Notes from Andrea’s Trescot book about Chapter 51: Superior cluneal nerve entrapment.
“Low back pain is a widespread health complaint both in the United States and globally. It is a complex condition involving various structures such as ligaments, fascia, nerves, muscles, bones, and other tissues in the back. Despite the use of diagnostic imaging and anesthetic block techniques, around 50% of cases do not reveal an apparent cause.
One possible source of chronic low back pain is the entrapment of the superior cluneal nerves (SCN) near the iliac crest. Cluneal neuralgia, resulting from entrapment of the SCN, is more commonly caused by nerve entrapment rather than direct nerve injury during iliac crest harvest. The SCN can become entrapped as they pass through the fascia near the iliac crest. This condition, also known as posterior rami syndrome, thoracolumbar junction syndrome, Maigne syndrome, or dorsal ramus syndrome, is often underdiagnosed but should be considered as a potential cause of chronic low back pain.
Patients with SCN pathology typically present with severe low back pain radiating to the gluteal region. Different sensations can be experienced, such as chronic pain or dysesthesia localized to the sensory distribution of the affected nerve. The pain often begins in the medial region of the iliac crest and radiates to the ipsilateral buttock and posterior thigh. Lumbar radiography, CT scans, and MRI usually do not reveal any other pathology.
Diagnosis of SCN entrapment neuropathy is primarily based on the patient’s history and physical examination, confirmed by a diagnostic injection. The physical examination includes palpation of the iliac crest to reproduce symptoms and identify tender points. Pain may also be elicited with specific movements of the lumbar spine. Diagnostic criteria for SCN entrapment include unilateral low back pain referring to the iliac crest and buttock, a tender point over the posterior iliac crest about 7 cm from the midline, replication of pain with palpation, and relief of symptoms with an injection.
Various injection techniques can be employed for pain relief, including landmark-guided, fluoroscopy-guided, and ultrasound-guided approaches. Acupuncture and electroacupuncture have also been used as treatment modalities. For more persistent pain, neurolytic techniques such as cryoneuroablation, radiofrequency lesioning, and chemical neurolysis can be considered. In some cases, surgery may be necessary, particularly when less invasive procedures fail to alleviate symptoms.”