It’s a real pain not being able to decipher what exactly the root cause of your gluteal miseries is Although the terms “piriformis syndrome” and “sciatica” are often mentioned by your GP when talking about gluteal pain or upon googling your symptoms, you seem to still be unsure of which diagnosis to stick with and how to go about treating it. It is time to negate the middleman of all the guesswork and uncertainty and through this article, understand the working of these two distinct conditions.

Both issues can be easily diagnosed and present with numerous options for treatment and exercises in order to heal appropriately. When misdiagnosed and/or mistreated, these conditions can become more exacerbated and last longer than they actually would have to. The similarities between piriformis syndrome and sciatica are limited to the area of pain, which includes the buttocks and legs, due to compression of the sciatic nerve. This article delves deep into and will provide you with a comprehensive review of piriformis and sciatica, focusing on the clinical presentation, diagnostic criteria, treatment and management strategies.
Figure 1: Image of a man holding a skeletal structure of the pelvis around where it would be located in the body in order to demonstrate how it would be anatomically placed. (Pixabay, 2023)

Introduction

Some of the hallmarks of the condition is both being one-sided, with a prolonged pain in the hips or buttocks that tends to radiate down to one’s legs. Both are caused due to interference in the sciatic nerve function, which is the largest nerve in the body, starting in the lower back and going down all the way along the lower limb to the heel of the foot.² Piriformis syndrome is usually a result of a specific muscle in your gluteal region, known as the piriformis muscle, compressing the sciatic nerve. Sciatica, on the other hand, results from some sort of spinal dysfunction due to the compression of nerve roots present in the lumbar spine that tends to lead to sciatic nerve dysfunction.¹

Figure 2: Illustration of piriformis and sciatic nerve stock illustration⁶

What is piriformis syndrome?

The piriformis is a relatively small, pyramid-shaped muscle that is located quite deep in the gluteal region, more visible from the back of the pelvis. The muscle attaches to the greater trochanter of the femur in the thigh, originating in the sacrum - lower backbone - in the body. The sciatic nerve passes underneath the piriformis or at times through the muscle in about 15-20% of individuals. 

Figure 3: Piriformis syndrome usually occurs when the piriformis muscle in the gluteal region tends to spasm and lead to buttock pain. Similarly as in sciatic pain, at times the muscle can also aggravate the sciatic nerve that passes through it, due to excess compression, leading to sensations of tingling and numbness as well as causing pain along the back of the foot and leg.⁷

The piriformis muscle present in the pelvis is required for numerous functions of our legs and hip, some of which are to:

• Stabilise the sacroiliac joint during weight-bearing activities.
• Externally rotate the hip:  such as rotation of the thigh bone facing away from the body.
• Abduction of the hip.
• Support the posture and stabilise the body by maintaining proper alignment.
• Increase sports performance.

People who have the sciatic nerve passing through the piriformis muscle tend to be phenotypically predisposed to piriformis syndrome. 

What is sciatica?

In the lumbar spine, around where the sciatic nerve arises, sciatica is caused due to the irritation or compression of the sciatic nerve roots. This usually is caused due to spinal stenosis, degenerative changes within the spine or most commonly an intervertebral herniated disc - also termed a slipped disc⁴

The compression in these nerve roots tends to cause radical pain and a feeling of numbness along the entire length of the sciatic nerve, at times originating from the lower back and going all the way down to the heel of the foot.

Figure 5: Sciatica Pain concept with a woman suffering from buttock pain spreading down the leg.⁹ 

In the case of sciatic nerve pain, it starts above where piriformis syndrome’s pain would begin, at the lumbar vertebrae of the lower back that is present above the piriformis muscle. 

How do the conditions manifest?

Piriformis syndrome

• Radiating pain down the leg
• Gluteal pain
• Pain in opposite sacroiliac joint
• Increase in pain due to activity
• Tender to the touch
• Pain whilst sitting down
• Weakness in the muscles
• Difficulty when walking
• Relief in pain during rest
• Worsening of symptoms at night, particularly when lying on your side

Sciatica

• Radiating pain down the leg
• Gluteal pain
• Lower back pain
• Aggravation of pain during heavy lifting
• Numbness and tingling in the affected leg
• Difficulty when walking
• Relief in pain during rest

Piriformis syndrome vs. sciatica

Apart from having separate points of origin, sciatica can often be much different from the former condition. The piriformis muscle is compressed - at times the sciatic nerve passes through or under the piriformis muscle that also gets compressed -  leading to pain and numbness down the back of the leg starting at the buttock. The exact cause of piriformis is unknown but factors such as muscle spasms or tightness, trauma, or overuse of the muscle could lead to the development of this syndrome. 

