrome. The piriformis is a small muscle in the buttock that stabilizes the sacroiliac joint. When irritated, it causes pain in the buttock. The piriformis muscle happens to overlap the sciatic nerve and can also cause sciatic pain down the leg all the way to the foot. This is often mistaken for sciatica, caused by a pinched nerve root in the spine.

If diagnosed early, the majority of patients with sacroiliac dysfunction and/or piriformis syndrome will improve with conservative treatment, which may include manipulation, physical therapy and anesthetic/steroid injections. More recently, BOTOX® injections have been used to relax the piriformis muscle.

For those who do not respond to conservative measures, minimally-invasive surgery is the appropriate next step, which involves stabilizing the sacroiliac joint through fixation and fusion. Sometimes the piriformis muscle also may need to be treated surgically to relieve pressure on the sciatic nerve.

Dr. Michael A. Amaral, FACS, is a partner in Spine and Sacroiliac Specialists, LLC, in Atlanta, Georgia. A native of Paris, France, Dr. Amaral holds a Doctor of Medicine degree from the (Free) University of Brussels School of Medicine and a BA degree from Boston University. After completing his residency at the University of Chicago, Dr. Amaral served as an instructor of neurosurgery at the University of Minnesota and as an adjunct assistant professor of surgery at the Chicago College of Osteopathic Medicine, Midwestern University.

Here, Dr. Amaral answers some questions he frequently fields from patients facing sacroiliac and/or piriformis surgery.

What Does Sacroiliac Surgery Involve?
Prior to surgery, the physical therapy team will align the sacroiliac joints and pelvic girdle, both before and after anesthesia. This is, in our opinion, a critical step for proper healing. Because the position is face down and because sacroiliac surgery is significant and requires a relaxed patient to make sure nothing moves until the joints are fixated, general anesthesia with a tube in the trachea is necessary.

In some instances, surgery will involve placing screws in only one side of the joint, a relatively "simple" procedure. Two titanium bone screws are inserted into the joint, using X-rays and guiding pins, through tiny incisions (about ¼ inch) in the skin. Nerves and nerve roots are electrically monitored during the surgery to minimize injury or irritation. The procedure generally takes 30 to 45 minutes, and patients usually may go home that day.

In most cases, however, there is significant asymmetry in the sacroiliac joint and screws must be inserted in both sides to further stabilize the pelvic girdle. The painful side is fused using either the patient's own bone (harvested at the surgical site), artificial bone or a new alternative called bone morphogenetic protein (BMP). This procedure typically lasts two to three hours and requires an extra incision (usually 2-1/2 to 3 inches long) for the fusion. Hospitalization usually lasts two to three days.

What Does Piriformis Surgery Involve?
In piriformis surgery, the surgeon will cut the tendon of the piriformis muscle at its point of insertion at the hip joint, therefore relaxing it. This requires an incision about 2-1/2 to 3 inches long. This procedure usually adds another 45 minutes to the sacroiliac surgery.

How Are The Incisions Closed?
The incision is usually closed with skin glue which, usually, leaves better looking wounds. Deep dissolvable stitches are also used. After the surgery, the wounds should be cleaned with soap and water only (and nothing else). They can be left open to air if there is no drainage. Showers are okay. Patients should avoid the bathtub for a couple of weeks, until the wounds are fully healed.

Are There Any Potential Complications?
Complications are a potential risk of any type of surgical procedure. Some possible complications from sacroiliac and/or piriformis surgery may include:

  • Blood clot or infection at the surgical site
  • Deep vein blood clots (deep vein thrombosis) that can migrate to the lungs (pulmonary embolism)
  • Misalignment of the sacroiliac join
  • Nerve or nerve root irritation
  • Muscle spasm
  • Fixation device (screw) failure
  • Pressure sores

However, the likelihood that any of these complications will occur is no greater for sacroiliac and/or piriformis surgery than for other surgeries involving fixation and bone fusion. Please discuss any concerns you may have with your surgeon.

