Obturator internus syndrome: Cause of buttock pain

Article reviewed and approved by Dr. Ibtissama Boukas, physician specializing in family medicine

The perineal pain represent approximately 4 to 5% of consultations in pain centres. These consultations must follow a consultation of different medical specialties such as urology, gynecology or neurology. These must first exclude an organic cause. Perineal pain can also result from different types of neuralgia, just as they can be of muscular or venous origin. In this article, we are going to tell you about the internal obturator syndrome.

What is internal obturator syndrome?

Le internal obturator syndrome designates thereached du internal obturator muscle. It is characterized by perineal pain of muscular origin.

To better understand this syndrome, let's look at the anatomy of the obturator internus muscle.

Obturator internus muscle anatomy

Le internal obturator muscle belongs to the lower limb called pelvic or caudal. It is a triangular muscular body which is located at the level of the dorsal and lateral muscles of the pelvic belt. This belt allows the attachment of the caudal limbs to the spine.

This muscle is one of the 6 pelvic-trochanteric muscles. These are located in depth, on the dorsal side of the coxo-femoral joint. On its internal surface, the internal obturator muscle lines the obturator membrane of the obturator foramen. On the upper edge of it, it forms an orifice known as the " obturator canal ", or " subpubic canal ". It is through this channel that passes the artery known as the “obturator vasculo-nervous pedicle”.

Origin of the obturator internus muscle

The internal obturator muscle has an endopelvic origin. It originates at the level of the endopelvic surface of the pubic bones and is inserted on the internal bony circumference of the ischio-pubic hole (obturated foramen). On its dorsal side it comes from the obturator membrane.

Termination of the obturator internus muscle

The internal obturator muscle has an exopelvic end. Starting from the endopelvic face of the coxal bone, the muscle is reflected until it forms a right angle when the muscle fibers reach the level of the small indentation sciatica. Then, it moves towards the lateral wall of the trochanteric fossa. This fossa is next to the external obturator muscle.

Innervation and vascularization of the internal obturator muscle

This muscle is innervated by the obturator internus nerve. It is a branch of the sacral plexus: a network of nerves from L4, L5 and S1. Those are branches of sciatic nerve which come from the coxo-femoral joint.

As for its vascularization, it is provided by the caudal gluteal artery and vein.

Roles of the obturator internus muscle

This muscle allows these movements:

• external rotation of the hip;
• abduction of the coxo-femoral joint.

When the leg is fixed, it allows the counter-nutation of the pelvis. On the other hand, when the pelvis is fixed, it allows external rotation and abduction of the thigh.

Difference Between Internal Obturator Syndrome and Piriformis Syndrome

Le obturator syndrome internal is often confused with the piriformis syndrome. This corresponds to damage to the piriformis muscle located just above the obturator internus muscle.

To learn more about piriformis syndrome, see the following article.

Both have the same trochanteric sore spot. However, that of the internal obturator muscle is located:

• on the median vertical axis;
• 5 cm below that of the piriformis muscle;
• on a horizontal line from the greater trochanter to the tip of the coccyx.

What are the causes of internal obturator syndrome?

The origin of these muscular pains is generally mixed. In other words, they are due to both muscle contracture and nerve compression triggering a conflict with the hypertonic muscle. The affected nerve can be:

• du sciatic nerve ;
• the posterior cutaneous nerve of the thigh;
• and even, pudendal nerve.

If the cause of the muscle contracture can result from regular or heavy falls on the buttocks. The cause of nerve compression is not always found. But it can be linked to:

• a pubic fracture;
• obturator hernias;
• narrowing of the obturator canal;
• complications from genitourinary surgery.

What are the symptoms of internal obturator syndrome?

Most patients who suffer from obturator syndrome consult for a buttock pain. Indeed, this syndrome is manifested by pain affecting the buttocks and the lower limb. This pain is worse when sitting. It radiates into the inguinal and perineal territory. This is due to the fact that as it travels through the muscular aponeurosis, the pudendal nerve is under stress.

In general, patients consult in particular when:

• the pain is constantly felt after a fall on the buttocks;
• the seated position is less and less tolerated: when driving, in class or at work;
• the pain triggers a slight limp when walking in the event of disc impingement.

How to diagnose internal obturator syndrome?

Le diagnosis of this syndrome is primarily clinical. It consists of assessing muscle pain by:

• exerting pressure on the large sciatic notch: the pain is easier to find when the pressure is exerted on its external part, which is none other than the trochanteric insertion;
• getting into the prone position: the thigh is extended, then in maximum passive internal rotation;
• using the Freiberg maneuver using passive mobilization with pain (no patient involvement);
• using the Pace and Nagle maneuver with active mobilization (with patient participation).

