1962 Duval – Sciatiques et lipomes épi-sacro-iliaques

This is an original French thesis titled Sciatiques et lipomes épi-sacro-iliaques (these lipomas are also known as back mice) published in 1962 by Gérard Duval in the Université de Bordeaux, Faculté Mixte de Médicine et de Pharmacie.

Sciatiques et lipomes épi-sacro-iliaques

He presents a bibliographical review about the lipomes épi-sacro-iliaques or back mice with references to: Bonduelle & Sallou, 1945; Copeman, 1943; Copeman & Ackerman, 1944; Copeman & Ackerman, 1947; Copeman & Ackerman, 1949; Hittner, 1949; Joyeux, 1955; Katz & Berck, 1950; Monnerot-Dumaine, 1955; Nunziata, 1953; Ries, 1937; Rochegude, 1937; Rouhier, 1951; Sicard & Lord, 1952; and Sutro, 1935.

He presents 3 medical cases and insists that the surgical removal can be a permanent cure with quite good results.

The thesis does NOT present any figure or photo.

It focuses on the lumbosciatalgic syndrome that the lipomes épi-sacro-iliaques can cause. Warning that the patients present as middle-aged menopausal women with “rebel sciaticas” that have certain characteristic presentation.

He related the sciatic pain to the affection of the posterior peripheral lumbosacral nerves.

Sciatiques et lipomes épi-sacro-iliaques

Thèse pour le Doctorat en Médecine

Thesis from Gérard Duval

Introduction from Gérard Duval of the thesis Sciatiques et lipomes épi-sacro-iliaques

They decided to do a thesis after having the experience of 3 cases of lumbosciatica related to a lipoma at the level of the sacroiliac joint.

The relatively low frequency of this entity is mainly due to the fact that it was poorly understood until about the last 10 years, when more studies have been done (see references).

Professor Sicard showed its importance in an article in 1952.

Duval mentions that lately there are many cases of disc hernia with “lombo-sciatiques rebelles” and that maybe surgeons will have to take more in consideration the possibility that these lipomes can cause sciatica.

The first observation about the painful sacroiliac lipoma dates back to 1937, Ries exposed his work to the Chicago Gynecological Society.

Copeman and Hittner attempted to build an etiopathogenic explanation based on the concept that the fat cells were confined in a too narrow capsule and underwent certain type of edema.

In France, Rochegude was concerned with the nervous disorders involving the patients with cases of symmetrical lipomatosis.

Florentin and Louyot published about inflammatory and necrotic formations during progressive rheumatic diseases and in some of the lipomas.

In 1951, Rouhier made a communication to the academy of SURGERY on the “Painful lipomas of the sacral region”.

In 1952, M. Bonduelle and C. Sallou published their experiences with episacro-iliac lipomas based in 11 cases. They insisted on the importance of novocaine infiltrations not just for diagnostic purposes but also as a treatment technique for sciatica.

In 1955, M.R. Joyeux reports a case of a lipoma having led to lumbosciatica and proposes a pathogenic theory based on a vasomotor phenomenon that causes the turgidity of the lipomatose masses and the compression of the intra-nodular nerve fibers.

The term “episacroiliac” comes from the fact that these lipomas are always deep in contact with the fibrous formations of the sacroiliac joint, but they remain free in the cellular tissue.

Duval’s 3 observations related to Sciatiques et lipomes épi-sacro-iliaques

Sciatiques et lipomes épi-sacro-iliaques 

CASE 1. A 48-year-old woman. Visited by D. Laffaille in June 1957. A brutal pain in the lower LEFT limb in a sciatic distribution to the posterior side of the thigh and the popliteal fossa started without prodome. It did not reach the foot. Pain got worse standing and in supine position. The only position she could stand was sitting on the edge of the bed, using cushions.

Examination: No dysesthesias. Antialgic position. No kyphosis. No pain at the L5 level of spinous apophysis. Limitation of spine movement because of pain. Hyperextension very painful. Slight flexion is possible. The patient could still do her housework. No Lasègue sign. Lateral inclination limited on the healthy side. No Bonnet sign. Valleix points are painful. No alteration of sensitivity and reflexes. On the sacroiliac region they palpated a deep elastic ROLLING UNDER THE FINGER the size of the walnut a mass. The pressure on it elicited pain to the suffering side.

