IN THE FIRST ARTICLE IN THIS SERIES, I discussed the concept (initially described by the French physician Robert Maigne) of thoracolumbar facetal irritation creating symptoms in the posterior pelvis, the lateral thigh and the inguinal region. See Nerve Entrapment (Part One) Lumbo-Pelvic Pain, October 2015 ACA News, Page 26.] Maigne’s work explained that pelvic pain may originate higher in the trunk and arise from the lateral branches of the dorsal ramus. Maigne proposed that manipulation of the T10-L2 vertebral segments may reduce the symptoms associated with thoracolumbar junction syndrome. He uncovered this notion through research, clinical observation and knowledge of anatomy and human dissection. While Maigne identified common pain distribution patterns, I should note that innervation from the lateral branches of the dorsal ramus may vary from person to person.
Superior Cluneal Nerve Entrapment
This article will focus on a peripheral nerve entrapment that may occur downstream from the thoracolumbar junction: superior cluneal nerve entrapment. Strong and Davila were the first to describe this condition in 1957. While the superior cluneal nerve neuropathy has been identified as a source, albeit rare, of lower back and posterior pelvic pain, there has been little research on the effectiveness of treating this condition. The superior cluneal nerve originates from the posterior rami of L1-2-3, then descends inferior to cross over the crest of the ilium in three branches. The medial branch travels through an osteofibrous tunnel, which has been cited as a site of entrapment similar to carpal tunnel syndrome. The osteo component of this tunnel is the rim iliac crest, and the fibrous component is composed of the tough thoracolumbar fascia.
Clinical Presentation of Superior Cluneal Nerve Entrapment
Superior cluneal nerve entrapment will present with pain over the posterior ilium and upper buttocks region. You may also feel a thickening of tissue along the rim of the posterior iliac crest, and there may be tenderness in this region. By tapping on the tender spot or thickened tissue, you may evoke a shock-like sensation. If this tapping produces an electrical shock-like sensation, it is considered a positive Tinel’s sign. This is strongly indicative of cluneal nerve involvement.
Making the diagnosis of a superior cluneal nerve syndrome is easier than treating this disorder. Few inroads have been made in studying the treatment of this malady, so we are left with anecdotal recommendations for treating pain attributed to the superior cluneal nerve entrapment. Medical practitioners may perform pain injection procedures or more rarely a surgical release of the entrapment.
Manual practitioners can utilize manipulation of the segments of innervation for this region (T11-L2), instrument-assisted myofascial mobilization (such as Graston Technique), pin and stretch techniques and soft-tissue mobilization techniques. While there is little evidence to validate manual treatment as being effective in treating this condition, there is no evidence to indicate that it is not effective. Hence a trial treatment of manual methods is still prudent.
I treat superior cluneal nerve syndrome with adjustments and soft-tissue mobilization using a motorized prone distraction table to elongate the fascia as I perform either a pin-and-stretch-type “release” or use a myofascial mobilization instrument. Although I feel that this technique is effective, my assessment is based solely on anecdotal experience. I would be the first to say research is needed to substantiate its effectiveness. While all health care professionals use unsubstantiated treatment methods, we need to avoid making unsubstantiated claims about those treatments.