Anatomic course of the medial cutaneous nerves of the arm

The medial antebrachial cutaneous nerve and the medial brachial cutaneous nerve were dissected in twenty fresh cadaver extremities. These nerves have a variable number of cutaneous branches ranging from four to twelve, with an average of eight. Branches always originated medially in both nerves and ran in an anterolateral direction. In all the medial antebrachial cutaneous nerves, there were three to five terminal branches directly overlying the medial epicondyle and supplying the skin over the olecranon. The course of this nerve is predictable relative to the basilic vein and the medial epicondyle. There was a ninety percent incidence of communication between the medial brachial cutaneous nerve and the intercostobrachial cutaneous nerve. The standard incision used for surgery of the ulnar nerve at the elbow will cut the terminal branches of the medial antebrachial cutaneous nerve one hundred percent of the time, and the terminal branches of the medial brachial cutaneous nerve eighty percent of the time, if they are not identified. A posterior approach for transposition of the ulnar nerve would avoid damage to these nerves.     

前臂内侧皮神经后支与肘管综合征手术切口的解剖关系

目的 观察肘部前臂内侧皮神经(medial antebrachial cutaneous nerve,MACN)后支的解剖特征,探讨在肘管综合征松解手术中防止其医源性损伤的方法.方法 解剖10具(20侧)成人上肢标本,并对12例肘管综合征手术患者,在肱骨内上髁远、近各8 cm范围内,观察NACN后支的数目、横跨角度并测定其与手术切口(内上髁前1 cm)的交汇部位.结果 32侧肢体共记录到62支MACN 后支,平均每侧肢体为1.9支.其中1支者8侧(25.0%,均位于内上髁远侧),2支者19侧(59.4%),3支者4侧(12.5%),4支者1侧(3.1%).位于内上髁下方者37支(59.7%),内上髁上方者25支(40.3%).这些后支与切口线的交角均大于45°,即皮神经是横向跨过切口线的.所有标本(100%)均至少有1支后支从内上髁远侧跨过切口线,其距内上髁的平均距离为[(2.9±2.3)cm,x-±s,下同];在68.8%的标本中至少有1支后支从内上髁近侧跨过切口线,其距内上髁的平均距离为(2.1±1.8)cm.结论 MACN后支至少有1支横跨肘管综合征的手术切口线,了解其位置关系并在皮下组织中仔细解剖分出保护,有助于避免误伤.     

Editorial Commentary: Safety in Anteromedial Elbow Portal Placement? Go North!

Since iatrogenic injury to surrounding structures is more likely in the elbow than in the other major joints, many studies have examined the relationship of elbow arthroscopy portals to the at-risk anatomy. In accessing the anterior compartment of the elbow from the medial side, the brachial artery and median, ulnar, and medial antebrachial cutaneous nerves are at risk. Factors that improve the safety of this approach include the use of a proximal versus distal anteromedial portal, a distended versus and nondistended joint, and a flexed versus extended elbow position, all of which result in an approximate margin of safety of 2 cm from the deep at-risk structures.     

Anatomy of the anterior interosseous innervation of the pronator quadratus: evaluation of structures at risk in the single dorsal incision wrist denervation technique

PURPOSE: Patients with chronic wrist pain often are treated with wrist denervation, which typically involves transecting both the anterior interosseous nerve (AIN) and the posterior interosseous nerve. A single dorsal incision approach is an improvement over the more traditional multiple-incision technique. The purpose of our study was to describe the branches of the AIN to the pronator quadratus and evaluate the risk of denervation with the single dorsal incision technique. METHODS: Twelve fresh-frozen cadaver forearms were dissected. The branches of the AIN to the pronator quadratus were identified and the individual branch points were measured from the articular edge of the distal radius. Wrist denervation was then performed on each specimen through the single dorsal incision (as suggested by Berger). RESULTS: There were an average of 3 branches from the AIN to the pronator quadratus. All forearms had at least 1 branch to the pronator quadratus more proximal to the distal end of the dorsal skin incision; however, in only 2 of the forearms was the most proximal branch more than 2 cm proximal to the distal end of the dorsal skin incision. CONCLUSIONS: Wrist denervation through the recommended single dorsal incision poses a serious risk for completely denervating the pronator quadratus. Therefore the resection of the AIN must be performed close to the distal margin of the pronator quadratus.     

