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71 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2019, 3 (1): 71-74

ProsPective and semiexPrimental

The Piriformis Syndrome: Evaluation of Seven Cases
Farhad Mustafa Mousa*, Zainab Aziz Bakr

Department of Physiotherapy, Cihan University-Erbil, Kurdistan Region, Iraq

ABSTRACT

Low back pain is one of the causes of Piriformis syndrome. Low back pain is the second most common medical complaints encountered 
by physicians. More than 50% of the population will complain of low back pain at the same time. Piriformis syndrome may constitute up 
to 5% of cases of low back pain, buttock pain, and lower limb pain. This is a prospective and case–control study. In this study, we study 
268 cases with low back pain; in 268 cases, seven cases had Piriformis syndrome. We studied pain, severity pain, radicular pain, limping, 
and painful sitting. Evaluation of musculoskeletal, BMI, and physical examination of Piriformis sign, Freiberg sign, and pace sign. 
Neurological evaluation was taken by paraclinical examination elevated through X-ray, computed tomography scan, magnetic resonance 
imaging, and electromyography. Data show as mean±SD and we used SSPS software for analysis. In 268 cases with conservative method, 
100% of cases were cure treatment after 4 months, in contrast to surgery methods after 1 month. The result illustrated the significantly 
improved between two methods of treatment (P < 0.0025). In seven cases, four cases had a history of blunt trauma and one case had a 
history of surgery that after 6 months had complication of surgery and scare tissue that with the second surgery release of scare was done 
with 100% cure. Anomaly of Piriformis muscle was seen in one case that surgery was done. Tumor was seen in one case that had pressure 
effect on sciatic nerve that surgery was done. Heterotopic ossification was seen in two cases. BMI of all cases was in normal range. All 
cases with diagnosis of disc herniation were excluded from the study. They were need to surgical operation for herniated disc. Piriformis 
syndrome is differentiated primary from secondary type, in which it is done according to history and physical examination. According to 
the etiology of Piriformis syndrome, the treatments are different. If you see mass that compressed the sciatic nerve, you must remove it. 
If the patient had sacroiliitis, it must be treated in early phase. Surgery of Piriformis is not accepted by all surgeons. It is limited to release 
Piriformis tendon and insertion to femur.

Keywords: Piriformis syndrome, low back pain, buttock pain

INTRODUCTION

Low back pain is the second most common medical complaints encountered by physicians. More than 50% of the population will complain of low back pain at same 
time. Most of us, at 1 time or more, have experienced of low 
back pain. One of the most differential diagnoses of back 
pain is sciatica pain and Piriformis syndrome is one causes of 
differential diagnosis to sciatica pain. The Piriformis muscle 
is a pear-shaped muscle in the buttocks.[1-3] The Piriformis 
muscle has origins from several anatomical locations including 
the anterior surface of the lateral process of the sacrum, the 
spinal region of the gluteal muscles, and the superior/gluteal 
surface of the ilium near the margin of the greater sciatic 
notch. The muscle passes through the greater sciatic notch and 
inserts on the greater trochanter of the femur. It is one of the 
six muscles in the hip short external rotator group, coursing 
parallel to the posterior margin of the gluteus medius.[4,5] 
Piriformis syndrome is an uncommon cause of buttock and leg 
pain. Piriformis syndrome may constitute up to 5% of cases 
of low back, buttock, and leg pain. Piriformis syndrome is an 
often misdiagnosed cause of sciatica, leg or buttock pain, and 
disability. Dysfunction of the Piriformis muscle can cause signs 

and symptoms of pain in the sciatic nerve distribution, that is, 
in the gluteal area, posterior thigh, posterior leg, and lateral 
aspect of the foot. The sciatic nerve may be compressed within 
the buttock by the Piriformis muscle, with pain increased by 
muscular contraction, palpation, or prolonged sitting.[6-8] 
It is often not included in the differential diagnosis of back, 
buttock, and leg pain. In addition, it has received minimal 
recognition because it is often seen as a diagnosis of exclusion. 
Pain is increased in prolonged sitting; specific physical findings 
are tenderness in the sciatic notch and buttock pain in flexion, 

Corresponding Author:  
Farhad Mustafa Mousa, Department of Physiotherapy,  
Cihan University, Erbil, Kurdistan Region, Iraq.  
E-mail: Farhadm.atrushi@gmail.com

Received: Apr 20, 2019 
Accepted: Apr 23, 2019 
Published: Jun 30, 2019

DOI: 10.24086/cuesj.v3n1y2019.pp71-74

Copyright © 2019 Farhad Mustafa Mousa, Zainab Aziz Bakr. This is an 
open-access article distributed under the Creative Commons Attribution License.