The anesthetic test into the lipoma stopped the pain for several days; the effect was longer than it would be expected from a local anesthetic. After the test the patient decided herself to perform a surgical removal of the lipoma.

The X-rays showed signs of discopathy on left L4-L5. So it could explain the sciatic pains.

In July they performed a surgical removal under local anesthesia: Vertical incision in the sacroiliac region. Remission of the pain during the same day of the operation. Small hematoma.


Case 2. A 58-year-old woman. Cousin of case 1. Visited in May 1960 by Dr. Laffaille. The pain started in 1954 while she was in Brazil with sudden brutal acute pain in the LEFT inferior abdomen, the lumbar region and radiation to the LEG all the way to the foot. No dysaesthesia but cramps. The patient had to rest at night with her feet hanging and her hips and knees bent. The treatment she received in Brazil was a combination of B vitamins. The pain got a bit less, but she presented new episodes that were treated with massage, back elongations and infiltrations.

She returned to France in 1955, and then she presented a new crisis of more intensity. Then she learned about the case of her cousin.

Inspection: antialgic attitude. Movements: lumbar stiffness, hyperextension painful and limited.

A slight sign of Lasègue and pain in the Valleix points. No sensory or reflexes disturbances.

Palpation revealed a bilobed mass of the volume of a chestnut, mobile rolling under the finger, around the sacroiliac area. Pressure of this mass was very sensitive and awakened the pain radiating towards the buttock and the thigh. They did NOT have X-ray for that case.

They performed an anesthetic test. The symptoms disappeared for 2 days, then the pain returned with certain improvement and finally it reappeared. Then they decided to operate her.

Local anesthesia. They excided a BILOBULED lipoma lying in deep planes. Hematoma that needed evacuation. The patient was free from pain 10 days after.

Case 3. A 34-year-old woman. Visited in May 1962 by Professeur Pouyanne. Pain started years before with low back pain and left sciatica that required the patient to stay in bed for a month. The pain still persisted despite several treatments: 12 sessions of elongations (with some aggravation). In November 1962 she presented a right-sided crisis of pain with long lasting paresthesias and cramps. The pain was worse at coughing. Currently she presented a LEFT lumbosciatalgic pain. She practiced sport before the pain. Palpation sensitive in region L5 and S1. No Lasègue sign. Abolition of right Achilles reflex and certain hypoesthesia. On palpation of the episacroiliac region, there was a small painful lipoma, the size of a walnut. Its pressure woke up the pain. R-ray did not show pathological signs. By the time of the publication of this thesis the patient still had not gone under surgery.

Duval’s notes about etiopathogeny of the Sciatiques et lipomes épi-sacro-iliaques

The frequency of these lipomas is still rather difficult to determine in patients with lumbosciatalgia. They seem to be more common in the 40s and in women (Duval mentions Fiessinger’s theories relating the lipomas to a lipid metabolic disorder at the time of the menopause).

Duval is aware that the lipomas are NOT related to the sciatic nerve in any of its path.

Duval mentions theories about:

-Copeman and Ackerman (edema)

-M. R. Joyeux (edema by cause vaso-motor)

-Florentin et Louyot (related to nodule d’Aschoff)

-Bonduelle et Salou (related to articular problems).

Duval related the sciatic pain to the affection of the “PLEXUS SACRÉ POSTÉRIEUR”. There are 5 sensitive filaments.

Rüdenger studied them, the nerves are born from the first three posterior sacred branches at their exit from the sacred holes. The irritation of these sacral nerves can provoke the “sciatic-like” pain.

The injections with novocaine 1% stop the pain in a prolonged way, becoming a therapeutic and diagnostic technique.

These greasy nodules cover the sacro-iliac joint. They are common, and variable in number. They can be unilateral, but more often they are bilateral. From 383 cases Duval says that 276 were bilateral and 107 unilateral (72% bilateral). Size varies from a hazelnut to a mandarin.

THEY ARE ENVELOPED in a capsule.

The histological study described the nodules as benign lipomas, a mass of adipose tissue separated by connective tissue. Sometimes it presented nervous filaments.