Innervation of the wrist joint and surgical perspectives of denervation

PURPOSE: Because our experience with the techniques used in denervation surgery of the wrist joint often has proven insufficient in treating chronic pain we conducted an anatomic study to clarify the exact contributions of the nerves supplying the wrist joint. Our goal was to reveal all periosteal and capsular nerve connections and if necessary adjust our technique used in denervation surgery. METHODS: Innervation of the wrist joint was investigated by microdissection and histologic examination of 18 human wrists. An acetylcholinesterase method was used to identify the nerves, both in whole-mount preparations and in sections. RESULTS: We found that the main innervation to the wrist capsule and periosteal nerve network came from the anterior interosseous nerve, lateral antebrachial cutaneous nerve, and posterior interosseous nerve. The palmar cutaneous branch of the median nerve, the deep branch of the ulnar nerve, the superficial branch of the radial nerve, and the dorsal branch of the ulnar nerve also were found to have connections with the capsule. The periosteal nerve branches did not appear to play a major role in the innervation of the capsule and ligaments; here the specific articular nerve branches proved more important. The posterior and medial antebrachial cutaneous nerves did not connect to the wrist capsule or periosteum but rather terminated in the extensor and flexor retinaculum. CONCLUSIONS: Based on our findings we propose to denervate the wrist by making 2 incisions. With one palmar and one dorsal incision it should be possible to disconnect the periosteum from the capsule and interrupt the majority of the capsular nerve branches.     

阻断部分臂丛神经下干分支对健侧颈7移位下干后神经再生的影响

目的 以大鼠健侧颈7直接修复臂丛神经下干为模型,探讨阻断下干分支前后,尺神经和正中神经神经纤维数量和质量的变化.方法 雌性SD大鼠40只,随机分成4组.A组:健侧颈7直接修复下干,并从下干发出处阻断下干后股、胸前内侧神经、前臂内侧皮神经;B组:健侧颈7直接修复下干,并从下干发出处以远1 cm处阻断下干后股、胸前内侧神经、前臂内侧皮神经;C组:健侧颈7直接修复下干,并从下干发出处切断后股;D组:对照组.术后比较尺神经、正中神经、胸前内侧神经和前臂内侧皮神经的神经纤维数量、神经纤维密度(p)、神经纤维数占下干神经纤维总数百分比、神经纤维直径、有髓神经纤维面积与相应分支神经总面积比(N Ratio).结果 尺神经和正中神经中,神经纤维数量、神经纤维密度、正中神经与尺神经分别占下干神经纤维百分比、神经纤维直径、不同直径神经纤维百分比、N Ratio,A、B、C三组间差异均无统计学意义.前臂内侧皮神经和胸前内侧神经中,上述各检测指标B、C组间均无明显差异.结论 健侧颈7直接移位下干后,在根部及根部以远1 cm处阻断胸前内侧神经及前臂内侧皮神经后,对尺神经、正中神经、前臂内侧皮神经残端和胸前内侧神经残端中神经纤维的数量和质量无明显影响.

Abstract：

Objective To explore the changes of the nerve fibers from median and ulnar nerves after cutting the branches of lower trunk which was repaired by the contralateral C7.Methods Forty female SD rats were divided into A, B, C and D groups randomly.In group A,the contralateral C7 root was transferred to lower trunk directly, and the posterior division of lower trunk, medial anterior thoracic nerve and the medial antebrachial cutaneous nerve were severed at the beginning of them;In group B, the contralateral C7 root was trarsferred to lower trunk directly, and the posterior division of lower trunk, medial anterior thoracic nerve and the medial antebrachial cutaneous nerve were severed at the point which was 1 cm away from the beginning of above branches;In group C, the contralateral C7 root was transferred to lower trunk directly, and the posterior division of lower trunk was severed at the beginning of it;In group D, control group.After the operation, myelinated fiber count, nerve fiber density, the percentage of the number of nerve fiber from branch accounting for that from lower trunk, nerve fiber diameter,the percentage of nerve fibers with different diameters and N Ratio were carried out to evaluate the outcome of each group.Results Myelinated fiber count, nerve fiber density, the percentage of the number of nerve fiber from branch accounting for that from lower trunk, nerve fiber diameter,the percentage of nerve fibers with different diameters and N Ratio in ulnar and median nerve, there were no difference between group A, group B and group C ( P ＞ 0.05).Conclusion After the medial anterior thoracic nerve and medial antebrachial cutaneous nerve, repaired by the contralateral C7, were severed at the beginning and at the point which was 1 cm away from the beginning of above branches, the changes of the quantity and quality of the nerve fibers from median and ulnar nerves were not significant.     

