Internal anatomy of the communicating branch between the ulnar and median nerves in the hand and its relevance to volar digital sensibility.

We studied the microanatomy of the communicating branch between the ulnar and median nerves in 26 adult cadaver hands to explain diminished sensibility in the fourth and fifth fingers we had observed in 2 patients after complete transection of the median nerve. Two new variations of the communicating branch were observed. In the first variation the communicating branch originated proximally from the third common digital nerve to distally join the ring finger ulnar digital nerve and the small finger radial digital nerve. In the second variation the ramus communicans traversed perpendicularly between the third and fourth common digital nerves with a crossover of nerve fibers.     

The surgical anatomy of ulnar and median nerve communications in the palmar surface of the hand

OBJECT: Sensation in the palmar surface of the digits is supplied by the median and ulnar nerves, with the boundary classically being the midline of the ring finger. Overlap and variations of this division exist, and a communicating branch between the ulnar and median nerve could potentially explain further variations in digital sensory innervations. The aim of this study was to examine the origin and distribution of the communicating branch between the ulnar and median nerves and to apply such findings to the risk involved in surgical procedures in the hand. METHODS: The authors grossly and endoscopically examined 200 formalin-fixed adult human hands obtained in 100 cadavers, and a communicating branch was found to be present in 170 hands (85%). Of the specimens with communicating branches, the authors were able to identify four notable types representing different points of connections of the branches. The most common, Type I (143 hands, 84.1%), featured a communicating branch that originated proximally from the ulnar nerve and proceeded distally to join the median nerve. Type II (12 hands, 7.1%) designated a communicating branch that originated proximally from the median nerve and proceeded distally to join the ulnar nerve. Type III (six hands, 3.5%) designated a communicating branch that traversed perpendicularly between the median and ulnar nerves in such a way that it was not possible to determine which nerve served as the point of origin. Type IV (nine hands, 5.3%) designated a mixed type in which multiple communicating branches existed, arising from both ulnar and median nerves. CONCLUSIONS: According to the origin and distribution of these branching patterns, the investigators were able to define a risk area in which the communicating branch(es) may be subject to iatrogenic injury during common hand procedures.     

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 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.     

Digital innervation patterns following median or ulnar nerve laceration and their correlation to anatomic variations of the communicating branch between these nerves

The midline of the ring finger is classically considered as the neural watershed between the median and ulnar nerve sensory territories on the palmar surfaces of the fingers. Variations of this division exist and may be explained by a communicating branch between the third and fourth common digital nerves. The palmar sensibility patterns of fingers were assessed with Semmes Weinstein filaments after either a complete median or an ulnar nerve transection in 43 patients. Eight out of nine observed sensibility patterns could be explained by known anatomic types and subtypes of the communicating branch. The type of communicating branch, but not its subtype, could be established in the one remaining pattern.     

Unusual anatomic variation of palmar sensory branches of the ulnar nerve: a case report.

Variant sensory branches of the ulnar nerve were encountered during a routine dissection of the palmar aspects of a cadaver hand. The variant branches were distributed to the ulnar half of the index, ulnar half of the middle, and radial half of the ring fingers. The communicating branch between the superficial ulnar branch and the third common digital branch of the median nerve was absent. Distribution of the median nerve sensory branches was normal. The clinical significance of this variation is discussed.     

Cutaneous perforators of the fourth dorsal interosseous space: anatomic study

PURPOSE: Many investigators have studied the vascular anatomy of the dorsal metacarpal arteries but little attention has been paid to the exact distribution of the cutaneous perforators of the dorsum of the hand. We present an anatomic study of the cutaneous perforators within the fourth dorsal interosseous space, which was supposed to have the most inconsistent vascular anatomy. METHODS: Twenty hands were dissected after black latex injection. A skin paddle was outlined along the fourth dorsal metacarpal space. Suprafascial dissection was performed, preserving any vessel piercing the fascia and reaching the skin. Each perforator was traced back to its origin. The location and origin of each perforator was recorded by digital pictures and measured from a reference point. RESULTS: In 17 of the cases (85%) at least 1 perforator was identified within the fourth space piercing the dorsal interosseous muscle fascia and reaching the skin. In 10 hands, a perforator branching off the proximal communicating branch was identified, located a mean distance of 11 mm from the carpometacarpal joint line. CONCLUSIONS: A dissectable perforator was found consistently (17 of 20; 85%) in the proximal third of the fourth dorsal interosseous space branching off the proximal communicating branch. Few perforators branch off the middle third of the dorsal metacarpal artery. The perforator described herein shows the connection between the superficial and deep vascular systems of the ring and small metacarpal spaces, and establishes the anatomic basis for reconstructive flaps.     

