The sacroiliac (SI) joint is a frequent source of lower back discomfort, and its dysfunction can mimic other common spine and hip problems. Pinpointing the exact cause of pain in this complex region is challenging, often requiring specialized knowledge and systematic evaluation. For individuals struggling with persistent lower back pain that may originate from the SI joint, consulting a specialist is the path toward a precise diagnosis and effective treatment plan.
Understanding Sacroiliac Joint Pain
The sacroiliac joints are situated on either side of the spine, connecting the sacrum—the triangular bone at the base of the spine—to the ilium, which is the largest bone of the pelvis. These paired joints are designed to transfer weight and absorb shock between the upper body and the lower extremities, exhibiting only minimal motion. When either joint is subject to inflammation, excessive movement (hypermobility), or restricted movement (hypomobility), it can result in sacroiliac joint dysfunction.
The pain associated with SI joint issues is typically felt in the lower back and buttocks, but it can radiate into the groin, hip, or down the leg, sometimes mimicking sciatica. Activities that stress the joint often worsen the symptoms, such as prolonged standing, climbing stairs, or shifting weight to one leg. Common causes of this dysfunction include degenerative arthritis, trauma from a fall or accident, and biomechanical changes related to pregnancy or previous lumbar spine surgery.
The Orthopedic Specialist’s Role in Diagnosis
Orthopedic doctors, particularly those specializing in the spine and pelvis, routinely evaluate and manage SI joint pain. Since SI joint pain overlaps significantly with conditions like herniated discs or hip arthritis, the specialist’s role begins with a meticulous differential diagnosis. This process involves a comprehensive medical history review and a targeted physical examination to rule out other possible pain generators.
During the physical exam, the orthopedic doctor employs specific provocative maneuvers designed to stress the SI joint and reproduce the patient’s pain. These tests, such as the Thigh Thrust or the Distraction test, help the physician determine if the joint is the likely source of discomfort. Imaging studies like X-rays, CT scans, or MRIs are often used to exclude other pathologies, though they may not always reveal the underlying SI joint dysfunction.
The confirmation of SI joint dysfunction relies on a diagnostic injection, which is considered the most reliable method. Under fluoroscopic guidance (real-time X-ray), the specialist injects a local anesthetic directly into the joint space. If the patient experiences a substantial, temporary reduction in pain—typically 50% to 75% relief—the diagnosis of SI joint pain is confirmed.
Conservative Treatment Modalities
Following a confirmed diagnosis, the initial approach to SI joint pain management is non-surgical, focusing on conservative treatment modalities. Treatment typically involves a combination of medication and targeted physical therapy. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often prescribed to reduce inflammation and pain, and sometimes muscle relaxants are used to address related muscle spasms.
Physical therapy is a first-line treatment, aiming to restore proper function and stability to the pelvis and surrounding structures. Therapists focus on exercises that strengthen the core and pelvic floor muscles, which are important for stabilizing the SI joint. They may also use manual therapy techniques to improve joint mobility or recommend a sacroiliac belt to provide external support for hypermobile joints.
When pain persists despite physical therapy and oral medications, therapeutic injections are often introduced. A therapeutic injection combines an anesthetic with a corticosteroid to deliver powerful anti-inflammatory medication directly into the joint space, aiming for longer-term relief than a diagnostic block. For more chronic pain, radiofrequency ablation (RFA) can be considered, which uses heat to interrupt pain signals from the sensory nerves around the joint, potentially offering pain relief for several months.
Surgical and Advanced Interventions
Surgery is generally reserved for patients whose severe SI joint pain has not responded to a prolonged course of conservative management, including therapeutic injections. The primary surgical procedure performed by orthopedic specialists is minimally invasive SI joint fusion. This procedure is designed to stabilize the joint by permanently fusing the sacrum and the ilium.
During the minimally invasive fusion procedure, the orthopedic surgeon uses small incisions to insert titanium implants across the joint. These implants, often triangular in shape, are guided into place using fluoroscopy or 3D navigation to ensure accurate positioning and minimal disruption to surrounding soft tissues.
The decision to proceed with fusion often involves an interdisciplinary team, including the orthopedic surgeon, pain management specialists, and rheumatologists, especially if inflammatory conditions are suspected. While complete pain relief is rare, patients typically experience a significant decrease in pain and an improvement in daily function following the procedure.