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.     

腕关节神经支配的解剖学研究

目的观察支配腕关节神经的来源、直径、数目及其行径;为去神经支配治疗腕关节疼痛提供解剖学资料。方法对10具20侧福马林固定的上肢标本,在手术显微镜下解剖并观察骨间后神经、前臂外侧皮神经、桡神经浅支、尺神经腕背支支配腕关节背侧的腕关节支;骨间前神经、正中神经掌皮支、尺神经深支及其主干支配腕关节掌侧的关节支。结果骨间后神经是支配腕关节背侧神经的主要来源;前臂外侧皮神经、桡神经浅支、尺神经腕背支也发支支配腕关节背侧。骨间前神经、正中神经掌皮支、尺神经深支发支参与支配腕关节的掌侧。结论用去神经支配的方法治疗腕关节顽固性疼痛主要适用于腕背侧的疼痛。     

Surgical exposures of the radius and ulna

The forearm contains many muscles, nerves, and vascular structures that change position on forearm rotation. Exposure of the radial shaft is best achieved with the Henry (volar) or Thompson (dorsal) approach. The volar flexor carpi radialis approaches are used increasingly for exposure of the distal radius. Although the dorsal approach is a safe utilitarian option with many applications, its use for managing fracture of the distal radius has waned. Potential complications associated with radial exposure include injury to the superficial branch of the radial nerve, the lateral antebrachial cutaneous nerve, and the cephalic vein. Dorsal and ulnar proximal radial exposures are associated with increased risk of injury to the posterior interosseous nerve. With surgical exposure of the ulna, care is required to avoid injuring the dorsal cutaneous branch of the ulnar nerve.     

Anatomic study of distally based pedicle compound flaps with nutrient vessels of the cutaneous nerves and superficial veins of the forearm

The purpose of this study was to describe the anatomic basis for a distally based neurovenovascular pedicle compound flap, with nutrient vessels of the cutaneous nerves and superficial veins of the forearm. In this study, the origins, branches, and anastomoses of nutrient vessels of the cutaneous nerves and superficial veins of the forearm and their relationships with the blood supply of adjacent muscle, bone, and skin were assessed in 96 adult cadavers by perfusion of red gelatin into the superior limb arteries. The results showed that the nutrient vessels of cutaneous nerves and superficial veins of the forearm were found to have multiple origins, consisting of six longitudinal vascular plexuses and one transverse vascular plexus of the forearm, as follows: 1) the anterior-lateral vascular plexus from cutaneous branches of the radial artery; 2) the anterior-medialis vascular plexus from cutaneous branches of the ulnar artery; 3) the dorso-lateral vascular plexus from radial osteal and cutaneous branches; 4) the dorso-medialis vascular plexus from ulnar osteal and cutaneous branches; 5) the radial vascular plexus from osteal and cutaneous branches of the radial artery, cutaneous branches of the radial artery in the upper wrist, recurrent branches of the styloid process of the radius, and the radialis vascular plexus of cutaneous branches of the tabatière anatomique (anatomical snuffbox); and 6) the ulnar lateral vascular plexus from cutaneous branches of the ulnar artery in the upper wrist and osteal and cutaneous branches. The transverse vascular plexus is composed of dorsal branches of the ulnar and radial arteries. These perforating branches give fascial branches, cutaneous branches, periosteal branches, and nutrient vessels of cutaneous nerves and superficial veins. These results suggest that nutrient vessels of the cutaneous nerves and superficial veins of the forearm have the same origins as those of the nutrient vessels of adjacent muscles, bones, and skin of the forearm, which can be designated as five types of distally based pedicle flaps with nutrient vessels of cutaneous nerves and superficial veins of the forearm, whose rotation point is at the wrist joint. This flap can be applied to repair tissues of distal parts of the hand.     

The dorsal cutaneous branch of the ulnar nerve. An anatomic clarification with six case reports

We studied the anatomy and pathology of the dorsal cutaneous branch of the ulnar nerve by dissecting 10 fresh cadaver upper limbs and reviewing 6 cases of injury or entrapment of the dorsal cutaneous branch of the ulnar nerve. In all of the cadavers and in our series of cases, several anatomical features were apparent: 1) the dorsal cutaneous branch of the ulnar nerve arises from the main ulnar nerve an average of 5.5 centimeters proximal to the head of the ulna; 2) the dorsal cutaneous branch of the ulnar nerve reaches the dorsum of the hand after coursing volar to the ulnar head; 3) there was no communication between the dorsal cutaneous branch of the ulnar nerve and the superficial sensory branch of the radial nerve; and 4) no volar branches were noted. Based on our experience, disorders of this nerve are more prevalent than previously reported. This clarification of the anatomy will help prevent unnecessary injury during surgery and will be valuable in the diagnosis of disorders of the dorsal cutaneous branch of the ulnar nerve.     

