Piriformis Syndrome
**Piriformis Syndrome*: A neuromuscular array of symptoms characterized by a constellation of symptoms that includes hip and buttock pain with or without sciatica1
complex of piriformis muscle dysfunction symptoms of hip and buttock pain with have radiating pain, numbness, and tingling along posterior lower extremity to the medial foot2.
RCT’s examing piriformis syndrome require radiculopathy as an eligibility criteria1.
- Piriformis Dysfunction:
- Sciatic nerve compression causing1
- Unilateral Gluteal or sacroiliac pain
- Radiculopathy
- Piriformis spasm causing:1
- Unilateral Gluteal or sacroiliac pain
- Radiculopathy
Etiology
Since this is a syndrome and not a pathology there are multiple etiologies that can result in this clinical presentation.
Abnormal Hypertrophy
Hypertrophy of the piriformis muscle can result in piriformis syndrome3. Specifically in cases where the sciatic nerve courses through the piriformis muscle belly instead of around3.
Overuse
Trauma
Direct or indirect trauma can result in piriformis syndrome3.
Indirect trauma has been noted in sacroiliac or gluteal regions which can affect the piriformis3. The resulting hematoma and/or scarring around the deep hip stabilizers and sciatic nerve can cause piriformis syndrome3.
Gender
Although not a direct factor, gender appears to play a large factor in the incidence of piriformis syndrome. Literature has demonstrated a 6:1 female-to-male ratio3.
Pseudoaneurysm of inferior gluteal artery
Ischial bursitis
“Pseudoaneurysm of the inferior gluteal artery”3 Excessive exercise to the hamstring muscles. ▶ Inflammation and spasm of the piriformis muscle. This is often in association with trauma, infection, and anatomical variations of the muscle. ▶ Anatomical anomalies. Local anatomical anomalies may contribute to the likelihood that symptoms will develop.
Hip Flexion Contracture
“Hip flexion contracture. A flexion contracture at the hip has been associated with piriformis syndrome. This flexion contracture increases the lumbar lordosis, which increases the tension in the pelvic–femoral muscles, as these muscles try to stabilize the pelvis and spine in the new position. This increased tension causes the involved muscles to hypertrophy with no corresponding increase in the size of the bony foramina, resulting in neurological signs of sciatic compression.”3
Inflammation and spasm of piriformis muscle
Pathophysiology
The piriformis is believed to act as an secondary or accessory hip abductor and extensor, supporting the primary hip extensor and abductors such as the gluteus medius or minimus4.
When the gluteus medius and minimus are dysfunctional and underactive, the piriformis can take up the slack and become overactive4. This is helpful in the short term so the person can perform their normal activities, but will cause excessive wear and tear on the piriformis in the long term.
Secondary sciatica
Patient presentation
Dutton3 listed 6 “classic” findings in patients with piriformis syndrome:
- History of trauma to the sacroiliac and gluteal regions3
- Pain along the sciatic nerve path from the sacroiliac joint, to the greater sciatic notch, to the piriformis muscle3
- Generally associated with walking
- Aggravation with stooping and/or lifting3
- A tender and palpable mass over the ipsilateral piriformis muscle3
- A positive straight leg raise3
- Gluteal atrophy, especially in severe and chronic cases3.
ROM
Strength
Differential Diagnosis
Piriformis syndrome is generally a diagnosis of exclusion3
- Hamstring injury
- Lumbosacral disc injuries
- Lumbosacral discogenic pain syndrome
- Lumbosacral facet syndrome
- Lumbosacral radiculopathy
- Lumbosacral spine sprain
- Lumbosacral spondylolisthesis
- Lumbosacral spondylolysis
- Sacroiliac joint injury/dysfunction
- Inferior gluteal artery aneurysm or pseudoaneurysm
- Malignancy/tumors
- Arteriovenous malformations
Examination
Subjective
ROM testing
Strength testing
Special test
- Ober’s test
- Active Sidelying Piriformis Test
- Seated Piriformis Test
Functional Testing
Management
Piriformis syndrome rehabilitation can be simplified into 2 primary goals:
Patient Education
Position and Posture Modification
It is important to minimize aggravating factors by educating patients to minimize positions that directly compress or excessively lengthen the piriformis4.
Manual Therapy
Manual therapy to the piriformis and surrounding musculature is suggested to help with piriformis syndrome4. Manual therapy can decrease the hypertonicity of these muscles allowing more effective stretching4.
Manual therapy can be aggravating to some patients, so be sure to apply pressure to patient tolerance and be willing to discontinue manual therapy if symptoms are worsened4
INIT
INIT was more effective than PRT in patients with piriformis syndrome1
PRT
INIT was more effective than PRT in patients with piriformis syndrome1
Stretching
Stretching can be beneficial. Stretching type, progression, and dosage is important.
Start with gradual, light stretches4.
Avoid aggressive stretching since this can irritate the tissues4.
Based on 3-D modeling the following position is best (>30-40%) for increasing piriformis length:4
- Flexion: 115-120°
- ER: 40-50°
- Adduction: 25-30°
Deep Hip Stabilizer Strengthening
Here is where you should start:
- Isometric → isotonic exercises4.
Here are functional positions that require the most deep hip stabilization:
- Single Leg
- Unsteady
- Fast
Exercise examples:
- Modified Deadlift
- At wall
- Away from wall
- Single-leg
- Airplane
Lumbopelvic Strengthening
“A concurrent presentation or history of lumbopelvic dysfunction is common in patients presenting with piriformis muscle syndrome. Lumbopelvic muscle strength and endurance exercises should be considered to provide proximal support. Patients whose clinical presentation is consistent with lumbopelvic dysfunction classification should be treated according to available CPGs that are available for low back pain.21 Following recommendations for this guideline will serve the dual purpose of providing best-practice intervention for coexisting lumbopelvic dysfunction and help determine the extent of piriformis muscle influence on the overall patient presentation.”4
Operative treatment
Operative treatments are only given to patients who do not achieve clinical improvement4. “Although most patients with dysfunction related to piriformis syndrome respond well to nonoperative treatment, options are available for those who do not achieve clinical improvement. Corticosteroid and botulinum toxin (botox) injections have been used and described in the literature as treatment for challenging cases. These treatment options may allow better tolerance to impairment-based exercise recommendations. In rare cases of continued pain and sciatic nerve symptoms associated with significant dysfunction, open or endoscopic surgical treatment may be suggested.118”4