A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve a case report

A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve on both sides was observed during the dissection of a 72 year-old female cadaver. The long thoracic nerve included only the fibers from C5 and C6 on the left side. The musculocutaneous nerve was absent and two branches from the lateral cord innervated the coracobrachialis muscle. The median nerve innervated the biceps brachii and brachialis muscles in the arm and also gave off the lateral antebrachial cutaneous nerve. Additionally, a communicating branch was found from the median nerve to the ulnar nerve in the forearm. The knowledge of the anatomical variations of the peripheral nerve system can help give explanation when encountering an incomprehensible clinical sign.     

肱二头肌和三角肌肌支在臂丛的定位及其临床意义

目的：研究肱二头肌和三角肌肌支在臂丛中的定位。方法：通过对１０具尸体双侧肱二头肌及三角肌肌支的解剖，观察其纤维定位，并测定其截面积。结果：在腋部肱二头肌和三角肌肌支分别位于相应神经的外侧份，其截面积分别占主干截面积的３４％和５３％。在锁骨上，肱二头肌肌支位于上干前股的前正中和前外侧份，其截面积占上干前股的３４％，三角肌肌支位于上干后股的后正中和后外侧份，其截面积占上干后股的３７％。结论：在神经移植或移位手术中，应尽可能将动力神经缝接至肌支相应的神经束上，以提高疗效。     

The communicating branch of the 4th cervical nerve to the brachial plexus: the double constitution, anterior and posterior, of its fibers

Twenty-four adult cadavers (48 sides) were used to investigate the incidence of a branch arising from the ventral ramus of the fourth cervical nerve (C4) with the phrenic nerve and subsequently joining the brachial plexus. Six brachial plexuses with spinal cords and phrenic nerves were dissected under a surgical microscope to investigate localization of fibers contained in the C4 branch to the brachial plexus. The incidence of the C4 branch was 23% (11/48 sides). Branches from C4 to the brachial plexus divided into anterior and posterior divisions on four sides (4/6 sides). On two sides, the branch did not divide but consisted entirely of an anterior division (2/6 sides). In the brachial plexus, anterior division fibers of the C4 branch were intertwined with fibers from the anterior divisions of the ventral rami of the fifth and sixth cervical nerves. They then passed to the suprascapular nerve and the anterior division of the superior trunk (6/6 sides). On the other hand, posterior division fibers of the C4 branch were intertwined with fibers from the posterior divisions of the ventral rami of the fifth and sixth cervical nerves. They then passed to the suprascapular nerve (2/6 sides) and the posterior division of the superior trunk (4/6 sides). The anterior division of the C4 branch received fibers from the ventral rootlets of the entire fourth cervical segment, whereas the posterior division received fibers from the ventral rootlets of the caudal half of the fourth cervical segment only. The fact that the suprascapular nerve received fibers from both the anterior and posterior divisions of the C4 branch was considered to support our claim that the human suprascapular nerve belongs to both the anterior and posterior divisions of the brachial plexus.     

臂丛神经的应用解剖

目的通过对臂丛神经的解剖学大体观察和测量,为临床骨科医生对臂丛神经损伤的手术治疗提供解剖学数据,并为解剖学积累新资料。方法对40具国人尸体标本(26具,女14具),80侧臂丛神经,进行研究。首先对标本进行大体观察,描述其解剖学形态,进行分型、分类及内、外、后束合成部位与第一肋外缘的关系;用相关的测量工具(电子游标卡尺)测量上、中、下三干前、后股的比例及根干束的长度并进行统计学分析。结果根干束的长度,C5根:男(33.85±7.07)mm,女(30.30±5.25)mm,C7根和中干:男(52.46±10.55)mm,女(44.15±6.68)mm;C8根:男(25.55±5.88)mm,女(19.91±5.09)mm;T1根:男(23.81±5.58)mm,女(19.16±4.02)mm;上干:男(24.69±9.91)mm,女(18.86±4.93)mm,下干:男(33.13±9.21)mm,女(25.44±9.41)mm;后束:男(31.21±13.93)mm,女(37.36±9.93)mm。结论除C4根、C6根、T2根、内侧束和后束外,性别不同,其臂丛神经解剖学长度差异均有统计学意义。提示在临床麻醉及手术治疗臂丛神经损伤时一定要注意。     

