The sacroiliac (SI) joint, located at the base of the spine, connects the sacrum and pelvis. It transfers forces between the upper and lower body and acts as a shock absorber, managing loads from activities. When this joint causes persistent discomfort, SI joint fusion surgery may be considered.
Understanding Sacroiliac Joint Dysfunction
Sacroiliac joint dysfunction occurs when the joint’s normal motion is altered, either with too much movement (hypermobility) or too little (hypomobility). This can cause pain in the lower back, buttock, or hip, sometimes radiating down the leg similar to sciatica. Patients may also experience numbness, tingling, weakness in the leg, or difficulty with sitting, standing, or walking.
Various factors can contribute to SI joint dysfunction, including trauma, arthritic conditions, and degenerative changes. Pregnancy can also cause ligament laxity due to hormonal changes, leading to hypermobility and pain. Prior lumbar spine surgeries can sometimes shift stress to the SI joint. Diagnosing SI joint dysfunction is challenging due to its symptoms mimicking other back conditions, but it typically involves a physical examination and diagnostic injections to confirm the SI joint as the pain source.
The Surgical Procedure
SI joint fusion surgery stabilizes the joint and alleviates chronic pain by joining the sacrum and ilium bones into a single, solid structure. The procedure is typically performed under general anesthesia using minimally invasive techniques. Small incisions, usually made on the side of the buttock, reduce disruption to surrounding muscles and tissues, leading to quicker recovery times.
During surgery, the surgeon accesses the ilium. A small hole is created through the ilium for specialized instruments and implants. The SI joint surfaces are then prepared, which may involve clearing cartilage or creating space to encourage bone growth.
Implants are inserted across the joint to hold the bones in place and promote fusion. Bone graft material may also be used to enhance the fusion process. Fluoroscopic imaging guides the precise placement of instruments and implants.
Recovery and Post-Operative Care
Following SI joint fusion surgery, patients have a recovery period focused on healing and regaining mobility. Most patients are discharged the same day or after an overnight stay. Initial pain management involves prescribed medications, and ice and heat therapy can reduce inflammation and muscle tension.
Activity restrictions are important in the early weeks to protect the healing joint. Patients limit weight-bearing on the operated side, often using assistive devices like a cane or crutches for several weeks. Avoiding heavy lifting, bending, and twisting is crucial. Physical therapy plays a significant role in rehabilitation, progressing from gentle exercises to active stretching and strengthening to restore function. While some pain relief is felt within weeks, complete bone fusion can take up to six months, with a gradual return to normal activities.
Who Is a Candidate and Alternatives
SI joint fusion surgery is considered for individuals with chronic lower back pain attributed to SI joint dysfunction. Candidacy is determined after conservative, non-surgical treatments fail to provide lasting relief. Symptoms must be confirmed as originating from the SI joint, often through diagnostic injections. Imaging studies like X-rays, CT scans, or MRIs may also assess structural changes.
Before surgery, non-surgical alternatives are attempted to manage SI joint pain. These include physical therapy to strengthen surrounding muscles, pain medications like NSAIDs, and injections such as corticosteroids or nerve blocks. Other approaches involve chiropractic care or a sacral belt or brace for external support. A specialist determines the most appropriate treatment based on the individual’s condition and response to conservative therapies.