Characteristics of Low Back Pain due to Superior Cluneal Nerve Entrapment Neuropathy

STUDY DESIGN: Retrospective analysis. PURPOSE: The present study aimed to investigate the features of low back pain (LBP) due to superior cluneal nerve (SCN) entrapment neuropathy (SCN-EN) using the Roland Morris Disability Questionnaire (RMDQ), and to analyze the differences between LBP due to SCN-EN and lumbar spinal canal stenosis (LSS). OVERVIEW OF LITERATURE: The SCN is derived from the cutaneous branches of the dorsal rami of T11–L5 and passes through the thoracolumbar fascia. LBP due to SCN-EN is exacerbated by various types of lumbar movement, and its features remain to be fully elucidated, often resulting in the misdiagnosis of lumbar spine disorder. METHODS: The present study included 35 consecutive patients with SCN-EN treated via nerve blocks or surgical release between April 2016 and August 2017 (SCN-EN group; 16 men, 19 women; mean age, 65.5±17.0 years; age range, 19–89 years). During the same period, 33 patients were surgically treated with LSS (LSS group; 19 men, 14 women; mean age, 65.3±12.0 years; age range, 35–84 years). The characteristics of LBP were then compared between patients with SCN-EN and those with LSS using the RMDQ. RESULTS: The duration of disease was significantly longer in the SCN-EN group than in the LSS group (26.0 vs. 16.0 months, p =0.012). Median RMDQ scores were significantly higher in the SCN-EN group (13 points; interquartile range, 8–15 points) than in the LSS group (7 points; interquartile range, 4–9 points; p <0.001). For seven items (question number 1, 8, 11, and 20–23), the ratio of positive responses was higher in the SCN-EN group than in the LSS group. CONCLUSIONS: Patients with SCN-EN exhibit significantly higher RMDQ scores and greater levels of disability due to LBP than patients with LSS. The findings further demonstrate that SCN-EN may affect physical and psychological function.