Bilateral variant contributions in the formation of median nerve

Bilateral variations in the formation of median nerve (Mn) and the recurrent course of its communications with musculocutaneous nerve (MCn) are very rare. These bilateral anomalies were observed during a routine dissection of the upper limbs of an adult male cadaver in the Department of Anatomy, PGIMER, Chandigarh. On both the sides, Mn was formed by the union of three roots. There was an additional lateral root on both sides. On the right side it was a contribution from the lateral cord and on the left it arose from the anterior division of the middle trunk. On the left side the lateral cord was formed distal than usual in relation to the second part of the axillary artery. On the right side a communicating branch arising from the additional lateral root followed a recurrent course and divided into two to unite separately with medial root of median, while on the left side a single communicating branch from an additional lateral root united with the medial root of median. Recurrent course of the communicating branch between lateral root of median and medial root of median has not been reported earlier. On the right side the MCn after piercing the coracobrachialis gave another communicating branch, which joined the Mn at the level of insertion of deltoid.     

膈神经移位至臂丛上干前股的临床应用及疗效分析

目的：报道膈神经移位至臂丛上干前股的临床应用，分析疗效欠佳的原因并探讨应对措施。方法：回顾白1999年3月-2005年2月行膈神经移位至臂丛上干前股术式的38例患者手术情况，对肌皮神经恢复情况进行随访并功能评定，并对影响疗效的各因素进行分析以探讨相应的防治措施。结果：获15个月以上随访患者共29例，优良率为62．1％，功能恢复优良组与非优良组患者的病程及牵拉伤比率存在显著性差异（P〈0.05）。再手术探查发现手术失败的原因有：神经吻接口张力大、存在臂丛的组成变异及多段损伤等。基于神经解剖特点，作者针对减低膈神经吻接口张力提出了手术改良措施并取得满意的疗效。结论：影响该术式疗效的因素有多种，严格把握手术适应症及术中仔细探查是提高治疗效果的关键；通过术式改良可有效降低神经吻接口张力，有助于神经恢复。     

Surgical anatomy of the platysma motor branch as a donor for transfer in brachial plexus repair

Object  Nerve transfers have become a major weapon in the battle against brachial plexus lesions. Recently, a case involving the successful use of the platysma motor branch to re-innervate the pectoralis major muscle was reported. The present anatomical study was conducted to clarify the surgical anatomy of the platysma motor nerve, in view of its potential use as a donor for transfer. Methods  Microsurgical dissections of the facial nerve and its terminal branches were performed bilaterally in five formaldehyde-fixed cadavers, thereby yielding ten samples for study. The relationships between the platysma motor branch and adjacent structures were studied and measurements performed. Specimens were removed and histologically studied. Results  The platysma branch of the facial nerve was found to arise from the cervicofacial trunk. In five instances, one main nerve innervated the platysma muscle, and there was a smaller accessory nerve; in four cases, there was just a single branch to the muscle; and in one case, there was a main branch and two accessory branches. The distance between the gonion and the platysma motor branch averaged 0.8 cm (range 0.4–1.1 cm). The platysma branch received thin anastomotic rami from the transverse superficial cervical plexus. The neural surface of the platysma motor branch, on average, was 76% the surface area of the medial pectoral nerve. Conclusion  The anatomy of the platysma motor branch is predictable. Contraction of the platysma muscle is under voluntary control, which is an important quality for a donor nerve selected for transfer. The clinical usefulness of platysma motor branch transfer still must be elucidated.     