Anatomic variations in sensory innervation of the hand and digits

Anatomic dissections under microscopic magnification were performed on 30 fresh cadaveric hands to depict the course and interconnections of the sensory nerves to the digits. The dissections included the median nerve, the ulnar nerve, the superficial branch of the radial nerve, the dorsal branch of the ulnar nerve, and the dorsal branch of the proper digital nerve. The communicating branches between the median and ulnar nerves in the palm were found in 20 of the 30 (67%) specimens. The dorsal branch of the proper digital nerve was found to arise at or proximal to the A1 pulley zone in 62% of the long digits, more proximally than previously reported. The dorsal sensory nerves (the terminal branch of radial or ulnar sensory nerves) extending to the nail bed area were found in 46% of the digits, thus confirming that sensory supply to the dorsum of the distal phalanx and nail bed also arises from the dorsal sensory nerves. Four types of palmar-dorsal interconnections, located in the middle of the proximal phalanx, were found in the digits but not in the thumb. The presence of these branches indicates dual innervation of the dorsal and palmar side of the distal areas of the digits. These anatomic findings may help hand surgeons interpret discrepancies in sensory loss after either dorsal or palmar injuries.     

皮神经营养血管逆行皮瓣修复手部创面术后并发症的防治

目的 探讨手部皮神经营养血管逆行皮瓣术后并发症的防治.方法 对83例手指和手掌、背创面,采用六种皮神经为轴线设计的皮神经营养血管逆行皮瓣进行修复.其中指神经背侧支皮瓣16例;指背皮神经皮瓣6例;桡神经浅支,包括拇指桡或尺背侧皮神经皮瓣42例;尺神经手背支皮瓣10例;前臂内侧或外侧皮神经皮瓣9例.在皮瓣设计、切取、转移和术后处理方面采取了一系列综合措施防治术后并发症的发生.结果 术后全部皮瓣均存活,但在随访中发现皮瓣供、受区均存在不同程度的并发症:如受区皮瓣静脉回流障碍,皮瓣或蒂部臃肿;供区存有植皮区失活,伤口瘢痕增生,神经瘤形成或虎口轻度挛缩.通过后期注重对皮瓣和蒂部无张力的缝合、皮瓣二期整形等综合措施,有效地降低了并发症的发生.结论 加强皮神经营养血管皮瓣转移术各个环节的精细操作,尽可能矫正皮瓣对手部美观造成的负面影响.才能降低该类皮瓣修复手部创面的术后并发症,提高患者的满意度.     

Sensory communication of the median and ulnar nerves in the palm

A communicating branch between the median and superficial ulnar nerve in the palm of the hand has been described, but its relationship to the cutaneous anatomy of the hand has had little emphasis. Fifty preserved cadaveric hands were dissected. A communicating branch was found in 37 of 50 specimens. In 34 specimens, the connecting branch proceeded from the ulnar nerve to enter the median nerve distally; in three specimens it proceeded from the median nerve to reach the ulnar nerve distally. This study describes the communicating branch in relation to the distal crease of the wrist with the axis of the third webspace and fifth ray as the radial and ulnar borders, respectively. This study may aid surgeons in determining the likelihood of injury in trauma or during various surgical procedures.     

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.     

Surgical Technique in Cadaveric Donors for Partial Hand Allotransplant in Patients With Rheumatoid Arthritis

For patients with severe hand deformities due to rheumatoid arthritis, we propose an allotransplantation of an osteomyotendinose structure (OMTS), preserving the recipient's skin and sensory nerves. Our objective was to develop the surgical technique in a 10 cadavers, five as donors and five as recipients. The donor's hand was 10% to 15% smaller than the recipient's. Dissections were performed by two surgical teams under magnification. In the donor, the OMTS was procured at the distal third of the forearm, maintaining the integrity of the arterial system, with its concomitant veins and motor branches of the median and ulnar nerves, leaving the skin envelope. In the recipient, the OMTS was removed, taking care to preserve the cutaneous cover with the digital arteries in continuity with the superficial palmar arch and radial and ulnar arteries. Also, the digital nerves were maintained in the skin flap, in continuity with the median and ulnar nerves. Their motor branches were divided after emergence from the main nerves. The superficial dorsal veins and radial nerve were kept adhered to the cutaneous cover. Then, the donor OMTS was placed within the recipient cutaneous flap; all the anatomic structures were repaired. The average surgical time was 780 minutes. Methylene blue was present in the digital arteries. There were no difficulties in the anatomic repair. The surgical technique is quite laborious, especially the dissection of the recipient interdigital spaces. Due to the requirement for arterial system integrity, the cutaneous flap must be viable. Also, the allotransplanted OMTS has all necessary conditions to obtain good tissue perfusion for subsequent function. Procurement without skin permits a greater opportunity to find donors, and greater social and personal acceptance by the recipient.     

