A Helpful Guide to Sacroiliac Joint Fusion for Pain and Dysfunction
A key symptom of sacroiliac joint (SIJ) dysfunction is pain. The sacrum (tailbone) connects to the ileum, one of the bones of the pelvis, by ligaments and tendons. Most patients report pain in one, or both, buttocks – near, or on, the posterior superior iliac spine (PSIS). However, pain radiating to the hip, posterior thigh, or even the calf has also been described.
Patients report intense pain when they have been sitting for long periods, or when they perform twisting or rotational movements. They also report:
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Pain quality: The pain is described as a dull ache, or sharp stabbing/knife-like
• Pain distribution: Buttocks, back of thigh, and upper back; can involve one or both sides
• Pain that is worse in the morning (morning stiffness) and resolves with exercise
• Limb lengths may not be equal
• Motion restriction with rotation of the hips
• Pain with touching the area over the sacrum (tailbone)
Causes of Sacroiliac Joint Dysfunction
Many patients report that their pain began spontaneously, whereas others
(around 58%) can remember a specific event, or trauma, precipitating the pain. Other contributory factors include smoking, poor physical condition, lifting, obesity, along with a family history. Pregnancy is also associated with SIJ dysfunction.
Conditions Associated with Sacroiliac Joint Pain
• Adjacent segment disease (prior spine fusion)
• Ankylosing spondylitis
• Degenerative osteoarthritis
• Degenerative sacroiliitis
• Infection and inflammation
• Leg length discrepancy
• Ligamentous laxity (pregnancy/post-pregnancy)
• Sacral disruption
• Sacroiliac Joint Disruption (post-trauma)
• Structural pelvic asymmetry
• Trauma
• Tumor
Certain bio-mechanical, muscle length or limb imbalances may also predispose a person to sacroiliac dysfunction and pain. This is likely due to altered gait patterns and repetitive stress to the SIJ, such as scoliosis, hip osteoarthritis, and poor-quality footwear.
Treatment for SIJ Dysfunction
Medications, joint injections, regenerative therapies, and physical therapy are all conservative treatments, but if those fail, or if the pain persists for many years, a surgical remedy may be indicated. A sacroiliac joint fusion will fuse the joint to reduce pain and improve stability. As a relatively new technique, it is not widely available.
Experienced surgeons, like ONZi’s Dr. Thomas Bierstedt, explain the indications as being very similar to that of a damaged lumbar spine, and that surgeons should ensure any lower back issues are addressed first.
SIJ Fusion Study Results: What the numbers tell us
A randomized and controlled clinical trial, by Polly et al., found that patients who underwent minimally invasive SIJ fusion with triangular titanium implants achieved greater pain and disability relief at 24-month follow-up than did those who underwent nonsurgical management. Six-month success rates were higher in the surgical group (81.4% vs. 26.1%). Clinically important disability index scores, at six months, showed improvement occurred in 73.3% of the SIJ fusion group vs. 13.6% of the nonsurgical management group.
Another randomized, controlled study, by Sturesson et al., found that in fusion patients (52 subjects) the mean lower back pain score had improved by 43.3 points at six months, compared with 5.7 points in the conservative treatment group. The mean disability score had improved by 26 points in the fusion patients, compared with 6 points in the conservative management group.
How is SIJ Fusion Performed?
A Sacroiliac Joint fusion is performed under general anesthesia. Thanks to both technique and technology advancements, an SI fusion can be a minimally invasive procedure, involving only one or two small incisions right above the buttock(s) below the waistline, on either side of the spine. Instead of a lateral approach, this posterior approach minimizes injury to surrounding tissue, such as muscle. A synthetic bone matrix is introduced to help strengthen the fusion, with threaded screws to fixate the bone.
The traditional side approach for SIJ Fusion (above left) interferes with muscle, while Medtronic’s Rialto system (above right) is Minimally Invasive
The medical technology company, Medtronic, has called this their Rialto fusion system. This system uses a posterior approach to the SI joint, which leads to a faster and more complete post-op recovery.
Surgery Risks
Compared to an open procedure, a minimally invasive procedure is quick and eliminates the need for a long hospital stay. Some risks are bleeding, a hematoma (a collection of blood in the tissue), an infection in the skin or deeper tissue, incomplete pain relief, injury to nerves, blood clots in the legs or lungs, and anesthetic complications. Anesthetic complications are rare and are dependent upon the overall health of the surgical patient. Most complications can be managed with medications or rarely a repeat procedure.
Recovery at Home
Postoperatively, you may be required to wear a back brace and will be encouraged to avoid repetitive bending, lifting, twisting, and athletic activities while you recover. For some time, you will also be cautioned to avoid vibrations, such as those experienced whilst driving a car.
References
Polly, D. W., Cher, D. J., Wine, K. D., Whang, P. G., Frank, C. J., Harvey, C. F., Lockstadt, H., Glaser, J. A., Limoni, R. P., Sembrano, J. N., & INSITE Study Group (2015). Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Nonsurgical Management for Sacroiliac Joint Dysfunction: 12-Month Outcomes. Neurosurgery, 77(5), 674–691. https://doi.org/10.1227/NEU.0000000000000988
Sturesson, B., Kools, D., Pflugmacher, R. et al. Six-month outcomes from a randomized controlled trial of minimally invasive SI joint fusion with triangular titanium implants vs. conservative management. Eur Spine J 26, 708–719 (2017). https://doi.org/10.1007/s00586-016-4599-9