大鼠副神经主干及其与颈丛交通支的神经纤维性质研究

目的运用乙酰胆碱酯酶组化法鉴别大鼠副神经主干及其与颈丛交通支的神经纤维性质,通过显微镜计数得出副神经主干的神经纤维数目,为临床提供一定的解剖学依据。方法运用乙酰胆碱酯酶组化法鉴别大鼠副神经与颈丛交通支的纤维性质．并用显微镜计数副神经主干的纤维数目。结果①大鼠副神经主干经乙酰胆碱酯酶组化法染色结果为混合性反应。②大鼠副神经主干的平均神经纤维总数为（179．06±31．78）根,其中运动神经纤维（160．83±32．86）根,感觉神经纤维（18．23±7．39）根。③大鼠副神经与颈丛交通支的神经纤维经乙酰胆碱酯酶组化法染色结果为阴性反应。结论大鼠副神经主干的神经纤维性质为混合性,以运动性神经纤维为主;大鼠副神经与颈丛交通支的神经纤维性质为感觉性。     

幼年大鼠臂丛根性损伤模型的构建及其评价

目的：构建幼年大鼠臂丛损伤动物模型并对该模型进行评价。方法：选取20只幼年（P18）SPF级SD大鼠，手术撕脱实验组大鼠左侧臂丛根（C5～C7），造成大鼠臂丛根性撕伤，观察大鼠行为学和脊髓前角运动神经元的组织病理学变化。结果：实验组SD大鼠行为学出现明显异常，并且脊髓前角运动神经元在数量上较对照组显著减少；透射电镜显示实验组脊髓前角运动神经元超微结构也出现明显变化。结论：该方法可成功构建幼年SD大鼠臂丛根性撕脱伤动物模型，为分娩性臂丛损伤研究提供了一个科学可行的实验平台。     

超声平面外技术联合神经刺激器腋路动脉旁注药臂丛神经阻滞效果研究

目的 探讨超声平面外技术联合神经刺激器引导腋路动脉旁注药臂丛神经阻滞的效果。方法 选择2015年9月—2016年9月河北医科大学第三医院单侧肘关节下骨折择期行手术治疗的60例患者进行前瞻性研究。60例患者按随机数字表法分为观察组、对照组,每组30例。观察组采用超声平面外技术联合神经刺激器行腋路动脉旁注药臂丛神经阻滞,对照组采用超声平面内技术联合神经刺激器行腋路臂丛神经阻滞。观察比较两组患者麻醉操作时间、麻醉起效时间、感觉阻滞效果、运动阻滞效果、对止血带耐受情况、麻醉并发症发生情况及手术时间。结果 两组60例患者均顺利完成手术,术中无刺破血管、局麻药中毒等并发症发生。两组间比较,观察组麻醉操作时间(6.0±1.2)min,短于对照组的(11.5±2.1)min;麻醉起效时间(13.0±1.7)min,长于对照组的(7.8±1.5)min;运动完全阻滞率为53.3%(16/30),低于对照组的90.0%(27/30),差异均有统计学意义(t=12.464、-12.781,χ²=9.932,P值均﹤0.01);而两组感觉阻滞效果、止血带耐受、手术时间等差异均无统计学意义(P值均＞0.05)。结论 超声平面外技术联合神经刺激器腋路动脉旁注药臂丛神经阻滞麻醉操作简单、安全,效果确切,有很好的临床应用价值。     