足背中间皮神经营养血管远端蒂皮瓣的解剖研究与初步应用

目的为足背中间皮神经营养血管皮瓣设计提供解剖学依据,并报道临床应用效果。方法32侧乳胶灌注的成人下肢标本,解剖观测足背中间皮神经及其营养血管的来源、走行、分支分布及其外径。在解剖学研究的基础上,2004年6月-2005年10月设计足背中间皮神经营养血管皮瓣修复足部创面共4例5个皮瓣。结果足背中间皮神经续于腓浅神经,行于踝间线时位于其中点外侧1.3±0.6cm,直径2.05±0.56mm。神经主干于踝间线远端2.8±1.3cm处发出分支,分布于2、3、4跖背及足趾皮肤。足背中间皮神经营养血管平均每侧5.1支。最为恒定的营养血管近端来自胫前动脉、足背动脉的皮支,远端来自跖背动脉,分别位于踝间线近端4.3±0.4cm,直径0.82±0.13mm;第3趾蹼尖近端1.6±0.3cm,直径0.42±0.07mm;第4趾蹼尖近端1.5±0.3cm,直径0.49±0.09mm。临床应用4例5个皮瓣,术后均完全成活,随访4-10个月。外形美观,质地良好。结论足背中间皮神经营养血管远端蒂皮瓣血供可靠,是一种理想的修复足部创面的皮瓣供区。     

新型微创前置肱骨中下段解剖锁定钢板的设计及相关解剖研究

目的 探讨应用自行研制的3.5 mm新型前置肱骨中下段解剖锁定钢板微创治疗肱骨干中下段骨折的可行性和安全性.方法 新鲜冷冻成人上肢6具,分别于上臂前侧远近端做3 cm皮肤切口,通过肌下隧道插入钢板,经切口打入螺钉固定.原位解剖重要神经结构,观察其与钢板的关系,测量桡神经在不同位置与钢板外侧缘、钢板最远端内侧与正中神经、螺钉头部与桡神经沟处桡神经的距离.结果 新增前置肱骨中下段解剖锁定钢板远端的绝大部分被肱肌覆盖,其与桡神经、肌皮神经及正中神经之间隔有肱肌肌腹,钢板与桡神经之间分别在穿经外侧肌间隔以及冠状窝水平的距离平均分别为14.53 mm和8.38 mm,桡神经穿经外侧肌间隔至冠状窝上缘连线中点处的平均距离为8.39 mm;屈肘80°和伸肘0°位时钢板最远端内侧与正中神经的距离平均分别为11.89 mm和l0.53mm,由近向远的第3枚螺钉头部与桡神经沟近侧缘的距离平均为5.90 mm.结论 采用自行研制的新型前置解剖锁定钢板微创固定肱骨干中下段骨折理论上是可行且安全的.

Abstract：

Objective To verify the feasibility and safety of a self-designed anatomical anterior locking plate for minimally invasive treatment of mid-distal humeral fractures. Methods Six fresh-frozen cadaveric specimens of upper extremity were used for the present anatomic study.A 3 cm incision was made on the anterior side of the arm between the deltoid muscle and biceps muscle and another 3 cm incision was made along the lateral side of biceps muscle proximal to the cubital crease to expose the anterior cortex.The plate was inserted from the distal incision proximally and positioned on the anterior side of the humeral shaft.The biceps muscle and brachialis were dissected to expose the radial,musculocutaneous and median nerves in situ.Relationships between the plate and nerves were observed.The distances between the lateral border of the plate and the radial nerve were measured where the nerve pierced the lateral intermuscular septum and at the point above the coronoid fossa and at the middle of the above 2 points.The distances between the distal end of the plate and the median nerve were measured when the elbow was in 80° flexion and full extension.The distance between the head of the third proximal screw and the spiral groove was also measured. Results Most part of the plate was covered by the brachial muscle.There was no direct contract between the plate and the radial,musculocutaneous and median nerves,all separated by the muscle belly of the brachialis.The average distances between the lateral border of the plate and the radial nerve where the nerve pierced the lateral intermuscular septum and at the superior edge of the coronoid fossa and at the middle of the 2 points were 14.53 mm (range,13.1 to 17.1 mm),8.38 mm (range,4.2 to 11.3 mm) and 8.39 mm (range,0 to 13.9 mm) respectively.The average minimum distances between the medial border of the distal end of the plate and the median nerve when the elbow was in 80° flexion and full extension was 11.89 mm (range 9.6 to 15.5 mm) and 10.53 mm (range 9.0 to 12.1 mm) respectively.The average distance between the head of the third proximal screw and the spiral groove was 5.90 mm (range,4.2 to 7.1 mm). Conclusions Our novel anatomical anterior locking plate is theoretically safe for the minimally invasive treatment of mid-distal humeral fractures.     

