小腿三头肌肌支超选择性神经切断术联合S2神经根部分切断缓解痉挛性马蹄足的应用解剖学研究及初步临床应用

Applied anatomy study and preliminary clinical application of hyper selective neurectomy of triceps branches combined with partial neurotomy of S2 nerve root to relieve spastic equinus foot

目的探讨小腿三头肌肌支超选择性神经切断术(hyper selective neurectomy,HSN)联合S2神经根部分切断缓解痉挛性马蹄足的可行性。方法采用12具成人尸体标本进行解剖学研究,从后路显露S2神经根及其分支,寻找S2神经根汇入坐骨神经的部位,测量其到中线的距离以及到髂后上棘平面的垂直距离,并确认此处的S2神经根是否已经发出盆内脏神经、阴部神经以及股后皮神经的分支。2023年2月—11月,对4例痉挛性马蹄足患者采用比目鱼肌及腓肠肌内、外侧头肌支HSN联合S2神经根汇入坐骨神经分支切断进行治疗。男3例,女1例;年龄5~46岁,中位年龄26岁。病因包括脑外伤2例,脑出血1例,脑瘫1例。病程15~84个月,中位时间40个月。术前小腿三头肌跖屈肌张力改良Ashworth分级(MAC)为3级2例、4级2例;DanielsWorthingham徒手肌力分级(MMT)评定肌力为2级1例、3级1例,2例因肌张力4级而无法准确测量术前肌力;Holden步行功能分级评价下肢功能,4例患者均为2级。术后采用上述分级评价小腿三头肌跖屈肌张力、肌力及下肢功能。结果S2神经根汇入坐骨神经位置至中线的距离为(5.71±0.53)cm,至髂后上棘平面的垂直距离为(6.66±0.86)cm。在汇入坐骨神经前S2神经根已发出盆内脏神经、阴部神经以及股后皮神经的分支。4例患者均顺利完成手术,随访时间4~13个月,中位时间7.5个月。末次随访时,患者肌张力较术前下降2~3级,肌力较术前无下降,Holden步行功能分级提升1~2级,均无下肢感觉减退。结论小腿三头肌肌支HSN联合S2神经根部分切断可缓解痉挛性马蹄足,且不损伤其余骶丛。

Objective To observe the possibility of hyper selective neurectomy(HSN)of triceps branches combined with partial neurotomy of S2 nerve root for relieving spastic equinus foot.Methods Anatomical studies were performed on 12 adult cadaveric specimens.The S2 nerve root and its branches were exposed through the posterior approach.Located the site where S2 joined the sciatic nerve and measured the distance to the median line and the vertical distance to the posterior superior iliac spine plane,and the S2 nerve root here was confirmed to have given off branches of the pelvic splanchnic nerve,the pudendal nerve,and the posterior femoral cutaneous nerve.Between February 2023 and November 2023,4 patients with spastic equinus foot were treated with HSN of muscle branches of soleus,gastrocnemius medial head and lateral head,and cut the branch where S2 joined the sciatic nerve.There were 3 males and 1 female,the age ranged from 5 to 46 years,with a median of 26 years.The causes included traumatic brain injury in 2 cases,cerebral hemorrhage in 1 case,and cerebral palsy in 1 case.The disease duration ranged from 15 to 84 months,with a median of 40 months.The triceps muscle tone measured by modified Ashworth scale(MAC)before operation was grade 3 in 2 cases and grade 4 in 2 cases.The muscle strength measured by Daniels-Worthingham manual muscle test(MMT)was grade 2 in 1 case,grade 3 in 1 case,and 2 cases could not be accurately measured due to grade 4 muscle tone.The Holden walking function grading was used to evaluate lower limb function and all 4 patients were grade 2.After operation,triceps muscle tone,muscle strength,and lower limb function were evaluated by the above grading.Results The distance between the location where S2 joined the sciatic nerve and median line was(5.71±0.53)cm and the vertical distance between the location and posterior superior iliac spine plane was(6.66±0.86)cm.Before joining the sciatic nerve,the S2 nerve root had given off branches of the pelvic splanchnic nerve,the pudendal nerve,and the posterior femoral cutaneous nerve.All the 4 patients successfully completed the operation,and the follow-up time was 4-13 months,with a median of 7.5 months.At last follow-up,the muscle tone of the patients decreased by 2-3 grades when compared with that before operation,and the muscle strength did not decrease when compared with that before operation.Holden walking function grading improved by 1-2 grades,and there was no postoperative hypoesthesia in the lower limbs.Conclusion HSN of triceps branches combined with partial neurotomy of S2 nerve root can relieve spastic equinus foot without damaging other sacral plexus nerves.