Abstract：
OBJECTIVE: The middle cluneal nerve (MCN) is a pure sensory nerve around the middle buttock. Its entrapment between the iliac crest and the long posterior sacroiliac ligament elicits low back pain (LBP) that can be treated by MCN neurolysis or neurectomy. Because few studies examined the pathology of MCN entrapment (MCN-E) we subjected 7 neurectomized specimens from 6 LBP patients to pathologic study.
METHODS: We present 6 consecutive patients (7 sides) with intractable LBP who underwent successful MCN neurectomy. Their symptom duration ranged from 6 to 96 months (average 47.3 months); the follow-up period ranged from 6 to 17 months (average 11.7 months). The surgical outcomes were evaluated using the numerical rating scale (NRS) for LBP and the Roland-Morris Disability Questionnaire (RDQ) score. The resected MCNs underwent neuropathological analysis.
RESULTS: Postoperatively, all 6 patients reported immediate LBP amelioration; their NRS and RDQ scores were improved significantly. Pathological study of the 7 resected nerves showed that the myelinated fiber density was decreased in 6 nerves; we observed marked enlargement (n = 5), perineurial thickening and disruption (n = 6), intrafascicular fibrous changes (n = 5), myelinated fibers separated by fibrous cells under the perineurium (n = 4), and Renaut bodies (n = 3). The 7th nerve appeared normal with respect to the density and size of the myelinated fibers, however, the perineurium was slightly thickened.
CONCLUSIONS: We present pathological evidence at the MCN compression site of 7 nerves from 6 patients whose LBP was alleviated by MCN neurectomy, indicating that MCN entrapment can elicit LBP.
METHODS: We present 6 consecutive patients (7 sides) with intractable LBP who underwent successful MCN neurectomy. Their symptom duration ranged from 6 to 96 months (average 47.3 months); the follow-up period ranged from 6 to 17 months (average 11.7 months). The surgical outcomes were evaluated using the numerical rating scale (NRS) for LBP and the Roland-Morris Disability Questionnaire (RDQ) score. The resected MCNs underwent neuropathological analysis.
RESULTS: Postoperatively, all 6 patients reported immediate LBP amelioration; their NRS and RDQ scores were improved significantly. Pathological study of the 7 resected nerves showed that the myelinated fiber density was decreased in 6 nerves; we observed marked enlargement (n = 5), perineurial thickening and disruption (n = 6), intrafascicular fibrous changes (n = 5), myelinated fibers separated by fibrous cells under the perineurium (n = 4), and Renaut bodies (n = 3). The 7th nerve appeared normal with respect to the density and size of the myelinated fibers, however, the perineurium was slightly thickened.
CONCLUSIONS: We present pathological evidence at the MCN compression site of 7 nerves from 6 patients whose LBP was alleviated by MCN neurectomy, indicating that MCN entrapment can elicit LBP.
摘要：
目的：中臀神经（MCN）是围绕中臀部的纯感觉神经。它夹在髂骨和后长骶髂韧带之间会引起下腰痛（LBP），可通过MCN神经溶解或神经切除术治疗。由于很少有研究检查MCN截留（MCN-E）的病理学，因此我们对6例LBP患者的7例神经切除标本进行了病理学研究。
方法：我们介绍了连续6例（7侧）难治性LBP患者，他们成功进行了MCN神经切除术。症状持续时间6~96个月,平均47.3个月;随访时间6~17个月,平均11.7个月。采用LBP数值评定量表(NRS)和Roland-Morris残疾问卷(RDQ)评分评价手术结果。切除的MCNs进行神经病理学分析。
结果：术后，所有6例患者均报告LBP立即改善;他们的NRS和RDQ评分均显著改善.对切除的7条神经的病理研究表明，6条神经的有髓纤维密度降低；我们观察到明显的扩大（n=5），神经周增厚和破裂（n=6），束内纤维变化（n=5），神经周围下由纤维细胞分离的有髓纤维（n=4），和再生机构（n=3）。第7神经的有髓纤维的密度和大小表现正常，然而,会阴膜略微增厚。
结论：我们在6例通过MCN神经切除术减轻LBP的患者的7条神经的MCN压迫部位提供了病理证据，表明MCN截留可引起LBP。
方法：我们介绍了连续6例（7侧）难治性LBP患者，他们成功进行了MCN神经切除术。症状持续时间6~96个月,平均47.3个月;随访时间6~17个月,平均11.7个月。采用LBP数值评定量表(NRS)和Roland-Morris残疾问卷(RDQ)评分评价手术结果。切除的MCNs进行神经病理学分析。
结果：术后，所有6例患者均报告LBP立即改善;他们的NRS和RDQ评分均显著改善.对切除的7条神经的病理研究表明，6条神经的有髓纤维密度降低；我们观察到明显的扩大（n=5），神经周增厚和破裂（n=6），束内纤维变化（n=5），神经周围下由纤维细胞分离的有髓纤维（n=4），和再生机构（n=3）。第7神经的有髓纤维的密度和大小表现正常，然而,会阴膜略微增厚。
结论：我们在6例通过MCN神经切除术减轻LBP的患者的7条神经的MCN压迫部位提供了病理证据，表明MCN截留可引起LBP。