What Should I Do To Prepare For Spine Surgery?
The following medications, herbs and vitamins should be discontinued at least two weeks prior to surgery as they may cause excessive bleeding during surgery.

  • Blood thinners
  • Aspirin
  • Vitamin E
  • Garlic
  • Ginseng
  • Gingko Biloba
  • Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), i.e., ibuprofen, naproxen, etc.

NSAIDS also can interfere with bone fusion. If your surgery includes bone fusion, avoid these drugs for two weeks before surgery and at least six months after surgery.

In some studies, alendronate (a drug for osteoporosis) has also been shown to interfere with bone fusion. Please consult with your physician about alternatives.

Stop smoking, both before and after surgery. Smoking severely interferes with bone fusion and causes difficulties with anesthesia. It is very important that you do this.

The evening before your surgery, take an enema or laxative (available over-the counter). At bedtime, take an acid reducer (also available over-the-counter) to prevent stress ulcers of the stomach.

Do not eat nor drink anything after midnight the evening before surgery unless your physician tells you to take your medications with a small sip of water
Please consult with your physician for any further pre-operative instructions.

Why Is An Enema or Laxative Necessary The Evening Before Surgery?
The surgery requires many X-rays to visualize placement of the screws. Food in the bowels obscures the bone landmarks.

Why Is A Pregnancy Test Necessary Before Surgery?
The test is only necessary if you are in an age group when pregnancy is possible and if you didn't have any surgery that would prevent it (such as a hysterectomy). The amount of X-rays needed for the procedure is detrimental to a fetus.

Will I Be Able To Take Any Pain Medications?
You will most likely be hooked up to an intravenous pain pump while you're in the hospital. This may be in conjunction with other medications. At discharge, your physician will prescribe the appropriate pain medication for you.

When Can I Get Up?
We encourage you to get up as soon as possible. Many patients require a walker and a bedside commode for comfort. You will most likely also need these items at home for two to three months.

How Soon Will I Be Able To Go Back To Work?
This depends on your line of work and on how you are doing after the surgery. One to three months is the average. Someone who performs sedentary, clerical type work will most likely be able to return to work sooner than someone whose job involves heavy lifting, twisting and squatting.

Will I Need Physical Therapy?
We usually start physical therapy about three weeks after surgery. Your surgeon will determine the appropriate protocol for you.

What Activities Will I Be Able To Do?
You must avoid any activity that could cause more injury, and increase your activity level slowly and in steps, which varies with each individual patient. Moderate walking and other activities are okay as long as they do not cause pain. Swimming is good for the back. Avoid bicycling. This can flare up pain in the surgical area. Walking against resistance (when in water, for example) is also to be avoided. Talk to your surgeon and physical therapist about any particular concerns.

Will My Sacroiliac Screws Set Off The Alarm At The Airport?
No—the screws are made of titanium and are not magnetic. They will not send off the alarm.

What About Pregnancy After Sacroiliac/Piriformis Surgery?
Pregnancy is possible after this type of surgery; however, it is recommended that you not get pregnant within a year of the surgery, so please use appropriate birth control measures. Some women have had a normal delivery after surgery but there are significant chances that a C-section might be necessary. Make sure you notify your obstetrician that you had this procedure done.

Why Can't I Smoke?
Smoking is not good when undergoing general endotracheal anesthesia. It also specifically interferes with bone fusion. The nicotine causes spasm of the small blood vessels that supply blood to the bone graft. Bone fusion requires a lot of blood. The chance of a successful bone fusion drops dramatically. Why go through so much surgery if you're not going to be able to do what is necessary to maximize the chance of success?

BOTOX® is a registered trademark of Allergan, Inc.

The materials on this Web site are for your general educational information only. Information you read on this Web site cannot replace the relationship that you have with your health care professional. We do not practice medicine or provide medical services or advice as a part of this Web site. You should always talk to your health care professional for diagnosis and treatment.

  • Published: July 12, 2006
  • Updated: March 18, 2008