Susceptibility of the superficial sensory branch of the radial nerve to form painful neuromas

The superficial sensory branch of the radial nerve appears prone to develop painful neuromas out of proportion to its likelihood for injury. Based on cadaver dissections and intraoperative observations, an anatomical mechanism for this "predisposition" is suggested. Exit of this nerve beneath dense fascia and the tendons of brachioradialis and extensor carpi radialis longus provide a proximal tethering against which tension develops as the distal fixation point (neuroma) is pulled through the long excursion of wrist arc of motion. This long excursion and proximal tethering are not present anatomically for the dorsal cutaneous branch of the ulnar nerve nor the palmar cutaneous branch of the median nerve.     

Entrapment neuropathy of the palmar cutaneous branch of the median nerve by the fascia of flexor digitorum superficialis

A case of thenar numbness, with concomitant carpal tunnel syndrome is presented. Physical findings and the result of injection of a local anesthetic into two different sites of tenderness suggested coexistence of entrapment and/or compression of the palmar cutaneous branch of the median nerve and the main trunk of the median nerve at the carpal tunnel. At operation, constriction of the palmar cutaneous branch of the median nerve by the fascia of seemingly normal flexor digitorum superficialis was observed beneath the site of maximum tenderness. After decompression of this nerve, combined with carpal tunnel release, the patient lost all pain and numbness; there was no recurrence at 5 months follow-up.     

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。     

Recurrent neuroma formation after lateral arm free flap coverage with neurorraphy to the posteroantebrachial nerve.

We report a patient with previous wrist trauma and development of a symptomatic neuroma of the palmar cutaneous branch of the median nerve. The patient had previously been successfully treated with lateral arm free flap coverage with neurorrhaphy to a segment of the posteroantebrachial cutaneous nerve carried with the flap. Two years following this procedure the patient experienced re-onset of symptoms prompting surgical exploration of the area. At the time of operation a recurrent neuroma was found at the free distal terminus of the transferred posteroantebrachial cutaneous nerve. The neuroma was repositioned into the distal radius via a burr hole with relief of symptoms.     

Isolated compression neuropathy of the palmar cutaneous branch of the median nerve

A case of isolated thenar numbness, with an associated painful palmar wrist mass is presented. At operation, a palmar wrist ganglion compressing the palmar cutaneous branch of the median nerve was encountered. After ganglion excision the numbness in the palm was relieved, and there was no recurrence at 6 years follow-up.     

Palmar cutaneous branch of the median nerve

The palmar cutaneous branch of the median nerve was dissected in 25 fresh cadavers. The origin from the median nerve, the course, termination, and variability of the palmar cutaneous nerve are described in relation to two reference lines. In no case did a branch of the palmar cutaneous nerve extend ulnar to the axial line of the ring finger. The planning of incisions around the palmar aspect of the palm and wrist should be based on this anatomical knowledge.     

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.     

Nerve fibre composition of the palmar cutaneous branch of the median nerve and clinical implications.

Fifteen fresh human cadaver hands were dissected, using x2.8 loupe magnification, to study the subcutaneous innervation at the site of the incision (in the line with the radial border of the ring finger) for standard open carpal tunnel decompression. Subcutaneous nerve branches were detected and traced proximally to determine their origin. Morphometric analysis of nerve cross sections from the site of the incision and from the main nerve trunk proximal to cutaneous arborisation was performed using light and transmission electron microscopy and a computer-based image analysis system. At the site of the incision, the ulnar sub-branch (US) of the palmar cutaneous branch of the median nerve (PCBMN), which innervates the skin over the hypothenar eminence, was found in 10 of 15 cases. Branches from the ulnar side were not detected. The main trunk of PCBMN consisted on average of 1000 (SD 229) myelinated axons arranged in 1-4 fascicles. In the US of the PCBMN there were on average 620 (SD 220) myelinated axons, 80% of them smaller than 40 microm(2) i.e. thin myelinated axons, and on average 2037 (SD 1106) unmyelinated axons, arranged in 1-3 fascicles. The ratio of the number of myelinated axons in the US and the main trunk of the PCBMN was on average 63% (SD 19%). Frequency distribution of cross-sectional areas of myelinated axons shows no significant difference between the US and the main nerve trunk of the PCBMN. The importance of incision trauma to subcutaneous innervation of palmar triangle is emphasised and possible mechanisms of scar discomfort are discussed.     

