Anatomical Course of the Superficial Branch of the Radial Nerve and Clinical Significance for Surgical Approaches in the Distal Forearm

Abstract 10 embalmed cadaver forearms and wrists were dissected to determine the anatomical course of the superficial branch of the radial nerve in the distal forearm. The superficial radial nerve bifurcated in two branches at a mean of 54,7 mm proximal to the radial styloid. From the styloid process of the radius, the mean distance to the closest dorsal branch of the superficial radial nerve was 3,5 mm and the mean distance to the closest volar branch was 9,8 mm. The mean distance between the closest branch of the superficial radial nerve and Lister?s tubercle was 16,4 mm. The crossing point between the nerve and the cephalic vein was located at a mean of 54,3 mm proximal to the styloid process. At the level of styloid process the mean distance between the closest dorsal branch of the superficial radial nerve and the first dorsal compartment was 15,2 mm and between the closest volar branch and the first dorsal compartment 4,4 mm. Detailed knowledge of anatomic characteristics of the superficial branch of the radial nerve may help prevent injury during operations and treat traumatic lesions of the nerve. Because of great variations in the course of the superficial radial nerve we could not define an absolute safe zone for surgical procedures on the distal forearm. Iatrogenic lesions of the superficial radial nerve are described complications of percutaneous procedures. Therefore open surgical approaches are recommended. Daniela Klitscher and Lars Peter Müller contributed equally to this work.     

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。     

Reconstruction of an amputated fingertip by a prefabricated free volar forearm flap.

An amputated fingertip was banked temporarily under the skin of the volar wrist. This prefabricated fingertip was transferred back to the finger 2 months later, together with a free flap from the volar wrist based on the superficial palmar branch of the radial artery. The fingertip pulp showed a little pale pigmentation, but maintained its length well. The dorsal tip of the finger looked normal. This two-stage procedure made it possible to salvage the amputated bone and nail.     

Results and complications in dorsal and volar wrist Ganglia arthroscopic resection.

The authors present the procedure and results of five years of arthroscopic treatment of wrist radiocarpal and midcarpal ganglia. Thirty cases of dorsal ganglia and seventeen cases of volar ganglia were operated on arthroscopically. The technique was easy to perform in all the radiocarpal ganglia, not easy in midcarpal dorsal ganglia and very difficult in midcarpal volar ganglia. The results were recorded with a mean follow-up of 15 months. Twenty-seven cases of dorsal ganglia and twelve cases of volar ganglia had excellent results with active motion recovery, no complications, absence of scars and no recurrence. Two cases had a recurrence. There were four complications: a case of injury of a radial artery branch, a case of extensive haematoma, and two cases of neuropraxia. In three cases the procedure was converted into open surgery: they had a longer time of healing and a residual scar. The arthroscopic resection has been in our experience effective and safe for the treatment of all radiocarpal ganglia. Good results have been obtained also in the treatment of dorsal midcarpal ganglia. Concerning the uncommon cases of volar midcarpal (STT) ganglia, an open approach seems still indicated.     

腕关节镜掌侧入路的实验与临床研究

目的 报告腕关节镜掌侧入路的设计及初步应用结果.方法 腕关节镜掌桡侧入路定位在桡侧腕屈肌腱桡侧与舟骨结节交界处,掌尺侧入路定位在尺侧腕屈肌腱的尺侧缘、豌豆骨近侧0.5 cm处.对20具防腐腕关节以上离断标本进行解剖学研究,5具新鲜腕关节以上离断标本进行模拟镜下手术.2004年4月至2008年1月,共进行腕关节镜掌侧入路手术20例.男8例,女12例;年龄21～64岁,平均35.6岁.结果 掌侧入路与其周围的血管、神经等结构均有一定的安全距离.掌侧入路镜检可以清晰显示背侧关节囊、舟月骨间韧带的掌侧部分和月三角骨间韧带的掌侧部分.通过掌侧入路置入关节镜,背侧入路置入手术器械,可以更方便地处理腕关节腔背侧部分的病变.20例临床病例均未发生并发症,平均随访23.4(12～37)个月.末次随访时,腕关节背伸-掌屈活动度为134°±16°,桡尺偏活动度为39°±8°,旋前-旋后活动度为139°±18°.术前有2例疼痛为Ⅱ级,18例疼痛为Ⅲ级;末次随访时,11例疼痛为Ⅰ级,8例为Ⅱ级,1例为Ⅲ级;疼痛缓解显著(Z=31.2,P＜0.01).改良Garland和Werley评分为:优10例,良6例,可4例,优良率为80%.结论 腕关节镜掌侧入路是传统背侧入路的重要补充,具有安全性高、操作方便的优点.     

The volar wrist ganglion: just a simple cyst?

The results of operation on 71 volar wrist ganglia are reported. The recurrence rate was 28%, occurring between 1 and 144 months (median: 5 months). The highest risk of recurrence is in a male patient, under 30 years of age, in a manual occupation, operated on by a junior surgeon. The use of a post-operative plaster slab seemed to be followed by significant wrist stiffness. 28% of the patients had evidence of damage to the palmar cutaneous branch of the median nerve. It is suggested that this could be avoided by positive identification of this nerve at operation.     

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.     

Aberrant course of a communicating branch of the ulnar nerve to the median nerve contributing to hypothenar Hammer syndrome

This presentation represents a unique anatomic predisposition to the development of hypothenar hammer syndrome (HHS). In this case, a communicating branch of the ulnar nerve to the median common digital nerve of the ring finger was identified crossing volar to the superficial palmar arch. This relationship caused thrombosis of the superficial palmar arch proximal to this crossing nerve branch. The aberrant course of this nerve created a structural anomaly contributing to HHS, which ultimately mandated surgical intervention.     

