Piriformis Syndrome
• Situation where the
piriformis muscle is
compressing the sciatic
nerve resulting in
sciatic neuropathy
Piriformis Syndrome
• The PM and sciatic
nerve both exit the
pelvis through the
greater sciatic notch
Anatomic Characteristics
•
The piriformis muscle acts as an external rotator, weak abductor, and weak flexor
of the hip, providing postural stability during ambulation and standing.
•
The piriformis muscle originates at the anterior surface of the sacrum, usually at
the levels of vertebrae S2 through S4, at or near the sacroiliac joint capsule. The
muscle attaches to the superior medial aspect of the greater trochanter via a
round tendon that, in many individuals, is merged with the tendons of the
obturator internus and gemelli muscles (Figure 1).1,13,14
•
The piriformis muscle is innervated by spinal nerves S1 and S2—and
occasionallyalso by L5.
History
• Yeoman first describe
this relationship in
1928
• Robinson first coined
the term piriformis
syndrome in 1947
Anatomical Variations
• Numerous anatomical
variations of this
relationship
Causes
• Intrinsic injury – to the
muscle itself
• Extrinsic injury –
compression at the
pelvic outlet
Causes
• A combination of weaker abductors and relatively stronger
adductors can also cause piriformis syndrome.
• Problems related to sacroiliac joints such as stiffness, overstress
etc. can also lead to this condition as the stress/stiffness is taken
care by surrounding gluteal and piriformis muscles.
• A rotational movement of foot occurs at the subtalar and
talocalcaneonavicular joints, which is known as pronation. If this
movement is overdone, it can cause the knee to turn medially
more than the natural degree of rotation, this is prevented with
the help of piriformis muscles. As the piriformis muscles are not
made to bear such a high stress/pressure, it can lead to
development of piriformis syndrome.
Causes
•
Overstress and strain on the sciatic nerve by piriformis muscle is the main cause
of this syndrome.
• Trauma, any type of injury or stress in the area surrounding piriformis muscles or
disorders related to nerves and muscles, which cause overstress/strain on
the piriformis muscles can lead to development of this syndrome.
•
Inactivation of gluteal muscles that play an important role in helping and
supporting hip extension and piriformis muscles in external rotation of the
femur caused by overstressed and overactive hip flexors; is also considered
to lead to onset of this syndrome.
•
People involved in exercise, sports (race, cycling etc.) and activities that need to
use forward postures/movements of body are prone to develop piriformis
syndrome as a result of the stress and strain on the piriformis muscles. In
order to compensate the stress and strain caused by the forward
movement, one should use stretching and some other exercises so that
piriformis muscles can be relaxed and strengthened.
Controversial Diagnosis
• No consensus among
clinicians on the
validity of this entity
and no documentation
of its incidence
Epidemiologic Considerations
• Piriformis syndrome occurs most frequently during the
fourth and fifth decades of life and affects individuals of all
occupations and activity levels.
• Reported incidence rates for piriformis syndrome among
patients with low back pain vary widely, from 5% to 36%.
• Piriformis syndrome is more common in women than men,
possibly because of biomechanics associated with the wider
quadriceps femoris muscle angle (ie, “Q angle”) in the os
coxae (pelvis) of women
Symptoms
• Buttock pain with or
without pain into the
buttock
• Chronic and acute
cases
• Often a hx of minor
trauma such as falling
on the buttock
Symptoms
Symptoms
• Sitting on a hard
surfaces will
exacerbate the
symptoms of pain and
occasional numbness
and paresthesias
without weakness
Activites
• that produce the
motion of hip
adduction and internal
rotation such as cross
country skiing and the
over head serve in
tennis may also
exacerbate the
symptoms
Symptoms
• Because of the relationship of the piriformis
and the lateral pelvic wall, patients may
experience pain with bowel movements and
women may complain of dyspareunia
Functional limitations
• Pain with prolong
sitting on hard surfaces
such as in church pews,
• Pain with activities that
produce hip IR and
adduction
What is wallet sign?
Is your wallet hurting you?
wallet neuritis
What is Pace sign?
Physical exam – Pace Sign
• Contraction of the
piriformis muscle with
resistant to active hip
external rotation and
abduction may
reproduce pain or
asymmetrical weakness
Pace Sign (FAIR Test)
• FAIR (flexion, adduction, and internal rotation) test involves the
recurrence of sciatic symptoms.
• The FAIR test is performed with the patient in a lateral recumbent
position,
with the affected side up, the hip flexed to an angle of 60 degrees,
and the knee flexed to an angle of 60 degrees to 90 degrees.
While stabilizing the hip, the examiner internally rotates and adducts
the hip by applying downward pressure to the knee.
FAIR Test
• Fishman found the FAIR test to have sensitivity and
specificity of 0.881 and 0.832, respectively.
• Alternatively, the FAIR test can be performed with the
patient supine or seated, knee and hip flexed, and hip
medially rotated, while the patient resists examiner
attempts to externally rotate and abduct the hip.
• The FAIR test result is positive if sciatic symptoms are
recreated.
FAIR Test
•
FAIR (flexion, adduction, and internal
rotation) test.