正中神经掌皮支营养血管远端蒂肌皮复合瓣解剖学研究及临床应用

目的 探讨正中神经掌皮支营养血管肌皮瓣转移术修复拇指组织缺损的解剖学依据及临床效果.方法 对30侧成人尸体手标本进行解剖,系统观测正中神经掌皮支营养血管链的组成、分支、分布及其同大鱼际肌相互交通吻合的情况.2007年2月以来,临床应用正中神经掌皮支营养血管远端蒂肌皮瓣转移术修复拇指组织缺损17例.结果 桡动脉掌浅支恒定地向拇短展肌和拇短屈肌发出3～5支肌皮穿支,节段性参与正中神经掌皮支营养血管链,肌皮穿支平均外径为[(0.3±0.1)mm,x±s,下同],均有1条静脉伴行.17例术后肌皮瓣全部存活,拇指外观及功能满意,11例患者在术后1周皮瓣两点分辨觉为(6.1～8.2)mm.结论 正中神经掌皮支营养血管链同拇短展肌和拇短屈肌肌皮穿支恒定吻合,该肌皮瓣是修复拇指组织缺损的良好供区.     

Entrapment neuropathy of the palmar cutaneous branch of the median nerve concomitant with carpal tunnel syndrome: a case report

A case of the entrapment neuropathy of the palmar cutaneous branch of the median nerve, concomitant with carpal tunnel syndrome is presented. This report demonstrates that the Semmes-Weinstein monofilament test and nerve conduction studies can identify entrapment of the palmar cutaneous branch of the median nerve concomitant with carpal tunnel syndrome.     

Carpal tunnel release under local anesthesia: evaluation of the outpatient procedure

In 100 consecutive cases of carpal tunnel release done under local anesthesia in an outpatient ambulatory care operating room, 93 had satisfactory results at 6 months without any complications. Two patients developed a neuroma of the palmar cutaneous branch of the median nerve, and five showed early signs of reflex sympathetic dystrophy. These complications are discussed, as well as the prevention of other complications of this procedure.     

Anomalous palmar cutaneous branch of the median nerve in the distal forearm: case report

Variations exist in the anatomy of the palmar cutaneous branch of the median nerve about the wrist. We report an anatomic variation in the course of the palmar cutaneous branch of the median nerve identified in a 17-year-old girl undergoing surgery for a scaphoid nonunion. Instead of coursing ulnar to the flexor carpi radialis tendon, deep to the antebrachial fascia between the tendons of the flexor carpi radialis and palmaris longus, the palmar cutaneous branch of the median nerve was noted to cross volar to the distal aspect of the flexor carpi radialis to lie on its radial aspect. Knowledge of the anatomic variant described in this report should encourage surgeons to dissect carefully as they expose the flexor carpi radialis during the exposure of the distal radius or scaphoid.     

腕部正中神经掌皮支卡压综合征

目的介绍腕部正中神经掌皮支卡压综合征的临床表现,提高对该病的认识水平和治疗效果。方法对２具新鲜尸体和６例手外伤的正中神经掌皮支来源、走行及分支进行解剖和观测,并采用药物封闭治疗。结果正中神经掌皮支在腕横韧带及手掌位置表浅固定,在穿出手掌固有筋膜前有不同程度的膨大。对１９９５年～１９９８年收治的１２例,随访４～１２个月,症状均消失无复发。结论正中神经掌皮支卡压的病因与局部解剖因素有关。其诊断依据主要为腕手掌疼痛,鱼际区皮肤感觉障碍,但无肌肉萎缩。封闭治疗效果好。     

First carpometacarpal joint denervation: anatomy and surgical technique

The main goal of first carpometacarpal arthritis surgery is to relieve pain. The main disadvantage of the classic techniques (trapeziectomy, implant arthroplasty) is that they are extensive surgeries with potential complications, such as radial nerve paresthesia and synovitis. In the author's opinion, denervation of the first carpometacarpal joint is a viable option in selected cases. He describes the technique of denervation based on his previous anatomic investigations. Two incisions are needed to sever all the articular branches derived from the superficial branch of the radial nerve, the palmar cutaneous branch of the median nerve, the thenar branch of the median nerve, and the lateral antebrachial cutaneous nerve. Results comparable with trapeziectomy or first carpometacarpal joint fusion are obtained concerning pain. Complications are uncommon, except for temporary paresthesia of the radial nerve sensory branch.     