Ultrasound examination of peripheral nerves in the forearm

BACKGROUND AND OBJECTIVES: We examined in a volunteer population whether nerves in the forearm could be seen consistently using ultrasound imaging and whether this new information could have implications for the way we perform regional anesthesia of the median, radial, and ulnar nerves. METHODS: Eleven volunteers underwent ultrasound examination of both forearms. The median, ulnar, and radial nerves were followed and images were obtained at the elbow, proximal forearm, mid forearm, distal forearm and wrist levels. In addition the radial nerve was followed proximally to a point 5 cm above the elbow. Images were compared for consistency of location of the nerves and depth from skin and width was calculated for each nerve at each level. RESULTS: Anatomy of each nerve was consistent except for one forearm where the median nerve was lateral to the brachial artery at the elbow and one forearm where a superficial ulnar artery only joined the ulnar nerve at the wrist. A convenient location for blockade of both median and ulnar nerves is the midforearm combining ease of visualization, ability to block all terminal branches and minimal potential for vascular injury. The radial nerve is seen most easily at the elbow although blockade of the superficial radial nerve may spare radial motor function. CONCLUSIONS: Nerves in the forearm are consistently located using ultrasound. Further confirmation in clinical practice is required.     

皮神经营养血管皮瓣在手和足软组织缺损中的应用

目的　应用皮神经营养血管蒂逆行岛状皮瓣修复手和足踝部的软组织缺损。方法　以前臂外侧皮神经、桡神经浅支和腓肠神经为轴线 ,分别根据手或足踝部受区大小、部位及供、受区距离设计出逆行岛状皮瓣。结果　腓肠神经营养血管皮瓣修复足踝部创面 4例 ,前臂外侧皮神经营养血管皮瓣修复虎口部创面 1例 ,桡神经浅支营养血管皮瓣修复拇指软组织撕脱伤 1例 ,皮瓣全部成活。结论　根据皮神经营养血管与皮肤血管相互交通的关系设计出的皮神经营养血管皮瓣 ,为手和足踝部软组织缺损的修复提供了血供可靠、简便快捷的新方法     

女性乳房神经分布解剖研究

目的：研究乳房的神经来源、走向及分布,为乳房整形美容手术提供依据,方法：对7具尸体13例乳房进行大体与显微解剖,并对乳头乳晕区神经分布进行组织学研究。结果：第2－6肋间神经的外侧皮支与前皮以都到达并支配乳房,未发现锁骨上神经分支到达乳房。肋间神经支分深、浅两支进入乳房、,走向呈“立体发散”模式到达乳房腺体及皮肤。乳头和乳晕区的神经主要来自于第3－5肋间神经的外侧皮支与前皮支,以第4肋间神经占主导地位,有少量神经伴随乳腺导管走行到达乳头。结论：乳房、乳头和乳晕的神经支配丰富且存在个体差异。     

Block of the brachial plexus branches by the humeral route. A prospective study in 503 ambulatory patients. Proposal of a nerve-blocking sequence

BACKGROUND: Brachial plexus is usually approached by the supraclavicular or axillary route. A technique for selective blockade of the branches of the plexus at the humeral canal using electrolocation has recently been proposed. The aim of the present study was to assess the feasibility of this technique in the ambulatory patient and to determine the optimal sequence of nerve-blocking. METHODS: The nerves originating from the brachial plexus were located in the humeral canal, at the junction of the proximal and the middle third of the arm, with a stimulator and blocked using either lidocaine or a mixture of lidocaine and bupivacaine, depending on the anticipated duration of surgery. The minimal stimulating intensity eliciting an adequate response, type of local anaesthetic and injected volume, and time of onset of surgical anaesthesia were collected. RESULTS: The study included 503 consecutive ambulatory patients due to undergo surgery of the elbow, wrist or hand in one year. Suitable anaesthesia was obtained with the humeral blockade in 82.1% of cases. In the remaining 17.9%, an additional block at the elbow was required, mainly for ulnar and median nerves. The onset times of sensory blocks were the longest for the median nerve, similar for the radial and ulnar nerves, shorter for the musculocutaneous nerve and the shortest for the medial brachial and antebrachial cutaneous nerves. The difference was more significant with the lidocaine-bupivacaine mixture, than with lidocaine alone (P<0.001 vs P<0.05, respectively). The onset times of motor blocks were the longest for the median nerve (P<0.05) and the shortest for the musculocutaneous nerve (P<0.001). Neither nervous nor vascular complications occurred. CONCLUSION: This study shows that the nerve block at the humeral canal is an efficient and safe technique. Considering the onset times of nerve blocks, the following sequence for blockade can be recommended: median, ulnar, radial, musculocutaneous, medial (brachial and antebrachial) cutaneous nerves. The selective blockade of the main nerves of the upper limb at the humeral canal can be recommended for surgery of the forearm and the hand in the ambulatory patient.     