La freiberg maneuver is to lie in a supine position. The physician gradually brings the patient's affected limb into flexion, adduction, and forceful internal rotation to reproduce the pain.

About the Pace and Nagle maneuver, it consists of getting into a sitting position with your legs hanging over the edge of the examination table. The patient spreads his knees against resistance. Then the doctor holds them in bilateral hip abduction.

The diagnosis is only really established when the Lasègue maneuver. This consists of lying on your back (in the supine position). The doctor lifts the affected limb to lead the patient to describe the pain radiating from the back to the foot. This maneuver will highlight the conflict. It can also cause release by trochanteric disinsertion of the internal obturator.

If needed, imaging tests are done to exclude:

• the piriformis syndrome: a scanner tip makes it possible to precisely determine the topography in question;
• bursitis resulting from the passage of the internal obturator muscle which is reflected against the sciatic notch.

What is the treatment for internal obturator syndrome?

The management of the internal obturator syndrome is mainly rehabilitative. This may include physical therapy (physiotherapy) sessions.

Treatment can also be based on:

• local injections of botulinum toxin or corticosteroids;
• the administration of general and local anti-inflammatories;
• surgery in case of nerve compression: it consists of performing an intrapelvic section of the nerve.

In addition to the treatments mentioned above, there are several products and accessories available on the market to relieve pain related to internal obturator syndrome. It should be remembered that these tools generally provide temporary relief, and should be used sparingly. Among the products recommended by our professionals, we have:

• acupressure mat

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• massage gun

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• Foam roller (sport massage roller)

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• Compex

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• jade stone massage roller

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• Orthopedic knee pillow

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

What about natural remedies?

Although they are not supported by solid scientific evidence, several natural products and home remedies are used to treat various body pains, especially for their anti-inflammatory power.

Here is a non-exhaustive list of plants and essential oils that are effective in controlling pain and inflammation:

• Turmeric : Thanks to its antioxidant and anti-inflammatory powers very powerful, turmeric is one of the most used plants in a culinary and therapeutic context. The composition of turmeric is essentially made of essential oils, vitamins (B1, B2, B6, C, E, K) and trace elements. But it is to its composition rich in curcumin and curcuminoids that we owe them and calm skin of this spice.

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• Ginger : In addition to the special flavor it brings to the kitchen and its aphrodisiac properties, ginger is a root well known for its anti-inflammatory powers. THE gingerol gives it its anti-inflammatory action. It is an active component acting on the inflammatory pain related to chronic joint inflammatory diseases, including rheumatoid arthritis, lupus, rheumatic diseases, etc. It has been proven that this active element is also effective in acting on the inflammation linked to arthritis and sciatica. Ginger also has other benefits thanks to its high potassium content and its richness in trace elements (calcium, magnesium, phosphorus, sodium) and vitamins (provitamin and vitamin B9).

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• Omega-3s : Omega-3 are polyunsaturated fatty acids that play a very important role in the functioning of our body. They are provided by food in three natural forms: docosahexaenoic acid (DHA), alpha linolenic acid (ALA) and eicosapentaenoic acid (EPA). Beyond their action on the brain and the cardiovascular system, omega-3s prove very effective against inflammation. Indeed, they have the ability to act on the inflammatory mechanisms in osteoarthritis by slowing down cartilage destruction, thus they reduce the intensity of osteoarthritis pain. Sciatica, being most often linked to an inflammation secondary to a herniated disc, it can also respond to omega-3 provided it is consumed regularly. 

No product found.

• Lemon eucalyptus: Eucalyptus is a plant most often used in the form of herbal tea or essential oil. She would have anti-inflammatory effects which give it the ability to act on the bone and joint pain in general and the pain of sciatica in particular.

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

• wintergreen : Wintergreen is a shrub from which a very interesting essential oil is extracted. It is one of the most used essential oils in aromatherapy. This oil extracted from the shrub bearing the same name, is used in massage to relieve sciatica and act like a analgesic. Indeed, it provides a heating effect thanks to its ability toactivate blood circulation locally.

Last updated on 2024-04-13 / Affiliate links / Images from the Amazon Partners API

References

https://www.lamedecinedusport.com/dossiers/les-sciatiques-tronculaires/

https://www.notrefamille.com/sante/encyclopedie-sante/syndrome-du-nerf-obturateur-9372?fbclid=IwAR0x8s5B3ezpzn1l4DaZUEdrnS_dVFXphBA9B6emRP1rI1xmMKXe_YA6Euc