Friday, March 19, 2010

A Forgotten or Often Overlooked Cause of Lower Back Pain- Iliosacral Nodules


a) Single or multiple fatty nodules along the superior border of the posterior iliac crest 4 to 6 cm from the midline of the back.

b) Posterior branches of the lumbar plexus penetrate the fascia in the same area.

Pain Mechanism

Compression of/or stretching of these neurofibrils as they pass through the fascia or in the subcutaneous area give local or referred pain & tenderness.

Referred pain may be felt locally in the buttock in the lower areas of the abdomen, in the groin, in the testicles or in the anterior & medial aspect of the upper thigh.


1) Local and referred pain initially intermittent becomes progressive in frequency and severity.

2) Increased by posture changes-squatting, recumbency (often on arising in the am), twisting as in golf, tennis or work activity.

3) History of mattress changes

4) History of multiple investigations & specialist referrals.

5) History of multiple forms of therapy non-surgical such as physiotherapy, massage, acupuncture, analgesics, etc.

6) History of inappropriate surgical procedures such as laparoscopes, colonoscopies, groin explorations and even major back operations.

Diagnostic Test

Objective: To avoid delay in diagnosis and inappropriate treatment.

Technique: Injection of a long acting local anaesthetic directly into the tender nodules.


A) If no relief of discomfort look for an alternative cause of pain.

B) If immediate relief of the local and referred pain occurs and lasts for the duration of the anaesthetic or longer, consider this as a positive test. A repeat diagnostic test with a similar dramatic success is an absolute indication to proceed to definitive treatment.

Definitive Treatment- Excising Iliosacral Nodules

A minor operation under local anaesthetic

1) Mark the skin over a 1 ½ “ – 2” where the painful nodules are palpated.

2) Infiltrate with local anaesthesia

3) Incise and deepen incision to the fascia exposing the iliosacral nodules.

4) Remove iliosacral nodules

5) Palpate for fine neurofibrils penetrating the fascia and transect them.

6) Close wounds in two layers once hemostasis is achieved.

7) Compression dressing with betadine or iodine


Over 200 patients highly selected by means of the diagnostic test underwent the surgical procedure to remove iliosacral nodules. 98% experienced full relief. 2% were better.

Contralateral procedures were done later in about 20%.

Ipsilateral recurrent nodules were excised in 5% of patients.


The procedure is fairly simple but one should remain aware of the general risks of surgery. There is a small chance of seroma formation, infection and wound separation. In this study none of the 200 patients contracted an infection.


A large percentage of individuals with chronic low back pain due to a simple treatable cause have been misdiagnosed and/or mistreated. The cost to society is enormous in terms of unnecessary pain and suffering and the resultant financial implications.

In summary therefore by following this simple approach in the diagnosis and treatment of the this common cause of chronic low back pain a great deal of suffering will be eliminated.

The loss of man hours alone may save billions of dollars to our overstretched medial costs world wide.

Dr. Joseph P. McKenna, FRCSC

Toronto, Ontario

March, 2010