This is a GREAT article by Copeman and Ackerman from 1947. The authors explain that certain pain syndromes related to the entity called back and gluteal fibrositis (also known as back mice) were related to the oedema or herniation of fat lobules. They found that the pain arise from a fibro-fatty tissue and not from the muscles, as it had often been stated.
Notes on the article:
COPEMAN WS and ACKERMAN WL
Oedema or herniations of fat lobules as a cause of lumbar and gluteal fibrositis.
Arch Intern Med (Chic). 1947 Jan; 79(1): 22-35.
They realized a systematic study of the fibrositis of the lumbar and gluteal regions. They found a “pain pattern” of the trigger points or nodules that correlated with a “fat pattern“.
They found that the pain arise from a fibro-fatty tissue and not from the muscles, as it had often been stated.
The biopsy showed that there was an increase in the volume of certain fat lobules by oedema. Sometimes the fat lobules were herniated through a fibrous compartment. They also mentioned that certain types of periarticular fibrositis of the knee might have a similar mechanism.
Fibrositis is a common entity hardly studied
Copeman an Ackerman started this article commenting that fibrositis is a recognized medical entity that constitutes 12% of all the medical cases. Its pathological foundations are slender and based on the theories of Gowers and Stockman.
Only finding in biopsy was oedema
The authors were struck by the high incidence of this disorder amongst young men and made the attempt to remove and examine the palpable nodules they could feel by examination. On the biopsy material they found that the nodules consisted in fibro-fatty tissue that became oedematous. They never found fibrosis despite the name of fibrositis. This oedema could enclose set up pain by tension. They noticed that similar findings had not been previously described because fibro-fatty tissue abnormalities had not received much attention yet.
Nature of the pain
–The pain can be referred. Thanks to the work of Lewis, it is known that in fibrositis the pain can be referred according to a segmental scheme. The palpable focal points of pain are known as “trigger points“, “myalgic spots” or “fibrositic nodules“. Such referred pain may be felt at a considerable distance from its real source. It is well known that if an anesthetic injection is done accurately into the exact spot (not always an easy target) relief can be obtained.
The trigger point appeared in pyrexial illnesses
They mentioned that Copeman had recently published that he observed that the back pain of many pyrexial illnesses (such as influenza) was of the same nature and pattern as mentioned above, and that although the pain ceased with the end of pyrexia, in a proportion of patients the trigger point persisted. It was thought that much later a further infection or trauma could reactivate the condition.
–Definite sites. They insisted these trigger points occurred in definite “sites of election” in lumbar and gluteal regions.
Sites of the painful spots
–Map of the low back trigger points: They mapped the trigger points in 65 fibrositic patients.
Anatomy of the normal back
–They dissected 14 backs. They mention that not much information regarding fascial layers can be found in anatomy textbooks.
–“Fat pattern” occurred even in cachectic cadavers. They mention that there is a superficial fascia that stretches from the neck to the gluteal region. The space between this fascia and the deep fascia is only a potential one, containing little or no fat. However, in certain areas deposits of pinkish fibro-fatty tissue occurs equally constant with deep ones. They called it “the basic fat pattern“. This occurs even with grossly wasted bodies in which most of the body fat elsewhere had disappeared. They observe herniation of such fat through deficiencies of the fascia.
The “basic fat pattern”
The fat pattern is a collection of fibro-fatty tissue that lies superficial in the lumbar region of the edge of the sacrospinalis muscle. There is a similar fat along the sacro-iliac region.
Careful dissection shows that the cutaneous branches of the posterior rami of the last three lumbar nerves pierce the deep fascia along the edge of the sacrospinalis muscle.
Fascial valve. The nerves appeared to cross the fascia through definite foramens and accompanied by blood vessels. There is a small horizontal fold of the deep fascia overhanging each foramen, which would seem to be designed to prevent the protrusion of its contents by acting as a valve on flexion of the back.
They theorized that the disfunction of these valves could lead to herniation. This could be a cause of ACUTE LUMBAGO that occurs as the result of weight lifting in the stooping position.