Cihan University-Erbil Scientific Journal (CUESJ)

https://creativecommons.org/licenses/by-nc-nd/4.0/


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72 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2019, 3 (1): 71-74

adduction, and internal rotation (FADIR) of the hip. An initial 
description was given by Yeoman, in 1928. In 1934, Freiberg 
recognized the signs specific to this syndrome. However, it 
was only in 1947 that Robinson called this clinical entity the 
“Piriformis” or pyramidal syndrome. The Piriformis muscle 
has been said to receive innervation from L5 to S3 ventral 
rami with most sources using S1 and S2 ventral rami as the 
most common innervation this muscle. The most common 
nerve branches to the Piriformis are from the superior gluteal 
nerve and the ventral rami of S1 and S2. More recently, many 
etiologies of sciatic nerve entrapment around the gluteal region 
or the non-discogenic area have been identified, resulting in 
the use of a new term “The Deep Gluteal Syndrome.”[9-11]

Causes

•	 An	injury,	such	as	fall,	a	blow	to	area	or	car	accident
•	 Overuse,	such	as	from	frequent	running,	excessive	exercise,	

or overstretching, trauma to the buttocks or gluteal region 
is the most common cause of Piriformis syndrome

•	 A	 sedentary	 lifestyle,	 especially	 with	 long	 periods	 of	
sitting

•	 Changing	 from	 a	 sedentary	 lifestyle	 to	 more	 frequent	
exercise

•	 Buttock	muscles	wasting	away
•	 Muscle	tension	and	excess	weight	due	to	pregnancy
•	 Skiers,	 truck	 drivers,	 tennis	 players,	 and	 long-distance	

bikers are at high risk
•	 In	 Morton’s	 foot,	 the	 prominent	 head	 of	 the	 second	

metatarsal causes foot instability and a reactive 
contraction of the external rotators of the hip during gait

•	 Spinal	stenosis	can	lead	to	bilateral	Piriformis	tenderness
•	 Anatomic	variations	of	the	divisions	of	the	sciatic	nerve	

above, below, and through the belly of the Piriformis 
muscle may be causative factors.[12]

Piriformis syndrome is a diagnosis of exclusion. Diagnosis 
of	Piriformis	syndrome	is	based	on	a	review	of	the	patient’s	
medical history, a physical examination, and possibly 
diagnostic tests. Piriformis syndrome is often a diagnosis made 
through a process of ruling out other possible conditions that 
may	be	causing	the	patient’s	symptoms	such	as	a	lumbar	disc	
herniation or sacroiliac joint dysfunction. The history and 
physical findings are key elements in differentiating the more 

Figure 3: Pace test: Pain and weakness are present on resisted 
abduction-external rotation of the thigh

AQ1

Figure 4: It is combination of abduction and external rotation test, it 
is positive in all cases

AQ1

Figure 1: Piriformis sign: More external rotation in the same side 
of pain

AQ1

Figure 2: Freiberg sign: Pain occurs with passive internal rotation of 
the extended thigh when the patient is supine

AQ1



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common forms of LBP and Piriformis syndrome. Many patients 
who underwent unsuccessful surgery in the lumbosacral region 
were later found to have Piriformis syndrome. The female-to-
male incidence ratio of Piriformis syndrome is 6:1. In one study 
at a regional hospital, 45 of 750 patients with LBP were found 
to have Piriformis syndrome. Another author estimated that 
the incidence of Piriformis syndrome in patients with sciatica 
is 6%. The function of the Piriformis muscle is to externally 
rotate and abduct the thigh. In Piriformis syndrome, the only 
true-positive sign is tenderness over the gluteal region.[13] 
The pain can be reproduced with maximum elongation of 
the Piriformis muscle in FADIR of the hip. Weakness can be 
observed with resisted external rotation and abduction of the 
hip.

