SI Joint Pain: Why the Back of Your Hip May Hurt

Lower back pain does not always come from the spine itself. Sometimes, pain that feels like low back pain, hip pain, buttock pain, or pain near the pelvis may be coming from the sacroiliac joint. This joint is often called the SI joint, and it can be an overlooked source of pain for many patients.

The sacroiliac joints sit where the lower spine meets the pelvis. There is one SI joint on each side of the body, connecting the sacrum to the iliac bones of the pelvis. These joints do not move as much as the shoulder or knee, but they play an important role in transferring weight and force between the upper body and legs. When the SI joint becomes irritated, inflamed, unstable, or overloaded, it can cause pain that affects walking, sitting, standing, bending, and exercise.

SI joint pain can be difficult to recognize because it often overlaps with other conditions. Patients may feel pain on one side of the lower back, deep in the buttock, along the back of the hip, or sometimes into the thigh. It may feel worse when climbing stairs, standing from a seated position, rolling over in bed, standing on one leg, or sitting for long periods. Some patients describe the pain as sharp and catching, while others feel a deep ache or pressure.

Because the symptoms can mimic lumbar disc pain, facet joint pain, hip problems, or muscle strain, diagnosis requires a careful exam. At Ospina Medical, evaluation begins with a detailed history and physical examination. The physician may ask where the pain is located, what movements make it worse, what treatments have already been tried, and whether the pain began after injury, pregnancy, surgery, athletic activity, or gradual wear and tear.

Certain physical exam maneuvers can help determine whether the SI joint is likely involved. These tests place gentle stress on the SI joint to see whether they reproduce the patient’s familiar pain. Imaging may also be reviewed to evaluate the lower back, pelvis, hips, and surrounding structures. However, imaging alone does not always prove that the SI joint is the pain generator. Many patients have imaging findings that do not fully explain their pain, which is why the clinical exam matters.

A diagnostic SI joint injection may be recommended when the SI joint is suspected as the source of pain. During this procedure, medication is placed into or near the SI joint using image guidance. The diagnostic portion of the injection helps determine whether numbing the area significantly reduces the patient’s typical pain. If the patient experiences meaningful relief during the expected window of the anesthetic, it supports the SI joint as a likely pain source.

SI joint injections may also be therapeutic. In addition to local anesthetic, a corticosteroid may be used to help reduce inflammation and calm the irritated joint. The amount and duration of relief can vary from patient to patient. Some patients experience temporary relief that helps them participate more comfortably in physical therapy and strengthening. Others may need additional treatment depending on the underlying cause of pain and how the joint responds.

When SI joint pain returns after injections or conservative care, radiofrequency ablation may be considered for certain patients. Radiofrequency ablation, also called RFA, uses controlled heat to target small sensory nerves that carry pain signals from the painful area. For SI joint pain, the goal is to reduce pain signaling from the nerves around the joint. RFA does not fuse the joint or change the structure of the pelvis. Instead, it focuses on interrupting pain signals so the patient may function with less discomfort.

The best treatment plan depends on the patient. Some patients improve with physical therapy, activity modification, strengthening, anti inflammatory strategies, or guided injections. Others may need a more advanced interventional approach. In rare or severe cases, surgery may be discussed, but many patients are first managed with less invasive options.

A key part of SI joint care is addressing the mechanics around the joint. The SI joint works closely with the lumbar spine, hips, glutes, core, and pelvic stabilizing muscles. If weakness, stiffness, altered gait, or poor movement patterns are contributing to irritation, procedures alone may not be enough. A strong treatment plan often combines pain relief with rehabilitation so patients can build better long term support around the joint.

Patients should seek evaluation if pain near the lower back, buttock, or back of the hip persists, worsens, or keeps returning despite rest and conservative care. Pain that limits walking, sleep, stairs, work, or exercise deserves a closer look. SI joint pain is treatable, but it must first be correctly identified.

At Ospina Medical, we use a patient centered approach to determine whether pain is coming from the SI joint, lumbar spine, hip, muscles, or another source. By combining physical examination, imaging review, diagnostic injections, and individualized treatment planning, we help patients move toward answers instead of guessing.

If you are experiencing lower back, buttock, or posterior hip pain, an evaluation can help determine whether the SI joint may be part of the problem and which treatment options may be right for you.