In the gluteal region there is a more superficial tongue of pinkish fibro-fatty tissue.
They observed small “bubbles” along the fascia edging sacrospinalis muscle that represented weak spots. Firm pressure on these bubbles of the cadaver caused a fat hernia the size of a pea or larger.
Clinical observations related to herniation of fat lobules
They illustrated 11 cases where the cause of pain was the herniation of fat lobules or fatty tissue.
–CASE 1. Foraminal type of hernia. Patient aged 42yrs. From 1928 after appendectomy the patient had almost continuous backache. Worse after exertion, if tired or with febrile period. On examination, a tender spot was found at the border of sacrospinalis muscle 1 inch above iliac crest. An incision was made to exposed deep fascia. A small lobule of reddish fat was found herniating through a nerve foramen and to be continuous with the deep basic fat. The lobule was removed and the foramen was enlarged.
–CASE 2. Nonpedunculated lateral type of hernia. Patient aged 30yrs. The patient had had severe pain in left buttock and back of the thigh for 1 year. Unknown possible cause. The pain was worse while lying in bed. It flared up with an episode of infective hepatitis. On examination, a tender nodule was found in the left buttock. Pressure on this reproduced the pain to the thigh that ran down to ankle. Procaine 10cc of 1% was injected and the “area” was teased with a thick needle. Later, an incision was made and a lobule the size of a pea was removed superficial to the fascia over gluteus maximus.
–CASE 3. Nonpedunculated, lateral type of hernia. Patient aged 49yrs. The patient suffered from left sciatica for 5 months without known cause. Pain was worse after lying down in the damp. On examination there was a tender spot on the left buttock, pressure caused pain down to the ankle. An incision of superficial fascia was made and an oedematous fat lobule under tension bulged into the bound. When grasped with forceps it caused sciatic pain. Lobule was removed and septal walls broke down.
–CASE 4. Deep nonpedunculated type of hernia. Patient aged 32 yrs. The patient had backache every winter for 5 years. On admission, patient had severe pain in right buttock and down to the right calf. Tender nodules were felt in right buttock, pressure on them reproduced the pain to leg. Vertical incision was made to deep fascia that revealed tense fat of the “marble” size. It was removed.
–CASE 5. Nonpedunculated interseptal hernia. Patient aged 38 yrs. Left sciatica for 10 weeks. Sciatica was worse by cold and movement. Pain was down to the heel and left groin. No cause was found. On examination, definitive palpable nodule was founded. On incision a tense fat lobule in deep layer was founded the size of a “small cherry”. The pain was reproduced on its all distribution by grasping the lobule by forceps.
–CASE 6. Pedunculated fat hernia. Patient aged 30 yrs. 16 years of back pain after accident while skiing. Pain worse by infection or cold weather. A tender nodule was palpated just below iliac crest about 10.2 cm from midline. A fatty lobule was found lying superficially to deep fascia on incision. The pedicle was traced downward into the deep layer.
–CASE 7. Nonpedunculated fat hernia. Patient aged 26yrs. Past history of intermittent backache for about 4 years. A tender nodule was palpated on the edge of the right sacrospinalis muscle about 1 inch above iliac crest. Incision revealed “two bubbles” of thin fascial tissue and on incising them a few lobules of fat appeared. A band of thick fibrous tissue from deep fascia appeared to be constricting.
–Case 8. Fat under increased tension, as a result of old hematoma, giving rise to pain. Patient aged 33yrs. The patient complained of “left lumbago” for 2 years. Caused by lifting a heavy weight. A tender palpable nodule was felt towards the midline, opposite the 4rth vertebra. It was the size of a pea. Incision revealed a tense lobule of fat under tension with a brownish fluid suggestive of an old hemorrhage. The cause was not herniation but increased tension in a fat lobule of subcutaneous fat.
–CASE 9. Compression of a fat lobule by deep fascia. Patient aged 33yrs. Past hystory of intermittent backache referred to thigh for the last 3 years. Palpable node was found 2.5 inches from midline and 1.5 inches below the iliac crest. Vertical incision was made. They found “small fingers” of fat from de deep fascia to superficial one. Fat was not removed, but fascia was left gaping.