Sciatica happens when the sciatic nerve is compressed, pinched, or aggravated as it exits the lumbar vertebrae in the spinal code. Other conditions often  caused by piriformis muscle compression are   spondylolisthesis, disc herniation, or spinal stenosis⁵

It is quite a task to diagnose piriformis syndrome and differentiate it from sciatica since piriformis syndrome causes similar pains such as sciatic pain that compresses the sciatic nerve and is classified as sharp pain that radiates from the lower or mid glutes. 

How is piriformis syndrome diagnosed and differentiated from sciatica?

It is important to rule out the possible overlapping symptoms between the two using differential diagnosis methods. Symptoms such as bursitis, tendonitis, lower back pain, and sacroiliitis should be ruled out as they are similar within both conditions. Along with that, other clinical presentations, such as noticing symptoms of an increase in coughs or sneezing that occur with the increase in intra-abdominal pressure which is a pair of symptoms that pertain to sciatica while symptoms of pain and tingling when aggravated upon climbing, walking, or sitting tend to be more related to piriformis syndrome. 

Visiting your healthcare provider with your concerns is advised. They would check for the patient’s familial history, examination of the patient’s physical symptoms, and conduct diagnostic imaging. Also, the patient’s posture, the alignment of the shoulders and legs, and gait along with any other discrepancies in the leg length would be assessed as these could be causes of excessive stress in the piriformis muscles or the sciatic pain due to irritation in the nerves or muscles around the pelvic or gluteal region nearing the lower back. 

In order to further clarify the condition, an x-ray of the entire spine, with a focus on the lower lumbar region along with the pelvis and hips of the patient can be considered. Once most spinal and/or skeletal issues have been crossed off, there are a multitude of physical examination tests that can be used to furthermore piriformis from other similar sciatic conditions. Specific physical examination manoeuvres, for example, the piriformis stretch test, straight leg raise test, and Frieberg’s manoeuvres can further help distinguish between the two as they all target different muscle groups. 

One of the main tests that is conducted is the Pace test. The patient is seated, resisting moving their leg away from the body. If the patient is afflicted with piriformis, they experience feelings of deep discomfort in their gluteal muscles followed by pain.

Imaging modalities such as Magnetic Resonance Imaging (MRI) Scans can be conducted to visualise and differentiate between spinal dysfunction and lower back issues or inflammation of the piriformis muscle. 

How is this treated?

Just like a few of the symptoms share some similarities between the two conditions, the treatment methods of the two conditions also have some things in common. Mainly include undergoing physiotherapy, focusing on deep tissue or soft tissue massage, ranging from spinal mobilisation to percussive therapy for the affected areas subjected to tension or tightness. Acupuncture, rest, non-steroidal anti-inflammatory drugs (NSAIDs), or corticosteroidal injections can be considered, in cases of persistent pain. 

In extreme cases, surgical intervention could also be considered, such as piriformis muscle release for piriformis syndrome or lumbar discectomy for sciatica.

Overall, it’s important to try to regain strength and mobility within the afflicted regions by employing exercises and stretches followed by adequate rest. Focusing on localised exercises that target the gluteal muscles in the case of piriformis syndrome and neural and back mobility exercises in the case of sciatica will be highly beneficial for the afflicted individual. 

Summary

Piriformis syndrome and sciatica present with certain similar clinical symptoms but have two distinctly differing etiologies and pathophysiologies. Thereby, the patient must be carefully examined, in order to determine the true origin of the pain: whether it is arising from the piriformis muscle present near the gluteal muscles with the sciatic nerve passing through it or if it begins from the lower lumbar vertebrae, respectively. The treatments for these two conditions vary and mistreatment could lead to these easily diagnosable and identifiable conditions becoming more aggravated and harder to treat, requiring more invasive procedures. Ensuring that there is proper gait and length maintained is crucial in order to not excessively tense or compress a particular region of the sciatic nerve.