The cutaneous innervation of the dorsal hand: detailed anatomy with clinical implications

PURPOSE: Detailed knowledge of the anatomy of the cutaneous innervation to the dorsal surface of the hand is valuable information. Because surgical access to the wrist often is obtained via the dorsal skin it would be helpful particularly to delineate an area where surgical incisions would not injure underlying nerves. METHODS: Thirty cadaver forearms were dissected carefully to examine in detail the anatomy of the lateral antebrachial cutaneous nerve, the superficial branch of the radial nerve, and the dorsal branch of the ulnar nerve. Each hand then was evaluated for an area free of any major nerve branches over the dorsal wrist. RESULTS: Although the innervation to the dorsal hand varies certain patterns exist. The innervation pattern between the superficial branch of the radial nerve and the dorsal branch of the ulnar nerve is distributed evenly, dual innervation is frequent between the 2 nerves, and the lateral antebrachial cutaneous nerve is a common contributor to the innervation of the thumb. The superficial branch of the radial nerve and the dorsal branch of the ulnar nerve have identifiable branching patterns and have been classified according to a system developed for this study. CONCLUSIONS: Two classification systems based on detailed dorsal hand cutaneous innervation patterns can be used to specify the placement of a safe dorsal skin incision away from major nerve branches.     

肘下动脉穿支蒂前臂外侧皮神经营养血管皮瓣的解剖基础

目的 为肘下动脉穿支蒂前臂外侧皮神经营养血管皮瓣修复肘部软组织缺损提供解剖学基础.方法在30侧动脉内灌注红色乳胶的成人上肢标本上解剖观查:①前臂外侧皮神经的走行与分布;②肘下动脉与前臂外侧皮神经营养血管间吻合关系.另在1侧新鲜标本上进行摹拟手术设计.结果①前臂外侧皮神经主干行于前臂桡侧,分布于前臂外侧1/3区域;②营养血管为多节段、多源性,其中肘下动脉的位置相对恒定,在头静脉与深静脉系统的交通支形成的倒"V"状顶点到达皮肤,并分出众多的细小血管与前臂外侧皮神经的神经旁和神经干血管链的分支密切吻合.结论 可形成肘下动脉穿支蒂前臂外侧皮神经营养血管皮瓣顺行转位修复肘部软组织缺损.

Abstract：

Objective To provide anatomical basis for lateral antebrachial neurocutaneous flap pedi-cled with inferior cubital artery perforator in repairing tissue defects around elbow joint. Methods Thirty embalmed upper limbs of adult cadavers perfused with red latex were used for this study, and followings were observed:①The course and distribution of lateral antebrachial cutaneous nerve; ②Anastomoses between inferior cubital artery and nutrient vessels of lateral antebrachial cutaneous nerve. Mimic operation was performed on other side of fresh specimen. Results ①The main trunk of lateral antebrachial cutaneous nerve (LACN) lined in the radial forearm and distributed in the 1/3 region of lateral forearm. ①The nutritional vessels of the flap were plurisegmental and polyphyletic. The inferior cubital artery which was relatively constant reached to skin through "V"-shaped peak formed by communicating branches of cephalic vein and deep venous system. They also gave off large number of small veins, which closely aligned with perineural branches and neural stem vascular chain of lateral antebrachial cutaneous nerve. Conclusion The lateral antebrachial neurocutaneos flap pedicled with inferior cubital artery perforator can be formed to repaire tissue defects around elbow joint.     