The anatomy of the Berrettini branch: implications for carpal tunnel release

OBJECT: Dissections were performed in 100 fresh cadaver palms to determine the frequency with which superficial palmar communication between the median and ulnar nerves occurs and to what extent it might incur iatrogenic injury during endoscopic carpal tunnel release. METHODS: Superficial palmar communication between the median and ulnar nerves was present in 81% of the dissected hands. Superficial palmar communication, also known as the Berrettini branch, has been classified into four distinct types by Ferrari and Gilbert. Twelve hands were classified as Group 1 (communication in an oblique course from the ulnar to the median nerve originating >4 mm above the distal margin of the transverse carpal ligament [TCL]), 16 hands were classified as Group 2 (communication parallel to the distal margin of the TCL), and 53 hands were classified as Group 3 (communication in an oblique course from the ulnar nerve to the third common digital nerve, originating below the distal margin of the TCL). No hand fit the Group 4 classification (atypical communication). CONCLUSIONS: The Berrettini branch can be considered a normal anatomical finding. In 28% of the hands in this study, the branch was proximal to the edge of the distal ligament and, therefore, prone to iatrogenic injury in both one-portal and two-portal endoscopic surgery.     

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 septa of Legueu and Juvara: an anatomic study

PURPOSE: To study the anatomy of the septa of Legueu and Juvara and interpalmar plate ligaments (IPPLs) of the hand. MATERIALS: Eleven cadaver hands were dissected. The number, attachments, dimensions, and relationships of the septa and IPPLs to other structures were determined. RESULTS: Eight septa were identified radial and ulnar for each digit. The radial were longer than the ulnar septa. The septa attached to the transverse ligament of the palmar aponeurosis superficially and to the soft-tissue confluence deeper and distally. They formed 7 compartments of 2 types flexor septal canals that contained the flexor tendons and web space canals that contained common digital nerves and arteries and lumbrical muscles. Grossly and histologically the septa were thicker and consisted of organized collagen distally but not proximally. Three IPPLs were identified: radial, central, and ulnar. These formed the floors of the second, third, and fourth web space canals. The IPPLs were more substantial, thicker, and had more fibrous appearance from radial to ulnar. The fibers of the radial and central IPPLs were oriented transversely, whereas those of the ulnar IPPL were oriented obliquely. CONCLUSIONS: Awareness of the anatomy of deep retinacular structures of the hand is important for surgical exposure in this area and possible involvement in conditions such as Dupuytren's disease.     

Recognition of acutely lacerated ulnar nerve-median nerve palmar communicating branch. A case report

A 32-year-old man incurred a porcelain faucet handle laceration to the palm, including the third common digital nerve and an adjacent large communicating sensory ramus to the third common digital nerve from the superficial ulnar nerve. This case is the first reported recognition and repair of a freshly lacerated communicating ramus.     

指固有神经背侧支的应用解剖学研究

目的 为指固有神经背侧支的临床应用提供解剖学基础。方法 观测12只新鲜成人手标本48个手指指固有神经背侧支出的出现率、直径、走向及分支。结果 示、中、环指及小指桡侧指固有神经发出的单一分支形成背侧支者占92．86％（78．84）,背侧支缺如者占7．14％（6．84侧）。各指背侧支均在近节手指近、中1／3平面发出,并从指侧面斜向指背远端走行。在近指间关节桡背（或尺背）侧向背面及中节指背发出2－5条分支。除小指外,2－4指指桡、尺侧背侧支的直径粗细均有显著性差异（P＜0．05）,桡侧＞尺侧。小指飞侧无指固有神经背侧支。结论 示、中、环及小指的桡侧指固有神经背侧支走向恒定,可包含在同指逆行岛状皮瓣内,适用于修复指腹软组织缺损。     

游离足底内侧皮瓣修复腕掌尺侧皮肤神经缺损

目的 探讨修复腕掌尺侧皮肤神经同时缺损的新方法.方法 2000年4月至2009年8月,应用游离足底内侧皮瓣修复腕掌尺侧皮肤并神经缺损5例.足拇趾胫侧趾底固有神经修复小指尺掌侧固有神经缺损1例;桡神经浅支修复尺神经及其深浅支缺损2例,修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例;尺神经手背支修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例.足底内侧血管与尺血管吻合.供区取同侧大腿皮片移植修复.结果 术后皮瓣及移植皮片全部成活.5例获得6个月至4年的随访,皮瓣质地好、外观满意,无手内肌萎缩和爪形手畸形,皮瓣和手指感觉恢复达S3～S3+,皮瓣两点辨距觉为7～10 mm.尺神经深浅支缺损病例术后综合评价均为优.结论 游离足底内侧皮瓣是修复腕掌尺侧皮肤神经缺损的有效方法.     

