Piriformis Syndrome

Other Names

• Piriformis Syndrome (PS)
• Piriformis Muscle Pain
• Piriformis Dysfunction
• Deep Gluteal Syndrome
• Posterior Gluteal Myofascial Pain Syndrome
• Primary Piriformis Syndrome
• Nonlocalizing sciatica
• Extra-spinal sciatica
• Wallet neuritis
• Hip socket neuropathy

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Background

• This page refers to piriformis syndrome (PS)
  • Sciatica has multiple causes and is discussed separately

History

• First described by Yeoman in 1928
• First proposed as a cause of sciatic pain by Freiberg in 1934
• The term "piriformis syndrome" was coined by Robinson in 1947

Epidemiology

• Females to male ratio is about 6:1
• Prevalence
  • Annual prevalence estimated to be between 2.2% and 19.5%
  • Lifetime between 12% and 27%
• Relationship to Sciatica
  • Only about 6-8% of all cases of sciatica are due to piriformis syndrome
  • One study estimates piriformis syndrome causes 67.8% of non-disc sciatica

Demographics

• More common in women age 30 to 40
• Female to male ratio is 3:1

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Introduction

Diagram showing relationship of the piriformis muscle and sciatic and pudendal nerve. a= Pyriformis, b= Sciatic Nerve, c= Posterior Femoral Cutaneous Nerve, d= Pudendal Nerve, e= Nerve to Obturator Internus

Illustration of the piriformis anatomy

Causes of nondisc sciatica

General

• Occurs as a result of neuromuscular conflict due to the close proximity of the piriformis muscle and sciatic nerve
• Classified as an entrapment neuropathy causing compression of the sciatic nerve by the inflamed or hypertrophied piriformis muscle
• Patients endorse pain radiating from the buttocks down the posterolateral thigh

Etiology

• Trauma to piriformis muscle
• Piriformis muscle hypertrophy often seen in athletes
• Piriformis muscle spasm
• Sitting for prolonged periods of time (officer workers, bicyclists, taxi or truck drivers)
• Anatomic variants (see: Piriformis)
  • Described in more detail on the piriformis page
• Entrapment of the sciatic nerve
  • Typically seen between greater sciatic notch and ischial tuberosity
  • Can also occur at the lower ischial tunnel, the hamstring muscle attachment, and quadratus femoris muscle

Anatomy of Piriformis Muscle

• The piriformis muscle is anatomically adjacent to the sciatic nerve at the sciatic notch
• ~15% of individuals have abnormal relationship between piriformis muscle and Sciatic Nerve
• Abnormal anatomy may not increase risk of developing piriformis syndrome

Associated Conditions

• Sciatica
  • In approximately 15-20% of individuals, the sciatic nerve tracks through the body of the Piriformis muscle
  • However, only about about 6-8% of all cases of sciatica are due to piriformis syndrome
• Chronic Back Pain
  • Piriformis syndrome present in 6% to 17.2% of patients with chronic back pain
• Pudendal Neuralgia
  • Occurs due to entrapment of the pudendal nerve at the inferomedial border of the piriformis at the greater sciatic notch

Controversy

• Considered mildly controversial
• Of 29 surveyed physiatrists, only 21 believed that condition exists
• Some authors argue that sciatica must be present to diagnose piriformis syndrome

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Risk Factors

• Generally, poorly understood
• Anatomic risk
  • Only known when patient is imaged or undergoes surgery
• Female gender
  • Wider quadriceps femoris angle in the os coxae
  • Hormone changes during pregnancy

Sports

• Limited to case reports
• Soccer
• Rugby
• Running

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Differential Diagnosis

Differential Diagnosis Piriformis Syndrome

• Lumbosacral radiculopathies
• Intervertebral disc pathology
• Compression fractures
• Spinal stenosis
• Facet syndrome
• Primary sacral dysfunction
• Sacroiliitis
• Greater Trochanteric Pain Syndrome

Differential Diagnosis Hip Pain

• Fractures And Dislocations
  • Pelvic Fracture
  • Hip Fracture
  • Acetabular Fracture
  • Femoral Neck Stress Fracture
  • Pelvic Stress Fracture
  • Hip Dislocation
• Arthropathies
  • Osteitis Pubis
  • Avascular Necrosis of the Hip
  • Hip Osteoarthritis
  • Femoroacetabular Impingement
  • Transient Osteoporosis of the Hip
  • Hip Microinstability
  • Osteochondral Defect of the Hip
• Muscle and Tendon Injuries
  • Hip Flexor Tendonitis
  • Piriformis Syndrome
  • Hamstring Strain
  • Proximal Hamstring Tendinopathy
  • Adductor Strain
  • Greater Trochanteric Pain Syndrome
• Bursopathies
  • Iliopsoas Bursitis
  • Ischial Bursitis
• Ligament Injuries
  • Acetabular Labrum Tear
• Neuropathies
  • Meralgia Paresthetica
• Other
  • Snapping Hip Syndrome
  • Septic Arthritis
  • Gout
  • Leg Length Discrepancy
• Pediatric Pathology
  • Transient Synovitis of the Hip
  • Developmental Dysplasia of the Hip (DDH)
  • Legg-Calve-Perthes Disease
  • Slipped Capital Femoral Epiphysis (SCFE)
  • Avulsion Fractures of the Ilium (Iliac Crest, ASIS, AIIS)
  • Ischial Tuberosity Avulsion Fracture
  • Avulsion Fractures of the Trochanters (Greater, Lesser)
  • Iliac Apophysitis (AIIS, ASIS, Iliac Crest)
  • Idiopathic Chondrolysis of the Hip

