Piriformis Syndrome / Deep Gluteal Syndrome (DGS) | Diagnosis & Treatment

Introduction

Deep gluteal syndrome, abbreviated as DGS is defined as pain in the buttock area caused by a non-discogenic entrapment of the sciatic nerve in the subgluteal space.

The piriformis muscle runs from the sacrum to the hip joint. Due to the fact that the sciatic nerve runs underneath it, it was suggested that a tight piriformis might compress the sciatic nerve and cause pain in the buttock and the back of the leg. Researchers have even found anatomic variations where the sciatic nerve runs directly through the muscle, leaving the sciatic nerve even more susceptible in theory. On the other hand a study by Bartret et al.  (2018) examined 1039 adult hips on MRI of which around 20% had sciatic nerve variants that might make the sciatic nerve more susceptible to compression by the piriformis muscle. They found no relationship between sciatic nerve variants and piriformis syndrome.

There are more anatomic structures that could potentially compress the sciatic nerve like the gemelli-obturator internus complex, the hamstring muscles, fibrous bands containing blood vessels, vascular abnormalities and space-occupying lesions. For this reason, experts now prefer the term “deep gluteal syndrome”.

Epidemiology

The prevalence of piriformis syndrome is not well-established, and estimates vary. Piriformis syndrome is considered a relatively rare condition compared to other causes of sciatic nerve compression or irritation

In patients who do actually suffer from real sciatica, only 6-8% are thought to have piriformis syndrome (Stafford et al. 2007). This means that in the vast majority of cases, there will be different underlying reasons for sciatica, mainly nerve root compression due to lumbar disk herniations or foraminal stenosis.
We have written a whole blog article about it covering this discussion if you would like to learn more.

Clinical Picture

Commonly reported symptoms of deep gluteal syndrome include hip or buttock pain and tenderness in the gluteal and retro-trochanteric region. The pain is often described to be sciatica-like, often unilateral, and exacerbated with rotation of the hip in flexion and knee extension. Other symptoms include intolerance of sitting more than 20 to 30 minutes, limping, disturbed or loss of sensation in the affected extremity, and pain at night getting better during the day.

Physical Examination

Several orthopedic tests are described to assess for DGS, but most of them have not undergone diagnostic accuracy studies. For this reason, their use is questionable. This is also the reason why DGS remains a diagnosis of exclusion. So before you conduct any of the following tests, make sure you have examined and excluded more prevalent pathologies in the lumbar spine and SI joint that could explain the patient’s symptoms.

The only study evaluating the diagnostic accuracy of different tests for DGS is a study by Martin et al. (2014).

the seated piriformis stretch test had a sensitivity of 52% and a specificity of 90% in the diagnosis of endoscopically confirmed sciatic nerve entrapment. This is the only study evaluating this test yet, which is why we give this test a moderate clinical value to confirm the condition in practice. According to this study, the active piriformis test had a sensitivity of 78% and a specificity of 80% in the diagnosis of endoscopically confirmed sciatic nerve entrapment. This is the only study evaluating this test yet, which is why we give this test a moderate clinical value to in and exclude the condition in practice.

The Seated Piriformis Stretch Test is another test that was evaluated by Martin et al. (2014), the seated piriformis stretch test had a sensitivity of 52% and a specificity of 90% in the diagnosis of endoscopically confirmed sciatic nerve entrapment. This is the only study evaluating this test yet, which is why we give this test a moderate clinical value to confirm the condition in practice.

Other orthopedic tests for deep gluteal syndrome are:

• Freiberg Sign
• Pace Test
• Beatty Maneuver
• FAIR Test
• Heel Contralateral Knee Maneuver (HCLK) Maneuver

Treatment

There is quite a variety of options targeted at short-term pain relief like manual pressure and massage in the painful area, dry needling, heat, and rolling with a foam roller or tennis ball. Another short-term option is to stretch the deep gluteal muscles. Here are 2 stretches that you might want to try at home:

1. Yoga pose
2. Standard piriformis stretch in sitting or supine

While those are all “optional”, our recommendation for short-term pain relief is to decrease activities that are aggravating your buttock pain. Avoid prolonged sitting or standing and try to change positions as often as possible as our muscles don’t like static postures. Sitting on a well-cushioned pillow can make sitting a bit more bearable and having a pillow between your legs when you’re lying in bed can reduce prolonged stretch on the gluteal muscles. If running or walking is painful, temporarily decrease your running or walking volume to tolerable levels.

As mentioned in other videos, the only real long-term solution to muscle pain is a progressive exercise program that targets the painful area. With all exercises, make sure that pain levels are tolerable during the program. If pain increases afterward, make sure the pain settles within 24 hours. If this is not the case, try easier exercises or decrease the number of sets and reps. Here’s an example of a progressive exercise program starting from easy to more advanced exercises:

1. Clam Shells 🡪 Add resistance bands 🡪 side plank clamshell
2. Fire hydrants in sitting 🡪 quadruped🡪 standing with resistance band
3. Glute bridges 🡪 1 legged
4. Horse kicks

If these exercises are tolerable, you can move on to heavier more global exercises such as:

1. Side lying abduction with the ball against the wall
2. Leg Presses
3. Squats
4. Hip thrusts

Would you like to learn more about Piriformis Syndrome / Deep Gluteal Syndrome or other pathologies mimicking it? Then check out the following resources:

• Pain in the Butt – Why it’s not Piriformis Syndrome
• Referred Pain, Nociceptive Pain, Or A Radiculopathy?
• Podcast Episode 036 – Hip Pathologies with Mehmet Gem

References

Bartret, A. L., Beaulieu, C. F., & Lutz, A. M. (2018). Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome. European radiology, 28, 4681-4686.

Martin, H. D., Kivlan, B. R., Palmer, I. J., & Martin, R. L. (2014). Diagnostic accuracy of clinical tests for sciatic nerve entrapment in the gluteal region. Knee Surgery, Sports Traumatology, Arthroscopy, 22, 882-888.

Stafford, M. A., Peng, P., & Hill, D. A. (2007). Sciatica: a review of history, epidemiology, pathogenesis, and the role of epidural steroid injection in management. British journal of anaesthesia, 99(4), 461-473.