尺神经腕背支营养血管逆行皮瓣的临床应用

目的探讨应用尺神经腕背支营养血管逆行皮瓣修复小指皮肤缺损的临床效果及手术操作要点。方法以尺神经腕背支营养血管远端为蒂,选择小指尺侧分支为皮瓣轴心血管,将皮瓣向小指远端转移,修复小指掌背侧皮肤缺损8例。结果8例全部成活,其中1例因创面止血不彻底,皮瓣受压导致远端部分坏死,经换药后痊愈。结论尺神经腕背支走向较恒定,本组未发现变异。沿皮神经干有纵行的皮神经旁血管网及皮神经干内血管网,此皮瓣血供可靠的,皮瓣切取容易,对供区影响小,是修复小指皮肤缺损的理想方法。     

The nerve supply of the trapeziometacarpal joint

Ten forearm and hand specimens from fresh cadavers were dissected and examined under magnification for articular branches to the trapeziometacarpal joint arising from the thenar and palmar cutaneous branches of the median nerve, the superficial branch of the radial nerve and the lateral cutaneous nerve of forearm. In all but one specimen the thenar branch of the median nerve sent an articular branch to the trapeziometacarpal joint. Multiple branches from the palmar cutaneous branch of the median nerve, the superficial branch of the radial nerve and the lateral cutaneous nerve of forearm were also found. All these branches need to be divided during a "complete" denervation of the trapeziometacarpal joint.     

尺神经手背支卡压所致腕尺侧痛的解剖和临床研究

目的 对尺神经手背支卡压引起腕尺侧痛的机理进行研究并探讨尺神经手背支卡压症的诊断和治疗。方法 对40侧福尔马林固定的成人尸体前臂部和腕部进行大体解剖和显微解剖。在临床上诊治了13例尺神经手背支卡压的病例并进行分析。结果 尺神经手背支在尺骨茎突以近5.6-6.8cm处尺侧腕屈肌（腱）深面内侧缘穿出,紧贴尺骨行走,在尺骨小头内侧分成2－3大支,其中的横支紧贴骨膜,横跨尺骨小头或绕经尺骨小头远端斜行向桡侧,腕关节活动和尺骨小头的位置改变极易对其造成损伤。临床发现患该症的患者尺骨小头远端或尺侧缘有一显著而局限的压痛点,其周围有局部的皮肤感觉改变。13个病例中,7例局部封闭,6例手术,其中9例随访4个月－1年,未见复发。结论 腕关节反复屈伸时尺神经手背支尤其是横支被牵拉和压迫是造成尺神经手背支卡压的解剖学基础。临床上对腕尺侧痛并有皮肤感觉改变的病例,应考虑尺神经手背支卡压的可能性。     

带神经的双侧胸脐皮瓣修复全手皮肤撕脱伤

目的 探讨全手皮肤撕脱伤的治疗方法。方法 采用带神经的双侧胸脐皮瓣修复全手皮肤撕脱伤、右侧皮瓣上的两根神经分别与手掌第1、第3指掌侧总神经吻合，左侧皮瓣上的两根神经分别与尺神经手背支和桡神经皮支吻合。结果 两例全部成功。随访12～15个月，患手有温度觉和触痛觉，尺侧接触台面时有敏感性触觉，且恢复部分握捏功能。结论 带神经双侧胸脐皮瓣修复全手皮肤撕脱伤是一种较好的方法，可在各级医院推广使用。     

The superficial branch of the radial nerve: An anatomic study with surgical implications

Twenty fresh cadaver extremities were dissected to delineate and quantify the course of the superficial branch of the radial nerve. This branch bifurcated from the radial nerve at the level of the lateral humeral epicondyle in eight specimens, and in all specimens the bifurcation was no more than 2.1 cm from the lateral epicondyle. It continued distally, deep to the brachioradialis and became subcutaneous a mean of 9.0 cm proximal to the radial styloid, traversing between the tendons of the brachioradialis and extensor carpi radialis longus. The superficial branch of the radial nerve branched a mean of 5.1 cm proximal to the radial styloid. Distally, at the level of the extensor retinaculum, the closest branches to the center of the first dorsal compartment and to Lister's tubercle were mean distances of 0.4 and 1.6 cm, respectively. In the hand, the superficial branch of the radial nerve most commonly supplied branches to the thumb, the index finger, and the dorsoradial aspect of the long finger. Knowledge of the course of the superficial branch of the radial nerve will help prevent injury during operative procedures on the radial side of the hand, wrist, and forearm and will aid in its localization in treatment of traumatic injuries or performance of nerve blocks in its distribution.     

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.