–CASE 10. Nature of fat lesion uncertain. Patient aged 46yrs. A prisoner of war. Left backache down to thigh. Examination revealed a tender spot over right edge of the sacrum. A vertical incision didn’t reveal any apparent herniation, but superficial fascia fat was teased and patient said he was cured by procedure.
–CASE 11. Fat hernia of the direct nonpedunculated type. Patient aged 39yrs. He had attacks of “lumbago” related to tertian malaria fevers. He had nodules in both iliac crests, two very tender ones. Incision revealed spherical encapsulated “bubble” of tense pinkish fat.
CLINICAL PATHOLOGY: herniation of fat lobules
The result of the biopsies showed that the trigger points or the tender nodules corresponded with herniations or protrusions of oedematous fat lobules through deficiencies in the walls of their fibrous compartments.
The hernias can be classified into three anatomic types: pedunculated, nonpedunculated and foraminal.
Microscopic examination showed that edema as its only abnormality of the fat lobule, although the blood vessels were congested and in some cases their walls appeared to be thickened. In 3 cases there where areas of young cellular fibrous tissue. On the pedunculated cases it shows older fibrous tissues. Due to active military service they couldn’t stain for nerve endings.
They refer that the fat herniations represent an advanced stage of the disease that in a lower degree is so common as to be almost universally experienced, and it is due to temporary increase in the fluid tension. When the anatomic situation is suitable, it produces the protrusion or herniation.
“PANNICULITIS” or periarticular fibrositis of the knee
-They also investigate some cases of fibrositis that occur around the knee joints chiefly in women who are within the menopausal age zone.
-They studied 6 cases of painful fatty deposits. They found fat was divided into small compartments by fibrous septums, each compartment contained a few lobules. From the subcutaneous region to blend with the deep fascia.
-On dividing the walls of these compartments in painful regions fat lobules immediately bulged out suggestion that their tension was abnormal. There was not any example of herniation.
-The fact that 4 patients had permanent relief after the exploration suggested to them that in the case of periarticular fibrositis or “panniculitis” of the menopausal type, oedema could be the causative factor of pain, which would be explained by the variability of the pain, affected by cold or weather variation.
They advocate that there are therapeutic measures other than surgical (which they did with investigation purposes).
–Heat, massage and movement (“the therapeutic tripod” of rheumatic treatment based on empiric knowledge).
-Heat could increase blood supply that could benefit drainage.
-Massage also could “reduce” oedema in early stages or “break the possible adhesions up” by mechanical pressure. The massage then may cause the disappearance of “the fibrous nodules“.
-The muscular movement could be essential by the functioning of the lymphatic system. It is known that the condition is worse while patient is lying in bed or after a night’s rest.
–Injections of procaine hydrochloride. On the one hand it could act in cases of sudden onset of “lumbago”, thought to be by sudden herniation of fat lobule, by relieving the pain, it could lead to resumption of muscular movement which by itself could reduce the protrusion. It could also be that the injection could disrupt the fat nodule by hydrostatic pressure, and relieve the local tension.
-“Teasing”. They have evolved a “teasing” technique with the needle after 10 or 20cc of 1% procaine under the greatest pressure possible. They achieved more lasting results than with the normal technique of injection.
Published 2018 in March 2018 by Marta Cañis Parera
- Copeman W.S and Ackerman WL. Edema or herniations of fat lobules as a cause of lumbar and gluteal fibrositis. Arch Intern Med (Chic). 1947 Jan;79(1):22-35. PubMed PMID: 20283861.
- Gowers WR. A Lecture on Lumbago: Its Lessons and Analogues. Delivered at the National Hospital for the Paralysed and Epileptic. British Medical Journal. 1904;1(2246):117-121.
- Stockman. A Discussion on Fibrositis. Proc R Soc Med. 1913;6(Balneol Climatol Sect):36-9. PubMed PMID: 19976474; PubMed Central PMCID: PMC2006735.