Arthroscopic anatomy of the lateral elbow: A comparison of three portals

Ten fresh cadaveric elbows were used to evaluate the proximity of the radial nerve and its branches to three anterolateral portals. A proximal anterolateral portal used routinely at our institution and located 2 cm proximal and 1 cm anterior to the lateral epicondyle was compared with the distal anterolateral portal described by Andrews and with a mid-anterolateral portal. The three portals were initially established without joint distention while the elbows were flexed 90°. Measurements were then obtained with and without joint distention at flexion angles of 0° and 90°. The radial nerve was found to be an average distance of 3.8 mm at extension and 7.2 mm at 90° of flexion from the distal anterolateral portal, located 3 cm distal and 1 cm anterior to the lateral epicondyle. Conversely, the distance between the proximal anterolateral portal cannula and the nerve was statistically greater (p < 0.05), averaging 7.9 mm in extension and 13.7 mm in flexion. The remaining anterolateral portal, located 1 cm directly anterior to the lateral epicondyle, was found to be at a statistically greater average distance from the nerve than was the distal anterolateral portal but statistically closer than was the more proximal portal. The ability to visualize the joint arthroscopically was assessed using the three portals, and although the ulnohumeral joint could be adequately seen using all portals, radiohumeral joint visualization was most complete and technically easiest using the most proximal portal. The proximal anterolateral portal, used in >100 elbow anthroscopies without evidence of radial nerve injury, is recommended for use as the standard lateral access site, allowing excellent visualization while maximizing the distance from the radial nerve throughout the elbow's range of motion.     

A posterior approach to the elbow joint based on the blood supply to the triceps muscle

We describe a posterior approach to the elbow joint based on anatomical studies of the blood supply to the triceps muscle, and observation of the musculotendinous insertion of triceps. These studies demonstrated that the triceps muscle is essentially supplied by end arteries. Any distal-proximal anastamoses from the collateral branches of the radial and ulnar arteries, occur at the small vessel level. The insertion of triceps is musculotendinous with an aponeurosis consisting of two laminae, one superficial and one deep, as well as direct muscle insertion into the olecranon. Our approach provides an excellent exposure of the distal humerus without the division of any fibers of triceps preventing any muscle necrosis and scarring. We formally dissect the two laminae of the triceps aponeurosis, and divide the deeper intramuscular aponeurosis 2 cm proximal to the olecranon. At closure, correct tensioning of the intramuscular aponeurosis allows for soft tissue balancing and optimum elbow function. We use this approach for total elbow replacement, open reduction and internal fixation of distal humerus fractures and in the open reduction of displaced supracondylar fractures in children. We have had no cases of a triceps tendon dehiscence in over 400 cases.     

Posteromedial elbow approach for treatment of olecranon and coronoid fractures

This article illustrates the posteromedial elbow approach to address both coronoid and olecranon ulnar fractures. Olecranon and coronoid fractures were simulated in 6 cadaveric elbows. The osteotomies were made with a percutaneously placed osteotome through the olecranon fossa and the elbow joint. To expose these osteotomies, each elbow underwent a posterior midline skin incision, medial skin flap elevation, anterior transposition of the ulnar nerve, and subperiosteal elevation of the ulnar arm of the flexor carpi ulnaris. Fracture fixation was performed with posteriorly placed plates and screws. Each procedure was documented using radiographs and digital photography. The 6 procedures illustrated a surgical approach that is expedient in exposing the olecranon, medial elbow joint, and medial coronoid wall. All osteotomies were anatomically reduced and internally fixed in this setting. This technique allowed supine positioning of the cadaver and the use of an arm table for radiographic imaging in the lateral and anteroposterior planes. The direct visualization of both the coronoid and olecranon fracture facilitated anatomic reduction using standard surgical techniques. This technique also preserved the pronator attachment to the humerus, transposed the ulna nerve, and reapproximated the flexor carpi ulnaris fascia.     

Anatomy of the lateral antebrachial cutaneous and superficial radial nerves in the forearm: a cadaveric and clinical study

