The sacroiliac (SI) joints are located in the lower back, connecting the sacrum (the triangular bone at the base of the spine) to the ilium (the large bones of the pelvis). These two joints act as shock absorbers, transferring weight and forces between the upper body and the legs, while also providing stability to the pelvis. When these joints become dysfunctional or inflamed, they can cause pain that can significantly impact daily activities. For some individuals, when conservative treatments do not provide sufficient relief, sacroiliac joint surgery may be considered as a treatment option.
When is SI Joint Surgery Considered?
Sacroiliac joint surgery is considered after a diagnostic process confirms the SI joint as the source of pain and when conservative treatments have not provided adequate relief. Diagnosing SI joint pain can be challenging because its symptoms often mimic other lower back conditions, such as pain in the lower back, buttocks, hip, or groin. A physician will conduct a physical examination, including specific movements to provoke symptoms, and review the patient’s medical history.
Diagnostic injections are a key step in confirming the SI joint as the pain generator. During this procedure, a numbing medication, and sometimes a steroid, is injected directly into the SI joint, often guided by X-ray (fluoroscopy) for precise placement. If the patient experiences significant, albeit temporary, pain relief, it indicates that the SI joint is the source of pain. This diagnostic confirmation is important before considering surgical intervention.
Surgery is reserved for individuals whose pain is debilitating and persistent, even after several months of non-surgical approaches. These conservative treatments include physical therapy, oral medications, and therapeutic injections. This ensures less invasive options are fully explored before a surgical solution.
Types of SI Joint Surgery
Sacroiliac joint surgery aims to stabilize the joint, often through fusion, where the sacrum and ilium bones are encouraged to grow together. There are two main categories of SI joint fusion surgery: open surgery and minimally invasive surgery (MIS). Historically, open SI joint fusion involved a larger incision to directly access the joint. This approach required more extensive tissue dissection, removal of cartilage, and the use of bone grafts and screws to promote fusion.
Minimally invasive SI joint fusion has become the more common approach due to several advantages. This technique involves one or more smaller incisions, typically less than 2-4 centimeters, in the side of the buttock. Through these smaller openings, specialized instruments prepare the joint surfaces and insert implants, such as titanium rods or screws, across the SI joint. These implants stabilize the joint immediately and create a framework for bone to grow across the joint, leading to fusion over time.
What Happens During SI Joint Surgery?
The process of SI joint surgery begins with pre-operative preparations. Patients are placed under general anesthesia. The patient is positioned face down on the operating table to allow the surgical team access to the SI joint area. The surgical site, the side of the buttock, is then sterilized to minimize the risk of infection.
For a minimally invasive fusion, a small incision, typically 2 to 3 centimeters in length, is made over the targeted area. The surgeon navigates through the gluteal muscles to reach the ilium bone. A guide pin is then inserted, followed by specialized tools to create a pathway through the ilium, providing access to the sacrum. Real-time X-ray imaging, known as fluoroscopy, guides the placement of instruments and ensures accuracy.
Once the pathway is established, the joint surfaces are prepared by removing some cartilage to encourage bone growth across the joint. Implants, made of titanium alloy, are then introduced through the created channel and positioned across the SI joint to provide immediate stability. Bone graft material can also be packed into the joint space to further promote fusion. After the implants are securely in place and confirmed by imaging, the incision is closed with sutures. The entire procedure usually lasts about an hour.
Life After SI Joint Surgery
Following SI joint surgery, immediate post-operative care focuses on pain management and ensuring patient comfort. Patients awaken in a recovery area where vital signs are monitored, and pain medication is administered as needed. Patients can return home the same day or after a short hospital stay, usually one to three days, depending on the surgical approach and individual recovery progress. For about 3-4 weeks, patients may need to use assistive devices like crutches or a walker, as full weight-bearing on the operated leg is restricted.
A structured rehabilitation program, including physical therapy, is an important part of the recovery process. Physical therapy begins with gentle, passive range of motion exercises to reduce stiffness and improve flexibility in the hip and pelvis. As healing progresses, exercises will advance to include strengthening for the core, lower back, and legs, alongside activities to improve balance and proper body mechanics. Adherence to post-operative instructions, such as avoiding heavy lifting, twisting, or excessive bending, is important to allow the bones to fuse properly. While significant pain relief is experienced within weeks or months, the complete bone fusion process can take up to six months or longer.