Piriformis Syndrome

Assessment presentationII.2

Introduction Piriformis syndrome is neuromuscular disorder that occurs when the piriformis muscle compresses or irritates the sciatic nerve-the largest nerve in the body.

Compression of the sciatic nerve causes pain-frequently described as tingling or numbness-in the buttocks and along the nerve, often down to the leg.

The pain may worsen as a result of sitting for a long period of time, climbing stairs,

walking, or running

* This syndrome remains controversial because, in most cases, the diagnosis is clinical,

and no confirmatory tests exist to support the clinical findings

Important to remember!!

Incidence and etiology

• 6:1 prevalent in females than in males could be to the anatomic variation of the female pelvis Likewise, women tend to have a greater Q angle.

•no dominant etiological factors have been reported

• minor trauma to the buttocks or pelvis The trauma is thought to precipitate a spasm of the piriformis muscle, which subsequently inflames the adjoining sciatic nerve

Piriformis anatomy The piriformis muscle is flat, pyramid-shaped, and oblique.

This muscle originates to the anterior of the S2-S4 vertebrae, the sacrotuberous ligament, and the upper margin of the greater sciatic foramen.

This muscle passes through the greater sciatic notch and inserts on the superior surface of the greater trochanter of the femur.

With the hip extended, the piriformis muscle is the primary external rotator; however, with the hip flexed, the piriformis muscle itself becomes a hip abductor.

This muscle is innervated by branches from L5, S1, and S2.

The drawing shows the important anatomy of the PS,and how a certain leg positions pull the PM up against the sciatic nerve causing buttocks pain and radiating leg pain

Causes Trauma to the buttocks or gluteal region is the most common cause 50% of all cases

Bleeding in and around the piriformis muscle forms a hematomaThe piriformis muscle begins to swell and put pressure on the sciatic nerve

•The piriformis muscle become tight or get in to spasm

•Bilateral piriformis syndrome due to prolonged sitting during an extended neurosurgical procedure

•Bad posture

•lumbar lordosis and hip flexor tightness predisposes one to increased compression of the sciatic nerve against the sciatic notch by a shortened piriformis

•Muscle anomalies with hypertrophy can be cause by asymmetry of the muscle, Muscle spasm may change the shape and hardness of a muscle.

•Scarring in the region of the ischial tuberosity, a pelvic mass like Endometriosis near the greater sciatic notch, aneurysm of the superior or inferior gluteal artery, or anatomical variations of these vessels can all compress the nerve and lead to the syndrome.

Axial T1-weighted MR image showing asymmetry in the size of the piriformis muscles. This may reflect either hypertrophy on the right or atrophy and spasm on the left. Muscle spasm may change the shape and hardness of a muscle.

Causes

Symptoms • shooting pain from the buttock along the

posterior part of the thigh to the lateral part of foot

• symptoms seem to get worse during prolonged sitting, car driving, and going up inclines

• Palpation in the buttock region shows tenderness

Predisposing Factors

• Morton’s foot may be a factor for piriformis tightness as it will change the gait pattern

• 15 % of the population has the sciatic nerve passing through the piriformis muscle making them prone for PS

Case study A 32 years old single female presented to the clinic complaining of left hip and buttock pain.

2 months ago, the patient fell down the stairs (10 stairs) on her buttock

Complained on localized left buttock pain that radiated to her left hip and at times, midway down her left thigh.

After sitting for 1 hour or more, the pain was worse and occasionally she noted numbness in the left lateral thigh with paresthesia down the posterior aspect of the calf.

Next page physical examination of the patient

Differential diagnoses

Lumbar disc herniation Sacroiliac joint dysfunction Hamstring syndrome Coxofemoral pain

physical examination

•Palpation of buttocks•ROM inspection of the trunk and lumbar spine•Resistence test in abduction and lateral rotation of the hip•Slump test •Straight leg raising• left buttock pain was elicited upon left hip flexion and internal rotation of left hipFreiberg’s sign: Pain with passive medial rotation of the extended hip causes a stretch of the piriformis muscle•Piriformis test •Relaxed hands run over the skin around the sciatic nerve distribution indicating alteration of sensation•In disc herniation the Achilles tendon reflex is weak or absent

Outcomes of Assessment

• Full range of motion, flexion, and extension of the trunk and lumbar spine

• Palpation of buttocks painful and tense• Weakness in abduction and lateral rotation of the hip• Slump test negative• Left buttock pain was elicited upon left hip flexion and

internal rotation of left hip• Positive Lasèque’s sign (the medial rotated and

adducted hip the straight leg is raised, than foot dorsiflexed, followed by lifting up the chin) with pain in the leg

• Piriformis test positive• Achilles Tendon reflex ???

…rule out diff.diagnoses

• Stressing the sacrospinous and sacrotuberous ligaments is pain free

• The SIPS move equal during nutation/ counter- nutation

• Slump test, sneezing, coughing causes no pain• Usually referred pain from coxofemoral

conditions do not go below the knee joint and the ROM of the hip would be decreased

Treatment Goals

• Relax muscle spasm

• Decrease pain

• Rest

• Ice

• Physiotherapy (Electrotherapy, stretching)

• Medication

• Injections

Piriformis Stretching

CONCLUSION

• Controversy about piriformis syndrome and its actual existence

• Estimated at 6 % to 8% of low back pain • We could not find enough evidence in an

article that states an established pathology to validate the existence of piriformis syndrome. Therefore we believe that more research has to be done in order to justify this percentage.