PURPOSE: To define the anatomy of the lateral antebrachial cutaneous nerve (LACN) and the superficial radial nerve (SRN) in relation to easily identifiable landmarks in the dorsoradial forearm to minimize the risk to both nerves during surgical approaches to the dorsal radius. METHODS: In this study 37 cadaveric forearms and 20 patients having distal radius external fixation were dissected to identify these nerves in relation to various anatomic landmarks. RESULTS: Based on these dissections the anatomy was divided into 2 zones that can be identified by easily visible and palpable landmarks. Zone 1 extends from the elbow to the cross-over of the abductor pollicis longus with the extensor carpi radialis brevis and longus. Zone 2 is distal to the cross-over. In zone 1 the 2 nerves can be differentiated through limited incisions based on their depth and anatomic location. Within this zone the SRN is deep to the brachioradialis until 1.8 cm proximal to zone 2 (9 cm proximal to the radial styloid), where it becomes superficial and pierces the fascia of the mobile wad and then remains deep to the subcutaneous fat. In contrast the LACN pierces the fascia between the brachialis and biceps muscles at the level of the elbow. In all specimens the LACN ran parallel to the cephalic vein within the subcutaneous fat. In 31 specimens it ran volar to the vein and in 5 specimens the nerve crossed under the cephalic vein at the elbow and ran dorsal to the vein in the forearm. One specimen had 2 branches with 1 on either side of the vein. Differentiation of these nerves was found to be possible through limited incisions in zone 1 during placement of external fixation pins for distal radius fractures. The LACN always was located in the superficial fat running with the cephalic vein, whereas the SRN was deeper to this nerve either covered by the brachioradialis or closely adherent to it within the investing fascia of the mobile wad. In zone 2 the nerves arborized and ran in the same tissue plane, making differentiation through limited incisions difficult. CONCLUSIONS: Dividing forearm anatomy into zones aids in understanding the complex 3-dimensional anatomy. Recognition of the consistent location of both the LACN and SRN facilitates surgical exposure. This allows localization through limited incisions during nerve repair and hardware placement, thereby enhancing uncomplicated and favorable outcomes.     

带前臂外侧皮神经营养血管筋膜皮瓣的应用解剖

目的：为带前臂外侧皮神经及其营养血管筋膜皮瓣提供形态学基础。方法：在３２侧成人上肢标本上，观测前臂外侧皮神经营养血管及其周围皮肤的供血情况。结果：前臂外侧皮神经近侧的血供为肱动脉末端和桡动脉起始部的肌皮支，起始处外径分别为１．４ｍｍ、１．１ｍｍ，穿出深筋膜前长为１．９ｃｍ、１．４ｃｍ；远侧主要为桡动脉的粗大皮支，起始处外径为０．８ｍｍ，穿出深筋膜前长０．８ｃｍ；此外，桡动脉的茎突返支及掌浅支的皮支营养其远端。其神经支在神经束间或神经旁相互吻合构成纵向（链式）血管网，并借分支与筋膜皮支所形成的皮下筋膜血管网沟通。结论：可设计带前臂外侧皮神经及其营养血管的筋膜皮瓣，顺行或逆行转位修复邻近部位的软组织缺损。     

Anatomy of the posterior antebrachial cutaneous nerve: practical information for the surgeon operating on the lateral aspect of the elbow

PURPOSE: To investigate the anatomic relationships of the posterior antebrachial cutaneous nerve (PABCN) to anatomic landmarks on the lateral side of the elbow. METHODS: The PABCN was explored in 30 cadaveric upper extremities. Distances were noted from easily identifiable structures including the lateral epicondyle, the lateral intermuscular septum, and the radial nerve. RESULTS: The path of the PABCN follows the spiral groove initially, diverging as the radial nerve pierces the lateral intermuscular septum. The PABCN emerges from the posterior compartment through a hiatus in the deep fascia at a mean of 6.6 cm proximal to the lateral epicondyle and passes a mean of 2.1 cm anterior to the lateral epicondyle. CONCLUSIONS: The anatomic relationships determined in this study should enable the surgeon to avoid injuring the PABCN when performing surgery in the lateral elbow region.     