游离足底内侧皮瓣修复腕掌尺侧皮肤神经缺损

目的 探讨修复腕掌尺侧皮肤神经同时缺损的新方法.方法 2000年4月至2009年8月,应用游离足底内侧皮瓣修复腕掌尺侧皮肤并神经缺损5例.足拇趾胫侧趾底固有神经修复小指尺掌侧固有神经缺损1例;桡神经浅支修复尺神经及其深浅支缺损2例,修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例;尺神经手背支修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例.足底内侧血管与尺血管吻合.供区取同侧大腿皮片移植修复.结果 术后皮瓣及移植皮片全部成活.5例获得6个月至4年的随访,皮瓣质地好、外观满意,无手内肌萎缩和爪形手畸形,皮瓣和手指感觉恢复达S3～S3+,皮瓣两点辨距觉为7～10 mm.尺神经深浅支缺损病例术后综合评价均为优.结论 游离足底内侧皮瓣是修复腕掌尺侧皮肤神经缺损的有效方法.     

游离足底内侧皮瓣修复腕掌尺侧皮肤神经缺损

目的 探讨修复腕掌尺侧皮肤神经同时缺损的新方法.方法 2000年4月至2009年8月,应用游离足底内侧皮瓣修复腕掌尺侧皮肤并神经缺损5例.足拇趾胫侧趾底固有神经修复小指尺掌侧固有神经缺损1例;桡神经浅支修复尺神经及其深浅支缺损2例,修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例;尺神经手背支修复尺神经浅支、第4指掌侧总神经及小指尺掌侧固有神经缺损1例.足底内侧血管与尺血管吻合.供区取同侧大腿皮片移植修复.结果 术后皮瓣及移植皮片全部成活.5例获得6个月至4年的随访,皮瓣质地好、外观满意,无手内肌萎缩和爪形手畸形,皮瓣和手指感觉恢复达S3～S3+,皮瓣两点辨距觉为7～10 mm.尺神经深浅支缺损病例术后综合评价均为优.结论 游离足底内侧皮瓣是修复腕掌尺侧皮肤神经缺损的有效方法.

Abstract：

Objective To explore a new method for repair of concurrent skin and nerve defect at palm and carpal on ulnar side. Methods From April 2000 to August 2009, five cases with concurrent skin and nerve defect at palm and carpal on ulnar side were reconstructed with free medial plantar flaps.Palmar nervous proprii defect at ulnar side of little finger was repaired by the first toe tibia nervous proprii in one case. The superficial branch of radial nerve was applied to repair the defect of ulnar nerve, as well as its deep or superficial branch in two cases. The superficial branch of radial nerve was also used to repair the defect of superficial branch of ulnar nerve, common palmar digital nerve of the fourth finger, Little finger ulnar palmar nervous proprii in one case. The dorsal branch of ulnar nerve was applied to repair the defect of superficial branch of ulnar nerve, common palmar digital nerve of the fourth finger, little finger ulnar palmar nervous proprii in one case. The vascular bundle of medial plantar flap was anastomozised with ulnar vascular bundle. The wounds at donor sites were covered with free skin grafts which were obtained from upper leg. Results All the flaps and skin grafts were survived completely. The five patients were followed up for six months to four years with no muscular atrophy or claw hand deformity. The esthetic result was satisfied. The Sensory of flaps and fingers recovered to S3 to S3+. The two-point discrimination distance on flaps was range from 7 mm to 10 mm. The postoperative comprehensive evaluation was excellent in the cases whose superficial and deep branches of ulnar nerve were repaired.Conclusions Free medial plantar flap is an effective method to repair concurrent skin and nerve defect at palm and carpal on the ulnar side.     

Lateral congenital anomalies of the pharyngeal apparatus: part II. anatomy of the abnormal for the surgeon