For diagnosing Piriformis syndrome, several authors 
describe the use of the following signs:
1. Lasegue sign: Pain is present in the vicinity of the greater 

sciatic notch during extension of the knee with the hip 
flexed to 90°, tenderness to palpation of the greater sciatic 
notch is noted

2. Freiberg sign: Pain occurs with passive internal rotation of 
the extended thigh when the patient is supine

3. Pace sign: Pain and weakness are present on resisted 
abduction-external rotation of the thigh.

Robinson, who first described the syndrome, stated that 
Piriformis syndrome had six cardinal features:[14]

1. Sausage-shaped mass over the Piriformis muscle
2. Positive Lasegue sign
3. Gluteal atrophy in chronic cases
4. Trauma to the region
5. Pain exacerbated by lifting and relieved by traction on the 

affected extremity
6. Pain in the sacroiliac joint region, gluteal muscles, or 

greater sciatic notch.

Beatty explained two maneuvers to reproduced the pain 
of Piriformis syndrome in the following way:[10]

1. The patient lies with the painful side up and the involved 
leg flexed

2. The knee of the affected side rests on the table. Pain in the 
buttocks is reproduced when the patient lifts the leg and 
knee slightly above the table.

Diagnostic Considerations

•	 Bursitis	or	weaver’s	bottom	(i.e.,	ischiogluteal	bursitis)
•	 Sciatica	caused	by	compression	secondary	 to	a	 fibrotic	

band, hematoma, or aneurysm of the inferior or superior 
gluteal artery

•	 Pelvic	mass,	tumor,	or	endometriosis	(in	women)
•	 Gout
•	 Referred	pain	to	the	buttock	caused	by	pronator	forces	of	

the foot
•	 Spinal	canal	stenosis.

Differential Diagnoses

•	 Hamstring	muscle	injury
•	 Lumbosacral	disc	herniation	injuries
•	 Sacroiliac	joint	injury
•	 Lumbosacral	discogenic	pain	syndrome

•	 Lumbosacral	facet	syndrome
•	 Lumbosacral	spine	sprain-strain	injuries
•	 Lumbosacral	spondylolysis
•	 Lumbosacral	radiculopathy
•	 Lumbosacral	spondylolisthesis.

Imaging Evaluation

Computed tomography (CT) scan and magnetic resonance 
imaging (MRI)

•	 CT	scans	can	be	used	to	identify	spinal	stenosis	or	arthritic	
changes

•	 MRI	findings	can	rule	out	other	causes	of	back	pain,	such	
as a herniated disc, spinal tumor, or abscess

•	 MRI	 may	 demonstrate	 a	 large	 mass	 anterior	 to	 the	
Piriformis muscle

· The Piriformis muscle also can appear enlarged on T1- or 
T2-weighted images.[4]

Electromyography (EMG)

•	 In	Piriformis	syndrome,	abnormal	patterns	are	found	in	
the gluteus maximus and Piriformis muscles

•	 In	 Piriformis	 syndrome,	 EMG	 findings	 in	 the	 gluteus	
minimum, gluteus medius, and tensor fasciae late muscles 
are normal

•	 EMG	can	also	be	performed	to	determine	neurologic	or	
muscular changes

•	 In	 the	 case	 of	 a	 herniated	 disc,	 all	 muscles	 that	 are	
posteriorly and anteriorly innervated should be affected.

With a herniated disc, a significant delay in the Hoffman 
reflex or H-reflex (motor nerve fiber response after activation 
of afferent sensory spindle fibers) in the affected limbs is often 
present during EMG.[12]

METHODS

This is prospective and case–control study. In this study, we 
evaluated patients with low back pain or lower limb pain 
(268 patients). All cases with diagnosis of disc herniation were 
excluding. In 268 cases, seven cases had Piriformis syndrome; 
these seven cases had low back pain and radicular pain with 
mean average of 42 years old (12–67 years old). In the first 
physical examination was done, we studied pain, severity pain, 
radicular pain, limping, and painful sitting which were taken. 
For evaluation of musculoskeletal we used BMI  and physical 
examination of piriformis sign, freiberg sign, pace sign. 
Neurological evaluation was taken. And after that, paraclinical 
examination elevated X-ray, CT-scan, MRI, and EMG. Data 
show as mean±SD and we used SSPS software for analysis.

RESULTS

In Table 1, specifications of all seven cases, with conservative 
method 100% of cases, were cure treatment after 4 months, 
in which in surgery methods after 1 month that is significant 
between two methods of treatment  (P < 0.00025). In seven 
cases, four cases had a history of blunt trauma. One case had 
a history of surgery that after 6 months had complication of 
surgery and scare tissue that with the second surgery release of 
scare was done with 100% cure. Anomaly of Piriformis muscle 
was seen in one case that surgery was done. Heterotopic 



Mousa and Bakr: Piriformis syndrome

74 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2019, 3 (1): 71-74

ossification was seen in two cases. BMI of all cases was in 
normal range.