Duval’s notes about clinical syndrome related to Sciatiques et lipomes épi-sacro-iliaques

-The pain can appear progressive or acute.

-The pain usually predominates in one side.

-It can radiate to the leg, but usually not further than the knee.

-Pain is mainly tolerable, but sometimes it determines total incapacity.

-The pain gets worse by long standing, efforts, sitting position. It does not improve by resting, contrary to ordinary sciatica.

-Inspection usually shows a typical antialgic attitude with some inflexion.

-Movements: slightly flexion is possible, hyperextension is very painful. The lateral flexions are also limited.

-No pain on palpation of the lumbo-sacral spacing or the spinous processes.

-Percussion: slight pain over L5.

-Lasègue sign is absent.

-Bonnet sign can be present. (Pririformis)

-The Valleix’s points meet along the sciatic nerve.

-Sensitivity and reflexes are most often normal.

-Palpation of the sacroiliac joint reveals one or more DEEP oblique NODULES, elastic, rolling under the finger. Better noticeable in ventral decubitus.

Sciatiques et lipomes épi-sacro-iliaques

-Some of the nodules are tender on palpation, especially when rolling under the finger; pressure REAWAKENS the usual pain referred by the patient (According to A. Sicard and Lord, this is a essential sign for the diagnosis).

The anesthetic test of the cases of Sciatiques et lipomes épi-sacro-iliaques

-It consists of injecting 1% novocaine into the lipoma (Copeman was the precursor of this technique).

-The anesthesia of the lipoma stops the pain for several days, unlike one should expect from the anesthetic temporary effect.

-This technique proves that the lipoma is the origin of the painful syndrome.

The evolution and prognosis of the Sciatiques et lipomes épi-sacro-iliaques

-These sciaticas are characterized by rebellious evolution; they are usually resistant to usual therapies. The pain is tenacious. They may respond to radiotherapy or vitamin B therapy, but just for a short time.

-Elongations and massage give no improvement.

-The prognosis is quite benign but the constant painful syndrome sometimes affects the life of the patient, who usually turns to many specialists in search for a solution.

-It is usually a syndrome of women around 45 years: usually lumbosacralgia bilateral or lumbosciatalgia (pain usually does not reach the foot). Hyperextension is very painful. Lasègue negative. Sensitivity and reflexes normal.

About differential diagnosis: vertebral affections, discopathy (the Lasègue sign), traumatic lesions, spina bifida, sacralization, tumors, and absces.

Treatment of Sciatiques et lipomes épi-sacro-iliaques

Duval says the treatment is simple. It consists of removing the lipoma.

Copeman suggested that the treatment could be done by a dehydration technique to regress the INTERCAPSULAR EDEMA.

It is also not clear how the novocaine injection functions: is it because it breaks the capsule (as Copeman suggested) or it breaks the pain arc reflex?

Bonduelle and Salou noticed that after three or four injections they got good results. Only 2/11 cases resisted the multiple injection technique.

-The surgical technique: The ablation is very easy, since the lipoma is very easily etched out. Care must be taken to remove it completely to avoid any risk of recurrence. If there are multiple lipomas, it is better to remove them all.

-They did not have any relapse.

-Duval’s results: 70 cases: 60 healings, 8 failures, and 2 improvements (86% of cure).

Conclusions about Sciatiques et lipomes épi-sacro-iliaques

-About lipomes épisacro-iliaques and the sciatiques.

-They are more often in women around the menopause.

-The pathogenesis is still unknown.

-They can produce sciatic pain; it can be reproduced by pressing the lipomas.

-Novocaine 1% test can be diagnostic and therapeutic.

-Prognosis is benign despite the pain.

-Diagnostic is easy if one keeps it on mind.

-Definite treatment can be done by surgical removal (easy technique)


Published in August 2018  by Marta Cañis Parera   ORCID iD icon


Bonduelle & Sallou, 1945; Copeman, 1943; Copeman & Ackerman, 1944; Copeman & Ackerman, 1947; Copeman & Ackerman, 1949; Hittner, 1949; Joyeux, 1955; Katz & Berck, 1950; Monnerot-Dumaine, 1955; Nunziata, 1953; Ries, 1937; Rochegude, 1937; Rouhier, 1951; Sicard & Lord, 1952; and Sutro, 1935.