Scapular deformity in obstetric brachial plexus palsy: a new finding

While most obstetric brachial plexus palsy patients recover arm and hand function, the residual nerve weakness leads to muscle imbalances about the shoulder which may cause bony deformities. In this paper we describe abnormalities in the developing scapula and the glenohumeral joint. We introduce a classification for the deformity which we term Scapular Hypoplasia, Elevation and Rotation. Multiple anatomic parameters were measured in bilateral CT images and three-dimensional CT reconstruction of the shoulder girdle of 30 obstetric brachial plexus palsy patients (age range 10 months-10.6 years). The affected scapulae were found to be hypoplastic by an average of 14% while the ratio of the height to the width of the body of scapula (excluding acromion) were not significantly changed, the acromion was significantly elongated by an average of 19%. These parameters as well as subluxation of the humeral head (average 14%) and downward rotation in the scapular plane were found to correlate with the area of scapula visible over the clavicle. This finding provides a classification tool for diagnosis and objective evaluation of the bony deformity and its severity in obstetric brachial plexus palsy patients.     

臂丛分支的CT定位研究及在Bristow-Latarjet术式的临床意义

目的　研究臂丛分支在肩胛下肌前方的CT定位,提高Bristow-Latarjet术式临床操作时安全范围的认知。 方法　福尔马林固定的上肢标本16侧（男10,女6）。解剖和使用显影线标记16侧肩的臂丛分支（肌皮神经、腋神经、桡神经）在肩胛下肌前方的位置、行程,CT水平位上测量肩关节内旋45°、中立位、外旋45° 3个体位2~5点位置肌皮神经到关节盂的距离及成角规律,所得数据经统计学处理。 结果　⑴臂丛在肩胛下肌前方,由内往外神经的排列分别是腋神经、桡神经、肌皮神经。⑵CT水平位上测量肌皮神经在3个体位的数据,组间比较：角度上比较,2~5点位置的内旋位与中立位、与外旋位比较具有统计学意义（均P<0.05）;距离上比较：2点位置的外旋位与中立位、与内旋位比较具有统计学意义（均P<0.05）,中立位与内旋位比较无统计学差异（P=0.15）;3~5点位置的内旋位与中立位、与外旋位比较具有统计学意义（均P<0.05）。5点位置的外旋位与中立位比较无统计学差异（P=0.07）。组内比较：内旋位2点位置的角度分别与3~5点位置比较,均有统计学差异（均P<0.05）,3~5点位置的两两比较,均无统计学差异（均为P>0.05）。 Pearson分析：盂的高度HL与内旋位2点位置的角度呈负相关,与3点位置的角度呈正相关,与内旋位2点位置的距离呈负相关,与3~5点位置的距离呈正相关。 结论　肩关节内旋45°时肌皮神经的安全范围显著大于中立位及外旋45°,建议内旋位操作。     

基于CT的髌骨下极骨折分型

目的 基于三维CT图像对髌骨下极骨折分型。 方法 回顾性分析本院2018年5月至2020年11月67例髌骨下极骨折的三维CT图像并分型。用Kappa系数评估观察者间可信度和观察者自身可信度。 结果 髌骨下极骨折分为无移位骨折（Ⅰ型）和移位骨折（Ⅱ型）两型。移位骨折可分为3个亚型：Ⅱa型,大块型骨折,包括髌骨下极1枚孤立性骨折块,或2枚较大的骨折块;Ⅱb型,粉碎性骨折,多枚较小的骨折块,包括冠状位和矢状位骨折块;Ⅱc型,袖套样撕脱骨折,沿髌骨下极整个弧面的呈内外方向的长弧形骨折,多为粉碎性的,骨折块非常薄。本研究中Ⅰ型8例,Ⅱa型11例,Ⅱb型42例,Ⅱc型6例。观察者之间的可信度平均K值为0.782（0.682 ~ 0.896）,基本可信;观察者自身可信度平均K值为0.837（0.786 ~ 0.884）,完全可信。 结论 本文髌骨下极骨折分型方法有较高的可信度及可重复性,对临床有一定的指导意义。     

Microanatomical study on the functional origin and direction of the thoracodorsal nerve from the trunks of brachial plexus

