Back Pain Doctor in Frontenac, MO

FRONTENAC, MISSOURI

Back pain patients from Frontenac, about 19 minutes away via I‑270 and Clayton Road, often arrive after a lumbar epidural did nothing. That is a common ending when the real source is the sacroiliac joint, a few inches lower and to the side. We confirm it before treating it.

Some back pain sits across the belt line. It is worse getting out of a car and worse standing on one leg. Pressing one spot beside the tailbone brings it back. That is a joint problem. It is among the most treatable causes of low back pain, and among the most often missed.

Getting here from Frontenac

Frontenac is roughly 12.4 miles from the Natural Bridge Road office, about 19 minutes via I‑270 south and Clayton Road. Patients from here often come after an epidural aimed at the lumbar spine (lower back) did nothing. That is a common ending when the actual source is a few inches lower and to the side.

Can the sacroiliac joint cause low back pain?

The sacroiliac joints connect the base of the spine to the pelvis. They move very little. That is part of why they were dismissed as a pain source for decades. Studies using controlled diagnostic blocks put them behind a meaningful share of chronic (long-lasting) low back pain. The figure commonly cited is fifteen to thirty percent in patients referred to pain clinics.

That is not a small number. Picture a room of people with lasting low back pain and normal-looking lumbar imaging. A substantial minority of them have a joint problem that no lumbar MRI will ever show.

Sacroiliac joint pain covers the anatomy and how it shows up.

What does sacroiliac joint pain feel like?

The pattern is fairly distinctive once you know to look:

• Pain centered below the belt line and to one side, often pointed to with a single finger just inside the posterior superior iliac spine (the bony bump at the back of the pelvis)
• Referred pain into the buttock and sometimes the back of the thigh, usually stopping above the knee
• Worse rising from sitting, getting out of a car, rolling over in bed and standing on the affected leg
• Often on one side only, and often clearly worse on one side than the other
• Often traced back to a fall onto the buttock, a pregnancy, a leg length difference, or a fusion above it

The one‑finger test is truly useful. Patients with sacroiliac pain point. Patients with discogenic (disc) pain sweep a hand across the low back.

How is sacroiliac joint pain diagnosed?

No imaging study confirms sacroiliac pain. Degenerative change (the joint breaking down) is common in the joint. It matches symptoms poorly, exactly as it does everywhere else in the spine.

The exam uses provocation maneuvers (tests that stress the joint): distraction, thigh thrust, compression, the sacral thrust and Gaenslen maneuver. Each one alone is unreliable. When three or more bring back the patient’s familiar pain, the odds of a sacroiliac source rise substantially. That is the threshold most clinicians use.

Definitive confirmation is an image‑guided anesthetic block into the joint. If the pain goes away for as long as the numbing medicine lasts, the joint is the source. Sacroiliac joint injection describes the procedure and what a positive result allows.

Why is sacroiliac joint pain so often missed?

Several reasons add up. Lumbar imaging is ordered first and finds something, because it always finds something in an adult. The search stops there. The provocation exam is not routinely done outside of pain and physical medicine practices. And pain spreading into the buttock and thigh reads as sciatica to anyone not examining the joint.

The most common route to this diagnosis in our practice is a patient who has had one or two lumbar epidurals with no effect. That failure is really a clue. A correctly placed epidural that changes nothing argues against the lumbar spine.

Sciatica or referred pain covers how to tell it apart from true radicular pain (pain from a pinched nerve root).

How is sacroiliac joint pain treated?

A confirmed sacroiliac source responds to a mix of targeted injection and specific rehab. The injection reduces inflammation in the joint. More important, it makes it possible to do the gluteal and core work that stabilizes the joint. Without that work, the relief tends not to last.

Some patients’ pain returns predictably after each injection. For them, radiofrequency treatment of the lateral branch nerves that supply the joint is an option with a reasonable evidence base. It works on the same principle as radiofrequency ablation in the facet joints.

Sometimes the joint is truly unstable, not just painful. That is a different problem and a surgical conversation. It is uncommon, and it should not be the first thing offered.

What Frontenac patients ask

Can an MRI show sacroiliac joint pain?

It can show inflammation in the joint, which matters for inflammatory arthritis. It can also show degenerative change, which usually does not mean much. It cannot show that the joint is the source of your pain. That takes an exam and, when needed, a diagnostic block.

Why does it hurt more on one side?

Almost everything loads the joints unevenly — a leg length difference, a habit of standing on one leg, an old ankle injury, a pregnancy. Pain on one side is the rule here, not the exception. It is one of the features that sets it apart from discogenic (disc) pain.

I had a lumbar fusion and now this started. Is that related?

Often, yes. A fusion shifts load to the segments and joints next to it. The sacroiliac joints sit directly below the most common fusion levels. New sacroiliac pain after a lumbar fusion is a recognized pattern. Failed back surgery covers the broader picture.

Will one injection be enough?

Sometimes, especially when it is paired with rehab that addresses why the joint was overloaded. When relief is real but short, that is useful information. It points toward a longer‑acting option, not toward repeating the same injection forever.

Where is sacroiliac joint pain felt?

Below the belt line and to one side, often in a spot you can point to with one finger beside the tailbone. It can spread into the buttock and sometimes the back of the thigh, usually stopping above the knee. People with sacroiliac pain tend to point to one spot. People with disc pain sweep a hand across the low back.

My lumbar epidural did not help. Could it be my sacroiliac joint?

It could. A correctly placed lumbar epidural that changes nothing argues against the lumbar spine as the source. The most common route to a sacroiliac diagnosis in our practice is a patient who has had one or two lumbar epidurals with no effect. We confirm it with provocation tests and, when needed, an image‑guided anesthetic block before treating it.

Frontenac patients rebuilding strength after a flare often start with the bridge exercise so the hips carry their share of the load.

Related reading

• Sacroiliac joint pain
• Sacroiliac joint injection
• Sciatica or referred pain
• Lower back pain on one side
• Coccydynia
• Back pain doctor for nearby Kirkwood
• Back pain care for Ladue patients