Medial superior cluneal nerve entrapment neuropathy in military personnel; diagnosis and etiologic factors.

BACKGROUND AND

OBJECTIVES

Pain caused by medial superior cluneal nerve entrapment (MSCNE) is an infrequent cause of unilateral low back pain. There is limited information about this neuropathy in the literature. In this study, the etiologic factors leading to this clinical entity were evaluated and also the clinical and imaging findings were examined.

MATERIAL AND METHOD: The study was conducted in 3 groups. The study group included 25 patients with MSCNE, the hernia group included 25 patients with herniated nucleosus pulposus and the control group included 25 healthy subjects. The initial evaluation included lumbar computerized tomography (CT) and magnetic resonance imaging (MRI) in the study and the hernia groups. The comparisons between these two groups were made by using clinical assessment questionnaires (SF-36 mental and physical health scores and Oswestry scale). Additionally, all three groups were compared by lumbosacral radiographies and low back superficial ultrasonographies. As treatment, 1 ml of prilocaine combined with 1 ml of steroid injection was used in the study group.

RESULTS

In the study group, there was no disc herniation, facet joint problems, spinal stenosis or spondylolisthesis detected by CT or MRI. The SF-36 mental health score before treatment was lower in the study group than in the hernia group. The ultrasonographic examination detected a paravertebral hypoechogenic globular-shaped muscle disorganization associated with lipomatous degeneration exclusively localized to the trigger point in the study group. Both the mean soft tissue and the periiliac band thickness were significantly higher in the study group than in the other two groups. The lumbosacral radiographies did not show any significant difference in either the degree of lumbar spinal lordosis or the intercristal line levels among the three groups.

CONCLUSION

This prospective study depicts the etiologic factors, ultrasonographic features and treatment protocol of MSCNE which is usually an underestimated cause of the low-back pain.

LEVEL OF EVIDENCE: Diagnostic study, Level I-1 (prospective study).