Abstract
Abstract
Objectives
Low back pain is a prevalent public health issue caused by superior cluneal nerve (SCN) entrapment. This study aimed to explore the course of SCN branches, cross-sectional area (CSA) of the nerves, and effects of ultrasound-guided SCN hydrodissection.
Methods
SCN distance relative to the posterior superior iliac spines was measured and compared with ultrasound findings in asymptomatic volunteers. The CSA of the SCN, pressure-pain threshold, and pain measurements were obtained from asymptomatic controls and patients with SCN entrapment at various time points after hydrodissection (with 1 mL of 50% dextrose, 4 mL of 1% lidocaine, and 5 mL of 1% normal saline) in the short-axis view.
Results
Twenty sides of 10 formalin-fixed cadavers were dissected. The SCN locations on the iliac crest did not differ from the ultrasound findings in 30 asymptomatic volunteers. The average CSA of the SCN across different branches and sites ranged between 4.69–5.67 mm2 and did not vary across different segments/branches or pain statuses. Initial treatment success was observed in 77.7% (n = 28) of 36 patients receiving hydrodissection due to SCN entrapment. A group with initial treatment success experienced symptom recurrence in 25% (n = 7) of cases, and those with recurrent pain had a higher prevalence of scoliosis than those without symptom recurrence.
Conclusions
Ultrasonography effectively localizes SCN branches on the iliac crest, whereby increased nerve CSA is not useful for diagnosis. Most patients benefit from ultrasound-guided dextrose hydrodissection; however, those with scoliosis may experience symptom recurrence and whether structured rehabilitation can reduce recurrence post-injection should be considered as one perspective in future research.
Trial registration ClinicalTrials.gov (NCT04478344). Registered on 20 July 2020, https://clinicaltrials.gov/ct2/show/NCT04478344?cond=Superior+Cluneal+Nerve&cntry=TW&draw=2&rank=1.
Critical relevance statement Ultrasound imaging accurately locates SCN branches on the iliac crest, while enlargement of the CSA is not useful in diagnosing SCN entrapment; however, approximately 80% of SCN entrapment cases respond positively to ultrasound-guided dextrose hydrodissection.
Graphical abstract
Funder
Community and Geriatric Medicine Research Center, National Taiwan University Hospital, Bei-Hu Branch, Taipei, Taiwan
Taiwan Society of Ultrasound in Medicine
Ministry of Science and Technology
Publisher
Springer Science and Business Media LLC
Subject
Radiology, Nuclear Medicine and imaging
Reference32 articles.
1. Wu A, March L, Zheng X et al (2020) Global low back pain prevalence and years lived with disability from 1990 to 2017: estimates from the Global Burden of Disease Study 2017. Ann Transl Med 8:299
2. Kuniya H, Aota Y, Kawai T, Kaneko K, Konno T, Saito T (2014) Prospective study of superior cluneal nerve disorder as a potential cause of low back pain and leg symptoms. J Orthop Surg Res 9:139
3. Karl HW, Helm S, Trescot AM (2022) Superior and middle cluneal nerve entrapment: a cause of low back and radicular pain. Pain Physician 25:E503-e521
4. Ricci V, Özçakar L (2020) Ultrasound imaging for the medial branches of the superior cluneal nerve: optimal visibility at the “fatty tunnel.” Pain Pract 20:338–339
5. Wu WT, Mezian K, Nanka O, Chang KV, Ozcakar L (2022) Ultrasonographic imaging and guided intervention for the superior cluneal nerve: a narrative pictorial review. Pain Physician 25:E657–E667