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Clinical Features

Common physical exam findings in piriformis syndrome

Special tests for iriformis syndrome

History

• Patients describe a aching pain in their buttocks
• Pain starting from the hip and lower back descending/ radiating down the posterolateral thigh as far as the ankle
  • This spares and does not reach the toes
  • Follows the course of the sciatic nerve
• Pain is often described as burning, numbness or tingling
• Aggravated by prolonged sitting and walking

Physical Exam: Physical Exam Hip

• Tenderness to deep palpation of the piriformis is identified in 92% of cases
• Patient may be tender to palpation of the greater sciatic notch
• There may be a a palpable, tender, sausage‐like mass or fibrous bands over the piriformis muscle
• Although not routinely recommended, pain is reproducible with palpation of the piriformis during a rectal or vaginal exam

Special Tests

• FADIR Test: Flexion, adduction, internal rotation
• Beatty Test: Patient in lateral decubitus position, flexes, abducts leg against gravity
• Active Piriformis Test: Similar to beatty test however abduction and externally rotate against resistance
• Pace Test: Patient is seated, examiner resists abduction of legs
• Straight Leg Raise Test: helpful if sciatica features, patient supine raise leg with knee in extension, typically negative in PS
• Seated Piriformis Stretch Test: helpful if sciatica features, patient seated, flex leg, knee extended, internally rotate and adduct
• Freibergs Sign: Patient is prone, ipsilateral leg is extended and internally rotated
• Passive Piriformis Stretch Test: lateral decubitus position, passively internally rotate and flex hip
• Solheims Sign: Pain with adduction of the flexed thigh

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Evaluation

MRI of hip labeled

Long axis sonogram of the piriformis (red arrows). Left is abnormal and thickened compared to the asymptomatic side on the right

General

• The diagnosis and even definition of piriformis syndrome remain challenging
• There is a lack of standardized tests or definitive pathophysiology
• Diagnosis is made through a combination of history, physical exam and testing

Radiographs

• Standard Radiographs Hip
  • Typically normal

MRI

• Imaging modality of choice if there is diagnostic uncertainty
• May need to image lumbar spine to clarify etiology
• Consider MR neurography which suppresses signal from surrounding tissue
  • Can be helpful in unclear cases
  • In one study, 86% of patients had abnormal signal in the ipsilateral sciatic nerve
  • In a second study of 239 patients in which diagnosis was uncertain, MR neurography identified edema of the ipsilateral sciatic nerve in 94% of patients
• Findings
  • Enlargement of the piriformis muscle

CT

• Alternative option if MRI unavailable

Ultrasound

• Sonopalpation with dynamic ultrasound can be utilized for more accurate assessment of the painful muscle
  • Piriformis is relatively small, deep muscle can be hard to palpate
  • May identify other causes of pain including gluteal muscles, external rotators
• May be helpful to assess the sciatic nerve cross-sectional area, but more research is needed
• Potential findings
  • Enlarged piriformis, sciatic nerve compared to unaffected side
  • Decreased echo intensity, unclear perineurium

EMG/NCS

• Often normal, may be used to exclude other conditions or causes of radiculopathy
• Fishman et al found a delay in the H reflex on EMG in the FAIR position (described below) in patients with PS compared to asymptomatic controls

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Classification

Clinical Scoring System

Classification	Point
Unilateral or bilateral buttock pain with fluctuating periods of pain through the day	1
No lower back pain	1
No pain upon palpation of axial spine	1
Negative result for Straight Leg Raise	1
Prolonged sitting triggers gluteal pain or sciatica	1
Fluctuating sciatica through the course of the day	1
Positive FAIR or Freiberg sign	1
Positive Beatty sign	1
Positive Palpation	1
Sciatica reproduced by Fair or Freiberg test	1
Sciatica reproduced by Beatty test	1
Absence of perineal irradiation	1

• Proposed by Michael et al
  • Score of 8 or greater is probably PS
  • Score of 7-8 makes diagnosis unlikely
  • Score under 6 should consider another diagnosis

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Management

Needle tip is seen injecting into piriformis muscle a safe distance from the sciatic nerve

Nonoperative

• Medications
  • NSAIDS
  • Muscle Relaxants
  • Neuropathic Analgesics (consider carbamazepine, baclofen, gabapentin, and pregabalin)
• Physical Therapy
• Manual Therapy
  • Consider dry needling, acupuncture, manual overpressure, and massage