Ipsilateral C7 nerve root transfer or neurotization has been used for the repair of brachial plexus avulsions. In this procedure, the ipsilateral C7 nerve root is used as a donor nerve and is implanted into the damaged nerve of the brachial plexus in order to reinnervate distal muscles. However, this procedure may result in unintended injury to the thoracodorsal nerve, which receives motor fascicles form the cervical nerves of C6, C7, and C8, but mainly from C7. Damage to the thoracodorsal nerve ultimately results in weakness or paralysis of the latissimus dorsi muscle, which it innervates. In the present study, 20 adult cadaveric brachial plexus specimens and 3 fresh specimens were dissected using microscopy. The origin and direction of motor fascicles from the three trunks of the brachial plexus to the thoracodorsal nerve were investigated. Motor fiber counts of C7 and the thoracodorsal nerve were also performed. Several observations can be made: (1) The origin of the thoracodorsal nerve can be divided into three types: Type A, the thoracodorsal nerve originated from the superior and middle trunks; Type B, the thoracodorsal nerve originated from the inferior and middle trunks; and Type C, the thoracodorsal nerve originated from all three trunks. (2) More than 52% of the motor fibers in the thoracodorsal nerve originated in the C7 nerve root. (3) Motor fascicles from C7 to the thoracodorsal nerve were mostly localized in the posterior-internal part of C7 at the trunk-division boundary. In conclusion, we suggest that: (1) Because of variation in the origin of the thoracodorsal nerve, electromyography should be routinely performed intraoperatively during C7 nerve root transfer to determine the origin type and avoid thoracodorsal fascicle injury. (2) Preservation of the posterior-internal part of C7 (selective C7 transfer) can protect thoracodorsal nerve fascicles from damage and prevent postoperative dysfunction of the latissimus dorsi muscle.     

The efficacy of end-to-end and end-to-side nerve repair (neurorrhaphy) in the rat brachial plexus

Proximal nerve injury often requires nerve transfer to restore function. Here we evaluated the efficacy of end-to-end and end-to-side neurorrhaphy of rat musculocutaneous nerve, the recipient, to ulnar nerve, the donor. The donor was transected for end-to-end, while an epineurial window was exposed for end-to-side neurorrhaphy. Retrograde tracing showed that 70% donor motor and sensory neurons grew into the recipient 3 months following end-to-end neurorrhaphy compared to 40–50% at 6 months following end-to-side neurorrhaphy. In end-to-end neurorrhaphy, regenerating axons appeared as thick fibers which regained diameters comparable to those of controls in 3–4 months. However, end-to-side neurorrhaphy induced slow sprouting fibers of mostly thin collaterals that barely approached control diameters by 6 months. The motor end plates regained their control density at 4 months following end-to-end but remained low 6 months following end-to-side neurorrhaphy. The short-latency compound muscle action potential, typical of that of control, was readily restored following end-to-end neurorrhaphy. End-to-side neurorrhaphy had low amplitude and wide-ranging latency at 4 months and failed to regain control sizes by 6 months. Grooming test recovered successfully at 3 and 6 months following end-to-end and end-to-side neurorrhaphy, respectively, suggesting that powerful muscle was not required. In short, both neurorrhaphies resulted in functional recovery but end-to-end neurorrhaphy was quicker and better, albeit at the expense of donor function. End-to-side neurorrhaphy supplemented with factors to overcome the slow collateral sprouting and weak motor recovery may warrant further exploration.     