"Anatomy of the abnormal"-a branch of surgical anatomy-deals with relations of an anomaly to surrounding entities. Here, lateral congenital anomalies of the pharyngeal apparatus are examined; their relations to entities of the neck can be explained embryologically. Location of embryonic pharyngeal arches, clefts, and pouches in the adult is presented and terminology of these anomalies (fistulas, sinuses, cysts) is defined. First "cleft and pouch" anomalies relate with the parotid and facial nerve. Second cleft and pouch anomalies course deeply to second arch structures and superficially to third arch structures. Consequently, they relate with hypoglossal and glossopharyngeal nerves and internal and external carotid arteries. Third cleft and pouch anomalies pass deep to third arch entities and superficial to those of the fourth arch and relate with glossopharyngeal, hypoglossal, superior and recurrent laryngeal nerves, and the internal carotid artery. The complicated course of fourth cleft and pouch anomalies brings them into relationship with glossopharyngeal, hypoglossal, superior and recurrent nerves, internal carotid, aorta, and subclavian arteries. Found superficially are veins (external and anterior jugular, common facial, communicating), nerves (transverse cervical, great auricular, mandibular, cervical branches of facial), and relevant spinal nerves (e.g., accessory). Knowledge of these anatomical relations helps prevent anatomical complications.     

Anatomic study of variations of hypothenar muscles and arborization patterns of the ulnar nerve in the hand

PURPOSE: To show the variations in the hypothenar muscles and the arborization patterns of the ulnar nerve and to investigate the relationship between the hypothenar muscles and the ulnar nerve. METHODS: We performed an anatomic study of 35 hands from embalmed cadavers. After dissecting the ulnar side of the hand we recorded the number of hypothenar muscles and their variations, the site of the hiatus for the deep branch of the ulnar nerve, and the branching patterns of the ulnar nerve in each hand. We then investigated the relationship between the variations in the hypothenar muscles and the arborization patterns of the ulnar nerve. RESULTS: The abductor digiti minimi (ADM) had 1 belly in 6 hands, 2 bellies in 28 hands, and 3 bellies in 1 hand. The flexor digiti minimi brevis was absent in 8 hands, had 1 belly in 24 hands, and had 2 bellies in 3 hands. The opponens digiti minimi had 2 layers of origin and the deep branch of the ulnar nerve passed between these 2 layers in all hands. We classified the structural patterns of the hiatus into 3 types, the arborization patterns of the ulnar nerve into 5 types, and the branching patterns of the motor branch to the ADM into 4 types according to their morphologic characteristics. We found variations of the arborization pattern in which the deep branch originated from the ulnar trunk of the ulnar nerve distal to bifurcation in 3 hands, a communicating branch was present between the 2 sensory branches to the fingers in 3 hands, and the ulnar sensory branch pierced the ADM in 2 hands. CONCLUSIONS: We confirmed that the anatomic relationship between the ulnar nerve and the hypothenar muscle is complex and that the formation of the hiatus varies. This knowledge can assist the surgeon in the diagnosis and treatment of conditions associated with the ulnar aspect of the hand.     

Safety of carpal tunnel release with a short incision. A cadaver study

The standard long incision technique for carpal tunnel release causes inevitable damage to skin sensation, the inter-thenar plexus and especially the distal branches of the palmar cutaneous branch of the median nerve (PCM), and may cause long-term disabling pain and scar tenderness. There are many variations in the distal branches of the median nerve at the wrist. Anatomic studies of this region also have important clinical implications to prevent injury to important anatomic structures. The purpose of this study was to evaluate the short-incision carpal tunnel release in cadavers. Several important anatomic structures, with possible anatomic variations, pass through the carpal tunnel, and blind percutaneous transection of the transverse ligament seems to be a high risk procedure. Sixty hands from 40 fresh cadavers were evaluated. Both the transverse ligament and the distal third of the deep forearm fascia were released using a Smillie knife. At the end of each procedure, the hand was explored for injury to tendinous and neurovascular structures of the wrist. In all cases the release of the carpal tunnel and the distal third of the forearm fascia was found to be complete. The superficial palmar arterial arch, flexor tendons, ulnar nerve and vessels, digital nerves, median nerve and its recurrent accessory branches, the flexor tendons, and even the subcutaneous tissue over the transverse ligament were damaged in no instance. Guyon's canal was entered in 6 (10%) hands without damage to its components. The distal branches from the ulnar side of the palmar cutaneous branch of the median nerve (PCM) were injured in 8 (13.6%) hands, an injury that is almost unavoidable with the classic open technique.     

Progression of forearm intravenous regional anesthesia with ropivacaine

The progression of sensory blockade in the hand following a forearm Bier block with ropivacaine is currently unknown. The hands of 10 healthy adult human subjects were anesthetized with ropivacaine, and their sensitivities to cold and touch were tested until the completion of anesthesia. On average, insensitivity to cold occurred uniformly throughout the hand within 9 mins; however, touch sensation was not complete until approximately 20 mins after injection. The spread of anesthesia occurred in a semisystematic way, spreading proximally and distally from the site of injection (mid-dorsum of the hand), and, at a slower rate, from the dorsum of the hand to the palm.