The sacrum is a triangular-shaped bone located at the base of the spine, nestled between the two hip bones. It forms the posterior part of the pelvis, connecting the spine to the lower body. This bone plays an important role in providing stability to the pelvis and upper body, and it helps to absorb forces exerted on the spine. Individuals experiencing pain often wonder if their sacrum is “out of place.”
Understanding Sacral Misalignment
The sacrum is not typically “out of place” like a dislocated joint. Instead, the term often refers to sacroiliac (SI) joint dysfunction, where the joints connecting the sacrum to the pelvis experience altered movement. These joints are strong, reinforced by strong ligaments, and designed for minimal movement, primarily to absorb impact and transfer weight.
Sacroiliac joint dysfunction can manifest as either hypomobility (too little movement or stiffness) or hypermobility (excessive movement or looseness). Both can cause pain and discomfort due to abnormal mechanics or subtle malposition. While full dislocation is rare, issues with SI joint movement are common.
Common Causes and Symptoms
Several factors can contribute to SI joint dysfunction and pain. Traumatic events such as falls directly onto the buttocks or motor vehicle accidents can injure the joints and surrounding ligaments. Repetitive stress from activities that place uneven pressure on the pelvis, poor posture, or even a subtle difference in leg length can also contribute to the problem.
Pregnancy is a common cause, as hormonal changes cause ligaments to loosen in preparation for childbirth, potentially leading to increased joint laxity. Inflammatory conditions like osteoarthritis and ankylosing spondylitis can cause inflammation within the SI joints, known as sacroiliitis. Degenerative changes can also lead to pain.
Symptoms of SI joint dysfunction include pain in the lower back and buttock area, often on one side. This pain can be a dull ache or a sharp, stabbing sensation and may radiate down the leg, sometimes mimicking sciatica. Individuals might experience stiffness in the hips and lower back, especially in the morning or after prolonged sitting or standing. Pain often worsens with specific movements such as climbing stairs, running, standing on one leg, or transitioning from sitting to standing.
How Sacral Issues Are Diagnosed
Diagnosing SI joint dysfunction can be challenging because its symptoms often resemble those of other lower back or hip conditions. A healthcare professional begins with a detailed review of a patient’s medical history, discussing the nature, location, and aggravating factors of the pain. This is followed by a thorough physical examination, which includes observing posture and movement patterns.
During the physical exam, specific provocative tests are performed to reproduce pain by stressing the SI joint. These include:
- FABER (Flexion, Abduction, External Rotation) test
- Gaenslen’s test
- Compression tests
- Distraction tests
A diagnosis is often supported when at least three of these tests elicit the patient’s familiar pain.
Imaging studies like X-rays, MRI, or CT scans are sometimes used, primarily to rule out other conditions such as disc herniation or arthritis in other parts of the spine. However, imaging alone cannot definitively diagnose SI joint dysfunction, as pain responses cannot be visualized, and some abnormal findings on scans may not be the source of pain. A highly accurate diagnostic method involves injecting a numbing medication directly into the SI joint under image guidance. Significant pain relief confirms the SI joint as the pain source.
Effective Treatment and Management
Treatment for SI joint pain and dysfunction begins with conservative approaches aimed at reducing pain and restoring normal joint function. Initial management may involve rest, applying ice to reduce inflammation, and heat to improve blood flow. Over-the-counter anti-inflammatory medications, such as ibuprofen or naproxen, can help manage pain and swelling. Muscle relaxers may be prescribed for acute pain.
Physical therapy is a common and effective treatment, focusing on exercises to strengthen core and pelvic muscles, improve posture, and restore joint mobility. A physical therapist may also use manual therapy techniques, such as soft tissue release or joint mobilization, to improve flexibility and alignment. For individuals with hypermobility, a pelvic support belt can provide external stability to the joint.
If conservative measures do not provide sufficient relief, other options exist. Corticosteroid injections, delivered directly into the SI joint, can reduce inflammation and pain for an extended period. Radiofrequency ablation, which uses heat to interrupt pain signals, may be considered for longer-lasting relief. In rare instances, when severe instability or pain persists, minimally invasive SI joint fusion surgery may be an option to stabilize the joint.