DISCUSSION

In this study, we evaluated patients with low back pain or 
lower back pain (268 patients). All cases with diagnosis of 
disc herniation were excluded from the study. They are need 
surgical operation for disc herniation. The best and most 
point in Piriformis syndrome are differentiating primary 
from secondary. It is done according to history and physical 
examination.[18]

According to the etiology of Piriformis syndrome, the 
treatments are different. You see mass that compressed the 
sciatic nerve you must remove it. If the patient had sacroiliitis, 
it must be treated in early phase.

The most differential diagnosis of secondary Piriformis 
syndrome is sacroiliitis in patients with buttock pain. In 
general, condition sacroiliitis are without sciatica pain.[7,8] 
However, it may be secondary to tension of Piriformis muscle 
(Hiltz – 1976) about 8.22% of sacroiliitis was seen in all low 
back pain patients. According to this for differentiated, we 
need to injection to this joint.[10]

Surgery of Piriformis is not accepted in all surgeons. It is 
limited to release Piriformis tendon and insertion to femur.[18] 
Surgery itself has complication and morbidity, scar tissue, 
and compressed the sciatic nerve. Surgery must be limited to 
only remove tissue around sciatic notch and inferior border 
of Piriformis muscle that limited space around the nerve. 
The secondary type of Piriformis syndrome was seen more in 
inflammatory process.[15-18] Surgery and release of Piriformis 
muscle decrease and removed pain in sacroiliitis indirectly. 
However, direct treatment of sacroiliitis joint must be done 
with sacroiliitis girder, manipulation, injection physical 
therapy and at the end, surgery of joint and fusion the joint.

REFERENCES
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piriformis syndrome: An updated systematic review of its 
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2. L. M. Fishman and M. P. Schaefer. “The piriformis syndrome is 
underdiagnosed”. Muscle and Nerve, vol. 28, no. 5, pp. 646-649, 
2003.

3. K. Meknas, A. Christensen and O. Johansen. “The internal 

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pp. 375-80, 2003.

4. A. G. Filler, J. Haynes, S. E. Jordan and J. Prager. “Sciatica of 
nondisc origin and piriformis syndrome: Diagnosis by magnetic 
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imaging with outcome study of resulting treatment”. Journal of 
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5. M. R. Foster. “Piriformis syndrome”. Orthopedics, vol. 25, no. 8, 
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6. L. M. Fishman, G. W. Dombi and C. Michaelsen. “Piriformis 
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8. S. K. Han, Y. S. Kim, T. H. Kim and S. H. Kang. “Surgical treatment 
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9. P. M. Barton. “Piriformis syndrome: A rational approach to 
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diagnostic maneuver”. Neurosurgery, vol. 34, pp. 512-514, 1994.

11. R. P. Beauchesne and S. F. Schutzer. “Myositis ossificans of the 
piriformis muscle: An unusual cause of piriformis syndrome. 
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12. J. A. Brown, M. A. Braun and T. C. Namey. “Pyriformis syndrome 
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patient in the sitting position”. Neurosurgery, vol. 23, no. 1, 
pp. 117-119, 1998.

13. Z. Durrani and A. P. Winnie. “Piriformis muscle syndrome: An 
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14. A. H. Freidberg. “Sciatic pain and its relief by operation on muscle 
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15. J. W. Frymoyer. “Back pain and sciatica”. The New England Journal 
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16. J. J. Jankiewicz, W. L. Hennrikus and J. A. Houkom. “The 
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Table 1: Specifications, age, sex, symptom, causes, treatment, and results of seven cases of Piriformis syndrome

Age Sex Symptom Cause Treatment Results

61 Female Hip pain Trauma Conservative After 6 months cure

45 Male Lower limb pain Trauma heterotopic ossification Surgery After 1 month cure

41 Male Hip and lower limb pain Scare of surgery Surgery After 3 months cure

67 Female Numbness and pain in lower limb Trauma heterotopic ossification Conservative After 4 months cure

42 Male Low back pain and hip pain Anomaly of Piriformis muscle Surgery After 2 months cure

52 Male Sciatica Blunt trauma Conservative After 3 months cure

12 Female Sciatica Tumor of gluteal area Surgery After 1 month cure

Author Query???
AQ1:Kindly cite figures 1-4 in the text part