Is Your Sciatica Really Coming From Your Back?

Your buttock aches. Your leg burns or tingles. An MRI shows a bulging disc, and it seems like you finally have an answer.

But does that disc actually explain your symptoms?

Sometimes it does. Sometimes the source is a nerve irritated farther along its path, near the buttock, the rim of the pelvis, or the outside of the knee. These problems can resemble pain from the spine and deserve a place in the examination. Research on sciatic nerve entrapment, cluneal nerve research, and a fibular nerve case report document these possibilities.

I spent seven years working at Anesthesiology and Pain Consultants at Lafayette Surgical. During that time, I treated many patients who continued to hurt after back and neck surgery, sometimes described as having “failed back” or “failed neck” surgery.

In some of the patients I treated, a peripheral nerve problem was an important source of pain that had been attributed to the spine. Those experiences reinforced a lesson that still shapes how I approach patients: we need to examine the nerves beyond the back, even when a scan already shows a disc problem.

Persistent pain after surgery does not, by itself, prove that an operation was unnecessary. It does give us a reason to reassess where the remaining symptoms are coming from.

More common than many people expect.

A 2015 systematic review combined 33 studies involving 3,110 people without symptoms. It estimated the following rates of disc bulges on spine imaging:

These are age-specific estimates from studies using MRI or CT. They show that a disc bulge can be present without causing pain. Brinjikji and colleagues, 2015; published age-by-age estimates.

These numbers are not the percentage of patients who are misdiagnosed. A 60% rate at age 50 does not mean there is a 60% chance your diagnosis is wrong. The review did not measure how often clinicians mistakenly blamed a bulge for someone's leg pain.

There is no single reliable percentage from this research that answers that question. The practical lesson is to match the scan with your symptoms and examination before deciding what needs treatment.

A nerve root is the starting portion of a nerve near the spine. Irritation there can cause radicular pain, meaning pain arising from a spinal nerve root.

Nerves also travel through the pelvis, buttock, and leg. A nerve compressed farther along that route can cause peripheral nerve entrapment. This may produce radiating pain, tingling, numbness, or weakness that resembles a low-back problem. The symptom patterns can overlap, which is why their location alone does not settle the diagnosis. Clinical discussion of fibular neuropathy and L5 radiculopathy.

Here are three areas worth checking.

The common fibular nerve, also called the common peroneal nerve, wraps around a bony area just below the outside of your knee called the fibular head. Its exposed position makes it vulnerable to pressure.

Irritation here can cause:

Burning or tingling along the outer lower leg and top of the foot.

Numbness in those areas.

Difficulty lifting the foot or toes, sometimes called foot drop.

Prolonged leg crossing, repeated squatting, an injury, or pressure from a brace can contribute. Symptoms can resemble an L5 nerve-root problem in the low back. An examination of strength and sensation, sometimes supported by electrical nerve testing, can help distinguish them. Research on fibular nerve entrapment.

A published case report described a patient who underwent lumbar decompression without relief before an overlooked fibular nerve problem was identified. One case cannot tell us how frequently this happens, but it illustrates why checking this nerve matters. Reife and Coulis, 2013.

The piriformis is a small muscle deep in the buttock, close to the sciatic nerve. Irritation or compression of the sciatic nerve in this region can produce buttock pain and symptoms traveling down the leg.

Possible clues include a deep buttock ache, difficulty sitting comfortably, and symptoms aggravated by certain hip positions.

You may hear this called piriformis syndrome. Clinicians also use the broader term deep gluteal syndrome, because other tissues in the same area can affect the sciatic nerve. A sore piriformis does not automatically establish nerve entrapment. Research on deep gluteal syndrome.

Specific hip examination tests can help investigate this possibility, but no single maneuver gives the whole answer. The spine, hip, and surrounding nerves all need consideration. Study of clinical tests for sciatic nerve entrapment.

The cluneal nerves are small nerves that provide feeling to the buttock region. The superior cluneal nerves cross the upper rim of the pelvis, near the back of your beltline, where they can become irritated or trapped.

Possible clues include pain across the low back or upper buttock and a tender spot along that bony rim that reproduces familiar symptoms when examined. These are sensory nerves, so isolated cluneal entrapment should not explain true muscle weakness or foot drop. Cluneal nerve anatomy and clinical features.

Although these nerves supply the buttock skin, associated pain or tingling can extend into the leg and resemble sciatica. In a prospective study of 834 patients with low-back pain and/or leg symptoms, 113—about 14%—met the researchers' criteria for suspected superior cluneal nerve disorder. Nearly half of that group also had leg symptoms. These findings describe that particular clinical population, not everyone with back pain. Kuniya and colleagues, 2014.

Yes. A person can have a nerve-root problem in the low back and a compressed peripheral nerve farther down the same pathway. This combination is often called double crush syndrome.

For example, L5 nerve-root compression and fibular nerve entrapment near the knee can coexist. A 2025 case series described 14 patients with that combination. Treating one location may leave symptoms from the other. Lower-limb double crush case series.

The theory that compression at one site makes the nerve more vulnerable at another remains debated. An MRI bulge plus leg pain is not enough to establish double crush; evidence for both problems matters. Research discussing the double crush hypothesis.

In some patients, the peripheral nerve is the main source of symptoms and the disc finding is incidental. In others, the spine is responsible, or both contribute. The studies above do not establish that peripheral entrapment causes most sciatica.

Bring your imaging report, but also be ready to describe exactly where symptoms travel, which positions bring them on, and what prior treatment changed.

The evaluation should compare that history with strength, reflexes, sensation, and examination of the relevant areas along the nerve's path. When needed, EMG and nerve-conduction studies—electrical tests of muscles and nerves—or targeted ultrasound can help locate a fibular nerve problem. Diagnostic approaches to fibular neuropathy.

For suspected cluneal entrapment, a carefully targeted local-anesthetic block may help support the diagnosis when interpreted alongside the examination. Cluneal nerve evaluation.

A useful question to ask your clinician is: “What findings show that my pain is coming from this disc, and have the nerves farther down my leg been checked?”

New difficulty urinating, loss of bladder or bowel control, numbness around the groin or buttocks, or rapidly worsening leg weakness requires emergency evaluation. New foot drop also needs prompt medical assessment. NHS guidance on urgent sciatica symptoms and guidance on timely fibular nerve diagnosis.

When pain keeps you from sitting through work, walking comfortably, or enjoying time outdoors in Acadiana, you deserve an evaluation that connects the findings to your everyday symptoms.

At Relief Plus, my experience with patients who continued to hurt after spine surgery informs the questions I ask today. If you have persistent buttock or leg pain, bring your history and imaging reports so we can discuss whether the spine, a peripheral nerve, or a combination needs further evaluation.

Contact Relief Plus to schedule an evaluation for persistent hip, buttock, or leg pain.