正中神经掌皮支营养血管复合组织瓣临床应用

目的：探讨正中神经掌皮支营养血管肌皮瓣转移修复拇指软组织缺损的临床疗效。方法应用正中神经掌皮支营养血管远端蒂肌皮瓣转移修复拇指软组织缺损12例。结果术后12例肌皮瓣全部成活。拇指外观及功能满意,10例在术后1周皮瓣两点分辨觉为6.4～8.7 mm。结论正中神经掌皮支营养血管链同拇短展肌和拇短屈肌肌皮穿支恒定吻合,该肌皮瓣是修复拇指软组织缺损的良好供区。     

The cadaveric anatomy of the distal radius: implications for the use of volar plates

INTRODUCTION

Fractures of the distal radius are common upper limb injuries, representing a substantial proportion of the trauma workload in orthopaedic units. With ever increasing advancements in implant technology, operative intervention is becoming more frequent. As growing numbers of surgeons are performing operative fixation of distal radial fractures, an accurate understanding of the relevant surgical anatomy is paramount. The flexor carpi radialis (FCR) tendon forms the cornerstone of the Henry approach to the volar cortex of the distal radius. A number of key neurovascular structures around the wrist are potentially at risk during this approach, especially when the FCR is mobilised and placed under retractors.

METHODS

In order to clarify the safe margins of the FCR approach, ten fresh frozen human cadaver limbs were dissected. The location of the radial artery, the median nerve, the palmar cutaneous branch of the median nerve and the superficial branch nerve were measured with respect to the FCR tendon. Measurements were taken on a centre-to-centre basis in the coronal plane at the watershed level. In addition, the distances between the tendons of brachioradialis, abductor pollicis longus and flexor pollicis longus, and the radial artery and median nerve were measured to create a complete picture of the anatomy of the FCR approach to the distal radius.

RESULTS

The structure most at risk was the palmar cutaneous branch of the median nerve. It was located on average 3.4mm from the FCR tendon. The radial artery and the main trunk of the median nerve were located 7.8mm and 8.9mm from the tendon. The superficial branch of the radial nerve was 24.4mm from the FCR tendon and 11.1mm from the brachioradialis tendon.

CONCLUSIONS

Operative intervention is not without complication. We believe a more accurate understanding of the surgical anatomy is key to the prevention of neurovascular damage arising from the surgical management of distal radial fractures.     

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.     

A case of neurofibroma of the palmar cutaneous branch of the median nerve

This case report describes a previously unreported entity, a neurofibroma of the palmar cutaneous branch of the median nerve. The lesion presented as a palmar mass with an overlying abnormality of the skin. Treatment consisted of excision of the lesion. Infiltration of the terminal branches of the nerve by the tumour prevented nerve reconstruction but provided a previously unknown diagnostic clue: fibrosis of an area of skin innervated by the involved nerve, which had the appearance of a callosity.     

Painful neuroma of the posterior cutaneous nerve of the forearm after surgery for lateral humeral epicondylitis

PURPOSE: To describe a neuroma of the posterior cutaneous nerve of the forearm that can be the source of pain after surgery for lateral humeral epicondylitis. METHODS: A retrospective chart review of 9 patients having pain after surgery for lateral humeral epicondylitis was conducted to evaluate their history of pain, surgical findings during exploration of their painful lateral elbow scar, and outcome of their surgical treatment. RESULTS: In each of the 9 patients a neuroma of the posterior cutaneous nerve of the forearm was found to be within the scar of the original lateral epicondylitis surgery. For each of these patients the surgical treatment included resection of the neuroma and implantation of the proximal end of the nerve into the brachioradialis muscle proximal to the elbow joint. With this approach 8 of the patients had excellent pain relief and 1 had good pain relief at a mean follow-up time of 1.4 years (range, 1.0-2.6 years). CONCLUSIONS: Pain in the region of the scar after surgery to treat lateral humeral epicondylitis can be caused by a neuroma of the posterior cutaneous nerve of the forearm and this painful neuroma can be treated successfully by neuroma resection and implantation of the nerve proximally into the brachioradialis muscle.     

The surgical anatomy of the dorsomedial cutaneous nerve of the hallux

Most techniques described for the correction of hallux valgus require exposure of the distal aspect of the first metatarsal. A dorsomedial incision is often recommended. Texts counsel against damaging the dorsal digital nerve, as a painful neuroma is an unwelcome surgical complication. Our study on cadavers aimed to investigate the anatomy of the dorsomedial cutaneous nerve in the metatarsophalangeal region, with special reference to surgical incisions. A constant, previously unrecognised branch of the nerve was identified. This branch is likely to be damaged if a dorsomedial approach is used. It is recommended that a mid-medial incision be used instead, i.e. at the junction of the plantar and dorsal skin.