Procedure: Piriformis Injection

• Can be diagnostic and therapeutic
• Ultrasound guidance is up to 95% accurate, fluoroscopy or landmark based approach is only 30%
• Filler et al performed 162 MRI guided piriformis muscle injections
  • 15% had complete relief (no recurrence), 8% had 2-4 months of relief with lasting relief after a repeat injection
  • 37% had 2-4 months of relief with a subsequent recurrence, 24% had less than 2 weeks of relief with subsequent recurrence, and 16% had no relief
• Misirlioglu et al injected 57 patients with either lidocaine or lidocaine plus betamethasone under US guidance
  • Both groupes experienced significant reduction in pain but there was no difference between the groups

Procedure: Botulinum Toxin Injection

• Can be considered in recalcitrant cases
• Note that the medication is expensive
• Fishman et al double blinded RCT
  • Botulinum toxin superior to lidocaine plus steroids
• Fishman et al in a second study
  • Botulinum toxin injection into the piriformis muscle combined with physical therapy provided greater than 50% relief in 24 of 27 patients
  • led to a decrease in the mean Visual Analog Scale from 6.7 to 2.3

Operative

• Indication
  • Failure of conservative measures
• Technique
  • Tenotomy of piriformis muscle tendon and decompression of sciatic nerve

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Rehab and Return to Play

Piriformis Syndrome Rehab exercses

Piriformis Syndrome phased rehab

General Rehabilitation Considerations

• Piriformis muscle often has increased resting tone
• Important to target trigger points, tight bands and attempt to restore normal muscle tone
• Any protocol should include stretching exercises for the piriformis and gluteal muscle groups
• Also focus on lumbosacral stability, hip strengthening
• Correction of biomechanical errors across the hip, pelvis, and spine
• In patients with sciatica, individuals should work on nerve glide or neuroglide techniques

Rehabilitation and Return to Play Protocol for Piriformis Syndrome

• Phase 1: Acute Management (Weeks 1-2)
  • Goals: Pain reduction, inflammation control, initiate gentle mobility
  • Interventions: NSAIDS, activity modification, ice therapy, gentle stretching
  • Adjuncts: ultrasound, thermal, possible corticosteroid injection
  • Progression Criteria: Reduced resting pain, ability to perform stretches without significant symptom reproduction
• Phase 2: Subacute Rehabilitation (Weeks 3-6)
  • Goals: Restore flexibility, initiate strengthening, correct movement patterns
  • Interventions: progressive stretching program, hip strengthening, movement re-education, neuromuscular inhabitation techniques
  • Adjuncts: extracorporeal shock wave therapy, repeat injection if needed
  • Progression Criteria: Pain-free stretching, improved hip strength, normalized movement patterns during functional tasks
• Phase 3: Advanced Strengthening and Sport-Specific Training (Weeks 7-10)
  • Goals: Restore full strength, power, and sport-specific function
  • Interventions: progressive resistance training, continued stretching maintenance, gradual return to running and cutting
  • Progression Criteria: Full pain-free ROM, strength ≥90% of contralateral side, successful completion of sport-specific drills without symptoms
• Phase 4: Return to Play (Weeks 10-12)

Piriformis Syndrome Rehab Exercises PDF

• Piriformis Sciatic Nerve Stretches PDF
• Piriformis Stretch PDF
• Piriformis Syndrome Home Exercise Program PDF
• Piriformis Syndrome Patient Information Sheet PDF
• Piriformis Syndrome Rehab Exercises PDF

Return to Play/Work

• Return to play criteria
  • Complete resolution of buttock and leg pain at rest and with activity
  • Full, pain-free hip range of motion (especially flexion, adduction, internal rotation)
  • Hip strength ≥90% of contralateral limb (abductors and external rotators)
  • Restoration of sport-specific skills without symptom reproduction
  • Normalized movement patterns (minimal hip adduction/internal rotation during single-leg tasks)
  • Psychosocial readiness and confidence in affected limb
  • Ability to tolerate prolonged sitting without symptom recurrence
  • Successful completion of full-intensity practice sessions

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Prognosis and Complications

Prognosis

• In 250 patients treated with medications (NSAIDS, muscle relaxant) and physical therapy, 51.2% had resolution of symptoms
• Fishmnan et al
  • Use of physical therapy combined with corticosteroid injection
  • led to at least 50% relief in 79% of their 665 patients
• In patients treated surgically, there are small cohorts with positive results
  • Most (59-69%) report good-to-excellent results

Complications

• Chronic pain
• Disability
• Inability to return to sport
• Surgical complications include
  • Damage to sciatic nerve
  • Infection
  • Bleeding

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See Also

Internal

• Hip Pain (Main)
• Physical Exam Hip
• Hip Anatomy (Main)

External

• Sports Medicine Review Hip Pain: https://www.sportsmedreview.com/by-joint/hip/

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