膈神经与肋间神经移位修复臂丛神经根性撕脱伤

BACKGROUND: Phrenic nerve transfer and intercostal nerve transfer are the accepted surgery strategies for the treatment of brachial plexus root avulsion injuries; however, which surgery is more suitable for the repair remains inconclusive. OBJECTIVE: To observe the treatment outcomes of brachial plexus root avulsion injuries by transferring the phrenic nerve to the anterior division of the upper trunk of brachial plexus and the intercostal nerve to the musculocutaneous nerve. METHODS: Twenty patients with brachial plexus root avulsion injuries were included. Among them, 9 were treated with phrenic nerve transfer to the anterior division of the upper trunk of brachial plexus (phrenic nerve transfer group), and 11 were treated with intercostal nerve transfer to the musculocutaneous nerve (intercostal nerve transfer group). Postoperative follow-up ranged from 15 to 36 months. Incision length, blood loss, and operation time were recorded. Muscle strength of the biceps and elbow flexion angle were evaluated. The repair outcome was evaluated by assessing the functional recovery of musculocutaneous nerve according to the criteria issued by the Branch of Hand Surgery of Chinese Medicine Association, and the excellent and good rate was calculated. RESULTS AND CONCLUSION: The excellent and good rate was 66.7% and 63.6%, respectively, in phrenic nerve transfer group and intercostal nerve transfer group, which is not significantly different between both groups (P > 0.05). Smaller length of operation incision, reduced blood loss, and shorter operation time were found in the phrenic nerve transfer group. Two and three patients in bad recovery were in phrenic nerve transfer and intercostal nerve transfer groups, respectively. These findings suggest that the two kinds of surgery strategies for the repair of brachial plexus root avulsion injuries can obtain good results in the functional recovery of elbow flexion. Phrenic nerve transfer exerts superiorities in operation incision, blood loss and operation time. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Technical note: the design of a stereotactic frame for direct MRI-anatomical correlation of the brachial plexus

The purpose of this study was to identify optimal magnetic resonance imaging (MRI) conditions to visualize discrete alterations of brachial plexus components, as part of a biomechanical study of minor nerve compression syndromes. A method was developed allowing direct comparison between the MRI image and the subsequently obtained matching anatomic section of the same specimen. We designed a stereotactic frame to obtain the precise orientation of the MRI plane with reference to the specimen and adapted a vertical band saw for multiplanar sectioning of cadaveric specimens. Two cadaveric upper quadrants were examined by MRI (TR 450 ms, TE 13 ms, pixel matrix 512 × 512 and FOV 23–26 cm) and anatomical slices were produced. One specimen was sectioned axially, while the second specimen was sectioned in an oblique plane corresponding to the natural longitudinal axis of the upper part of the brachial plexus. MR images and the corresponding slices exhibited a strong correlation. This correlation was checked by using vitamin A pearls as landmarks. MR images revealed more detail after the correlating anatomical slices were analyzed. The present study shows that the method is suited for direct MRI-anatomic comparison of the brachial plexus and is also proposed for application to other topographical regions.     

大鼠失肌皮神经与屈肘重建后供受体肌内亚型乙酰胆碱受体的表达

目的　探索失肌皮神经与胸大肌部分移位重建屈肘后供受体肌内成熟型与胚胎型乙酰胆碱受体（ε-AChR和γ-AChR）的表达变化,旨在为其术后肌萎缩的防治提供新视角。 方法　将70只成年SD大鼠随机分为A组（正常组）;B1、B2组（肌皮神经切断2、4 周组）;C1、C2组（假移植术2、4 周组）;D1、D2组（胸大肌部分移位缝合至肱二头肌腱重建屈肘功能术2、4 周组）,共7组,每组10只。称量肌重,HE染色后测量肌纤维横切面积,RT-PCR和Western blot技术检测ε-AChR和γ-AChR的mRNA与蛋白表达变化。 结果　与A组比较,B组大鼠跛行,觅食受限,肱二头肌（受体肌）湿重逐渐减轻,肌纤维横切面积减小,ε-AChR mRNA和蛋白表达下调,γ-AChR 出现重新表达并逐渐上调;C组中上述改变进行性加重,D组的上述改变逐渐恢复,且胸大肌（供体肌）内ε和γ-AChR仅一过性异常表达。 结论　大鼠失肌皮神经损伤后,行胸大肌部分移位重建屈肘功能术,能上调受体肌内ε-AChR表达和下调γ-AChR的表达而改善屈肘功能。