A patient describes pain in the buttock that travels down the back of the thigh. It is worse getting out of a
car and worse after walking. Someone says the word sciatica, a lumbar MRI is ordered, degenerative change is
found, and treatment is aimed at the spine for the next several months.
Sometimes the problem was the hip joint the entire time.
Why the hip refers pain into the buttock
The textbook presentation of hip osteoarthritis is groin pain, and when that is what a patient describes the
diagnosis is usually straightforward. The difficulty is that the hip joint is supplied by branches of several
nerves, and its pain does not confine itself to the textbook location. Buttock pain is a recognized presentation.
So is pain referred down the anterior or lateral thigh toward the knee.
What the hip joint does not typically do is produce symptoms below the knee, or numbness and tingling in a
dermatomal pattern, or foot weakness. Those findings point toward a nerve, and they are worth asking about
specifically because patients do not volunteer them.
The examination that separates them
This is where the distinction is usually made, and it takes a few minutes rather than a scan.
- Hip range of motion, compared side to side. Internal rotation is the sensitive one. A hip
that is restricted and painful at end range is behaving like a joint problem. - What provokes it. Pivoting, rotation and weight-bearing implicate the joint. Sustained
sitting, spinal flexion or extension, and coughing implicate the spine or the deep gluteal space. - Where it stops. Pain that ends at the knee behaves differently from pain that runs into the
calf and foot. - Neurologic examination. Reflexes, strength and sensation. A joint does not cause a
diminished ankle reflex. - Gait. An antalgic pattern with a shortened stance phase on one side is a joint sign.
Why imaging does not close the question
Both candidate structures have the same evidentiary problem: they look abnormal in people who feel fine.
Degenerative change on a lumbar MRI is near-universal past forty, and radiographic hip arthritis is common in
people with no hip complaint at all. Two scans, two plausible findings, and no answer about which one is
generating the pain.
That is not an argument against imaging. It is an argument for reading imaging as a list of candidates rather
than as a verdict, which is the discipline that gets skipped when a scan finally shows something after months of
uncertainty.
Where the deep gluteal muscles fit
The hip joint and the lumbar spine are not the only two options. Deep gluteal syndrome covers compression of
the sciatic or pudendal nerve by non-discogenic pelvic causes and includes piriformis syndrome, gemelli-obturator
internus syndrome, ischiofemoral impingement and proximal hamstring syndrome — and the review that
consolidated the group notes it has often been undiagnosed or mistaken for other conditions.1
Ischiofemoral impingement is worth singling out here, because it sits at the boundary of this article’s
question: it is narrowing of the space between the ischium and the lesser trochanter, so it is a hip-region
problem that produces buttock pain and behaves like neither a joint nor a disc.
How the question actually gets answered
When examination points clearly at one structure, treatment follows. When it does not — and with two or
three plausible candidates coexisting, it often does not — a targeted, image-guided diagnostic injection is
the tool that assigns the pain. Local anesthetic placed accurately into one structure answers a question that no
scan answers: with this specific thing silenced, does your pain change?
That approach carries more weight here than it would elsewhere, because for the deep gluteal candidates
there is no confirmatory test at all — no well-accepted study establishes piriformis syndrome, and
electrodiagnostic testing is used to exclude a lumbar root lesion rather than to confirm the muscle.2
When nothing rules a diagnosis in, a careful response to a targeted block is the closest thing available.
Done into the hip joint, a clear response implicates the joint. Done into the piriformis, a clear response
implicates the muscle. And a well-placed injection that changes nothing removes a candidate from the list, which
is progress even though it does not feel like it.
The failure mode to avoid
The costly pattern is not choosing wrong initially. It is never revisiting the choice. If a spinal procedure
was performed on the strength of an MRI finding and the leg pain is unchanged afterward, that outcome is
information about the diagnosis, and the productive next step is re-examination rather than a repeat of the same
treatment.
Frequently asked questions
Can hip arthritis cause sciatica-like pain down the leg?
Yes, and it is one of the more common reasons a sciatica diagnosis turns out to be wrong. Hip joint pain is classically described in the groin, but a substantial number of people with an arthritic hip report it in the buttock, and some describe it running down the thigh toward the knee. What it usually does not do is travel below the knee into the foot, or produce numbness and tingling in a nerve distribution — those point back toward a nerve cause. Learn more: the deep gluteal differential.
What is the difference between hip pain and sciatica?
The most useful separations are mechanical rather than descriptive. Hip joint pain tends to track with weight-bearing and rotation — pivoting, getting out of a car, putting on socks and shoes — and hip range of motion is restricted and painful, particularly internal rotation. Nerve-driven leg pain is more likely to follow a band down the leg, to extend below the knee, to include numbness or tingling, and to change with spinal position rather than with hip rotation. Learn more: the structures that actually generate leg pain.
Can you have hip arthritis and a disc problem at the same time?
Frequently, and this is where single-diagnosis thinking causes the most trouble. Both conditions become more common with age, so an adult over sixty may genuinely have degenerative change in the lumbar spine and an arthritic hip simultaneously. The question is not which one exists, it is which one is generating the pain you actually came in with — and when both are present, a diagnostic injection into one of them is often the cleanest way to find out. Learn more: what a diagnostic injection result tells you.
Does an X-ray of the hip settle it?
It helps, and it does not settle it. Radiographic arthritis is common in people who have no hip pain at all, so a film showing joint space narrowing does not establish that the joint is your pain generator any more than a degenerative lumbar MRI establishes that the disc is. Imaging narrows the list. The examination and the response to a targeted injection are what assign the pain. Learn more: hip joint injection.
Why did my back surgery or epidural not help my leg pain?
One possibility worth taking seriously is that the target was wrong. If leg pain persists unchanged after a well-performed spinal procedure, that is a meaningful result: it argues against the structure that was treated and in favor of re-examining the hip joint, the sacroiliac joint and the deep gluteal muscles. Repeating the same spinal treatment because it should have worked is the most common way this gets prolonged. Learn more: how a diagnostic injection is performed.
To discuss your own case, request an appointment through the appointment request form, call (314) 481-5000, or text (314) 886-5902. You can review the full range of pain treatments, read about the pain management doctors in St. Louis, or find both offices on the locations page.
Sources
- Park JW, Lee YK, Lee YJ, Shin S, Kang Y, Koo KH. “Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain.” The Bone & Joint Journal. 2020;102-B(5):556–567. doi:10.1302/0301-620X.102B5.BJJ-2019-1212.R1
- Lo JK, Robinson LR. “Piriformis syndrome.” Handbook of Clinical Neurology. 2024;201:203–226. doi:10.1016/B978-0-323-90108-6.00002-8
Dr. Gurpreet Singh Padda, MD, MBA, MHP