Radial and axillary nerves. Anatomic considerations for humeral fixation

Because the axillary and radial nerves can be injured during operative exposure and fixation of the humerus, accurate delineation of their location is vital to avoid complications. The authors investigated the relationship of the radial and axillary nerves for radiographically and surgically identifiable bony landmarks. Fifty fresh human cadaveric upper extremities were dissected to identify the nerves as they crossed the lateral intermuscular septum and the humeral surgical neck, respectively. Longitudinal distances between the nerves and the superior aspect of the humeral head, the surgical neck, the superior extent of the olecranon fossa, and the distal aspect of the trochlea were measured with calipers. The average distance from the axillary nerve to the proximal humerus was 6.1 +/- 0.7 cm (range, 4.5-6.9 cm) and 1.7 +/- 0.8 cm (range, 0.7-4.0 cm) from the surgical neck. The radial nerve traversed the lateral intermuscular septum 17 +/- 2.3 cm (range, 13-22 cm) from the proximal humerus, 12 +/- 2.3 cm (range, 7.4-16.6 cm) from the olecranon fossa, and 16 +/- 0.4 cm (range, 9.0-20.5 cm) from the distal humerus, representing the approximate midpoint of the bone. Anteroposterior locking screws placed into the proximal humerus endanger the axillary nerve because it lies directly over the posterior cortex as little as 0.7 cm from the surgical neck. As the radial nerve crosses the lateral intermuscular septum more proximal than generally was thought, it is at risk during implant insertion in the distal half of the humerus. Using measurements calculated from preoperative and intraoperative imaging, the approximate position of the nerve could be determined to better plan fixation method and implant location.     

近节指背逆行岛状皮瓣修复手指皮肤缺损

目的 探讨应用多源供血的指背逆行岛状皮瓣修复手指皮肤缺损的方法及疗效.方法 2005年1月至2008年12月,应用包含指动脉背侧皮支、指固有神经背侧支营养血管和深筋膜血管网三重血供来源的多源供血近节指背逆行岛状皮瓣,修复2-5指中、末节皮肤缺损59例71指,皮瓣切取面积为2.0 cm × 1.5 cm～4.0 cm × 2.8 cm.结果 术后皮瓣全部存活,随访6个月至2年,手指外形满意,皮瓣两点分辨觉达4.5～10.0 mm,平均6.6 mm,患指近指间关节活动正常,供区无明显并发症.结论 多源供血的近节指背逆行岛状皮瓣具有血供可靠、不牺牲主要血管、皮瓣感觉恢复良好的优点,是修复手指中、末节皮肤缺损的理想术式.     

Wrist denervation and the anterior interosseous nerve: anatomic considerations

PURPOSE: Wrist denervation via resection of the distal anterior interosseous nerve (AIN) and the posterior interosseous nerve (PIN) is an effective treatment for chronic wrist pain. When performing this procedure through a dorsal approach we have been impressed by anatomic variations of the AIN. This has raised concerns about potential denervation of the pronator quadratus (PQ). The purpose of this study was to elucidate the anatomy of the AIN and PIN as encountered through a dorsal distal forearm incision. METHODS: Ten fresh-frozen cadavers were dissected. Before dissection radiographs were obtained to ensure accurate localization of the proximal ulnar head with a radiopaque marker. A dorsal approach to the distal forearm was made to identify the anatomy of the PIN and AIN. The location and diameter of all AIN branches were noted by using an operating stereoscopic microscope at x 25 magnification and a precision caliper. The PIN anatomy and size also were noted. RESULTS: The anatomy of the AIN was variable. The average AIN diameter proximal to the PQ was 1.5 mm. The average number of AIN motor branches was 4.2. The largest PQ motor branch was the first motor branch and was located at an average distance of 37.9 mm from the proximal ulnar head. The last motor branch was found an average of 23.9 mm from the proximal ulnar head. In 9 of 10 specimens the sensory branch tunneled radially through the distal PQ and innervated the periosteum of the volar distal radius. In 4 of 10 specimens a separate branch to the distal radioulnar joint was present. We found an average PIN diameter of 0.87 mm. CONCLUSIONS: Resection of the AIN at a point 4 cm proximal to the proximal point of the ulnar head would denervate completely the PQ in our cadaver population. Division of the AIN 2 cm proximal to the ulnar head would spare most of the PQ motor branches.     

Surgical treatment of painful neuroma in medial antebrachial cutaneous nerve

The branches of the medial antebrachial cutaneous nerve (MACN) are located at the medial site of the elbow. The MACN, especially the posterior branches, may be injured or transected during cubital tunnel surgery or other medial approaches to the elbow. Damage to the nerve can cause a neuroma, which leads to disabling pain and restriction of elbow movement. The initial treatment of the neuroma is nonsurgical, and includes local massage, desensitization, physiotherapy, and systemic medication. If after 6 months of these nonsurgical treatments there is no improvement, surgery is indicated. The authors report their experience with 12 patients treated surgically for painful neuroma by high resection of the proximal end or its implantation into the triceps muscle. After surgery there was a high success rate of pain relief and functional improvement in both elbow movement and handgrip strength.