•
performed with the patient in a lateral
recumbent position, with
•
the affected side up, the hip flexed to an
angle of 60 degrees, and
•
the knee flexed to an angle of 60 degrees
to 90 degrees. While stabilizing
•
the hip, the examiner internally rotates
and adducts the hip
•
by applying downward pressure to the
knee.
What is a positive piriformis
sign?
Positive Piriformis Sign
• Contracted piriformis muscle
also causes ipsilateral external
hip rotation.
• When a patient with piriformis
syndrome is relaxed in the
supine position, the ipsilateral
foot is externally rotated (a
feature referred to as a positive
piriformis
sign.
• Active efforts to bring the foot to
midline result in
pain.
What is a positive Frieberg sign?
Physical exam
• Positive Freiberg test –
passive hip abduction
and internal rotation
may compress the
sciatic nerve
reproducing the pain
What is Beatty maneuver?
Beatty Maneuver
• Patient lies on the
uninvolved side and
abducts the involved
thigh upward, which
elicits pain.
• If sciatic symptoms are
recreated, the test
result is positive.
What muscle is functionally
related to the SI joint ?
Short leg and Sacrum Torsion
• In most cases of piriformis
syndrome, the sacrum is
anteriorly rotated toward the
ipsilateral side on a contralateral
oblique axis, resulting in
compensatory rotation of the
lower lumbar vertebrae in the
opposite direction.
• For example, piriformis
syndrome on the right side
would cause a left-on-left
forward sacral torsion with L5
rotated right. Sacral rotation
often creates ipsilateral
physiologic short leg.
Physical exam
• Normal neuro exam (strength and reflexes)
• Tenderness to palpation is experience from
the sacrum to the greater trochanteric
representing an area of the Piriformis Muscle
• Palpable taut band on rectal exam
Differential Diagnosis
Secondary causes:
– Superior and inferior gluteal artery aneurysm
– Benign pelvic tumor
– Endometiosis
– Myositis ossificans
Dx that mimic PM
Lumbar facet syndrome
L5S1 radiculopathy
Diagnostic testing
•
•
•
•
Clinical diagnosis
MRI and CT rule out other disorders
Prolong H wave
EMG to r/o other things
Treatment
• Throughout the physical evaluation of patients,
clinicians should maintain a high index of
suspicion for piriformis syndrome.
• Early conservative treatment is the most
effective treatment,as noted by Fishman who
reported that more than 79% of patients with
piriformis syndrome had symptom reduction
with use of nonsteroidal anti-inflammatory
drugs(NSAIDs), muscle relaxants, ice, and rest.
Treatment
• NSAID
• Heat
• cushions
Treatment
• Stretching of the piriformis muscle and strengthening
of the abductor and adductor muscles should also be
included inpatient treatment plans.
• A manual medicine approach may combine muscle
stretches, spray and stretch technique, and soft
tissue, myofascial, muscle energy, and thrust
techniques to address all somatic dysfunctions in the
patient with piriformis syndrome.
•
Treatment
•
In particular, the strengthening of the adductor muscles
of the hip has been shown to be beneficial for patients
with piriformis syndrome.
•
Several studies have reported that additional benefit
can be derived from physical therapy modalities, such as
heat therapy, cold therapy, BTX-A injection, and ultrasound.
•
Heat or cold therapy is usually most effectively applied before
the physical therapy or home therapy sessions because it may
lessen the discomfort associated with direct treatment applied
to an irritated or tense piriformis muscle.
•
Injections of BTX-A, when used as an adjunct to physical therapy, have
been shown to produce more pain relief than lidocaine with
steroids
Counterstrain Technique
•
Three tender point locations can be
addressed with counterstrain—at the
midpole sacrum, piriformis muscle, and
posteromedial trochanter.
•
To position a patient for counterstrain
treatment, the patient is generally asked
to lie in a prone positionwith the affected
side of the body at the edge of the
examination table.
•
•
In performing the counterstrain
technique, the physician brings the
patient’s affected leg overthe side of the
table, placing it into flexion at the hip
and knee, with abduction and external
rotation at the hip .
Physical Therapy
•
Patients with piriformis syndrome may be treated with physical
therapy involving a variety of motion exercises and stretching techniques.
•
It is important for the physician to clearly demonstrate the stretches that the patient is
expected to perform.
•
It is also advisable to have the patient perform these exercises for the first time in the
office, where the physician can observe and modify the patient’s techniques, as needed.
•
If the patient demonstrates excessive difficulty in understanding or performing the
exercises, the physician can refer the patient to a licensed physical therapist for assistance.
•
If a patient is able to perform the required exercises at home, he or she should be advised
to do so in multiple short sessions each day, with each session lasting only a few minutes.
Stretching
Strengthening
• Gluteus medius –
theraband around the
ankles and walking
sideways
Correct Biomechanic abnormalities
•
•
•
•
•
•
Increase pronation
Hip abductor weakness
Lower lumbar dysfunction
SI hypo mobility
Hamstring tightness
Lead to a gait with hip in ER, shortened leg
length and a functional short leg
Ultrasound and stretch
• Hip IR above 90 degrees of hip flexion
• Hip ER below 90 degrees of hip flexion
Other treatment options
• Injection 1cm caudal and 2cm lateral to the
lower border of the SI joint
• Caudal epidural
• Surgical release
Physiatric Prescription