Superior and Middle Cluneal Nerve Surgery for Chronic Lumbosacral Myofascial Pain Syndrome

Research Objectives: To investigate the potential of cluneal neurectomy with implantation into adjacent muscle to alleviate lumbosacral pain for those failing to improve with conventional low back pain treatments.

Design: We followed the clinical response of patients with disabling, intractable low back pain who reported relief with anesthetic block of one or more superior and/or middle cluneal nerves and subsequent surgical neurectomy of the same as compared to those who did not have surgery during a 3 year period. Outcomes were evaluated by MANOVA.

Setting: Outpatient Physical Medicine and Rehabiliation / Pain Rehabilitation Clinic.

Participants: Subjects were qualified by a 70%+ pain reduction with focal anesthetic block of cluneal nerve(s). 5 individuals subsequently underwent superior or middle cluneal neurectomies; 12 did not. All participants had previously failed to improve with care-as-usual including exercise, rest, medical management, chiropractic and/or physical therapies, epidural steroid injections, para-facet blocks, radiofrequency ablations, SI joint and/or trigger point injections, lumbar laminectomy/microdiscectomy, or lumbar fusion(s) with residual lumbosacral pain warranting long-term opiates. 16 of 17 subjects were on significant opiate therapy (30+ Morphine mg Equivalent) for 5+ years, with one patient on low dose opiate prior to surgery.

Interventions: Five patients proceeded with neurectomy of involved superior (n=4) or middle cluneal nerves (n=1) with implantation into adjacent muscle for those able (n=5 total) as adjunct to usual cares as listed, whereas the remaining 12 continued care as usual without surgery. All continued with ongoing regular evaluations contingent on medication monitoring needs.

Main Outcome Measures: Daily morphine mg equivalent (MME) opioid dose, lumbar range of motion (ROM) by inclinometry, cognitive status per Trails Making Test performance, as well as self-reported sleep hours, Epworth Sleepiness, 0-10 pain level, depression (PHQ9), anxiety (GAD7), suicidality (SBRQ-R), pain disability index (PDI), and daily hours worked.

Results: At 35, 30, 24, 24, and 14 months post-op, respectively, the five surgical care participants demonstrated statistically significant improvement in pain control (p < 0.001), lumbar mobility (p=0.015), and Pain Disability Index (p=0.005) when compared with the nonsurgical participants. Overall MME dose reduction in surgical cohort decreased from 297 to 68 MME (77%) versus a 23% decrease in the non-surgicals. Similar less-significant trends were evident in improved self-reported Epworth Sleepiness and constipation scores. Two of the five surgical care recipients discontinued all opiate use versus none of the non-surgical participants.

Conclusions: Cluneal neurectomy with implantation into adjacent muscle appears helpful for lumbosacral myofascial pain involving the cluneal nerves in this population.

Author(s) Disclosures: No disclosures applicable.