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.     

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 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.     

Preoperative assessment of hand circulation by means of Doppler ultrasonography and the modified Allen test

OBJECTIVE: The aims of this study were as follows: (1) to evaluate Doppler ultrasonography in assessing hand collateral circulation; (2) to define the criteria for an abnormal Doppler ultrasonography dynamic test result; and (3) to validate the modified Allen test. METHODS: The hand circulation of 71 patients scheduled for coronary artery bypass grafting was assessed by means of the Allen test and Doppler ultrasonography. The flow in the superficial palmar branch of the radial artery, the ulnar artery, and the dorsal digital thumb artery with and without radial artery compression were recorded. Flow patterns in the superficial palmar branch of the radial artery, the ulnar artery, and the dorsal digital thumb artery with radial artery compression were categorized into 4 groups: (1) no flow; (2) decreased flow; (3) reversed flow; and (4) increased flow. RESULTS: Among the 71 hands, 4 (5.6%) had an abnormal Allen test result (>10 seconds). Seven (10.6%) of 66 superficial palmar branches of the radial artery, 3 (4.2%) of 71 ulnar arteries, and 2 (2.8%) of 71 dorsal digital thumb arteries showed no flow with radial artery compression, as measured by Doppler ultrasonography. There were significant differences among the 4 groups (superficial palmar branch of the radial artery: F = 7.0, P <.001; ulnar artery: F = 13.1, P <.001; and dorsal digital thumb artery: F = 8.4, P <.001) for the Allen test. Pairwise comparisons showed that when subjected to an Allen test, category 1 patients (no flow) had significantly longer recovery times compared with the other groups (P <.02 in all cases) for the superficial palmar branch of the radial artery, the ulnar artery, and the dorsal digital thumb artery. CONCLUSION: Absence of flow in the dorsal digital thumb artery with radial artery compression is considered an absolute contraindication to radial artery harvesting. An increased recovery time with the modified Allen test predicts absence of flow in the dorsal digital thumb artery in Doppler ultrasonographic flow patterns. This demonstrates the validity of the modified Allen test for primary screening.     

Late compression neuropathies after Colles' fractures

Conservative management of 166 Colles' fractures was associated with a 12% rate of late compression neuropathies (mean follow-up period, 28 months). Compression of the median nerve (8%) was twice as common as ulnar nerve compression (4%). Eighty-five percent of the patients with median nerve compression had malunion with radial collapse with or without other deformities (dorsal angulation/radial displacement). Patients with ulnar nerve compression had either malunion with radial collapse or volar subluxation of the ulnar head in those fractures that healed with dorsal angulation. Patients without nerve complications showed a significantly lower rate of malunions. These results demonstrate that anatomic derangements play a role in the development of late compression neuropathies following Colles' fractures.     

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.     

桡动脉浅支皮瓣修复手指皮肤缺损

目的：探讨应用桡动脉浅支皮瓣修复手指皮肤缺损的方法及临床疗效。方法2008年8月-2012年1月,采用游离桡动脉浅支皮瓣修复手部皮肤缺损伴骨或肌腱外露30例,以桡动脉浅支走行于腕掌侧设计皮瓣,其中20例于皮瓣近端切取正中神经掌皮支重建感觉。皮肤缺损范围为1.5 cm×2.5 cm～2.0 cm×3.5 cm。结果本组30例皮瓣全部成活,未发生血管危象。术后随访6～12个月,皮瓣质地血运良好,外形满意,两点辨别觉为5～7 mm,供区无并发症。结论游离桡动脉浅支皮瓣切取方便,供区损伤小,是修复手指皮肤缺损较为理想的方法。     

带感觉支指背侧岛状皮瓣的应用解剖学研究

目的 探讨含指掌侧固有神经背侧支的指背岛状皮瓣的应用解剖学，以提高皮瓣的修复疗效。方法 在20具40侧成人上肢标本上解剖观测指掌侧固有神经背侧支的起点和走行。另对4具8侧成人上肢进行血管铸型制作，观察指掌侧固有动脉及手指静脉的分布范围。结果 示、中、环指的指掌侧固有神经在掌指关节附近恒定发出1较大的背侧支，小指尺侧未见背侧支出现；小指桡侧背侧支缺如者占82．5％。指掌侧固有神经背侧支在近节指骨中下1／3处恒定地和指掌侧固有动脉相交，在该处神经跨过动脉上方的占69．17％，另30．83％走行在动脉下方。结论 示、中、环指的背侧支有较为恒定的蒂部，可以包含在指背侧岛状皮瓣中。其体表投影为近节指骨基底掌侧部中外1／3至近侧指问关节背外侧，以及其和甲根外侧缘的连线。小指桡侧的指掌侧固有神经背侧支缺如率较高，不宜设计成背侧支指背皮瓣。     

Arterial patterns of the deep and superficial palmar arches

The vascular patterns of the palmar arches and their interconnecting branches present a complex and challenging area of study. Improvements in microsurgical techniques have made a better understanding of vascular patterns and vessel diameters more important. Forty-five fresh limbs from cadavers were amputated at the level of the midhumerus. Ward's red latex or Batson's compound was injected under pressure to visualize the arterial system in the hand. After hardening of the injected material, the skin, subcutaneous tissues, and tendons were removed. The specimens were digested in concentrated potassium or sodium hydroxide leaving the bony elements and a cast of the arterial system. The superficial palmar arch is most easily classified into two categories: complete or incomplete. An arch is considered to be complete if an anastomosis is found between the vessels constituting it. An incomplete arch has an absence of a communication or anastomosis between the vessels constituting the arch. Complete superficial palmar arches were seen in 84.4% of specimens. In the most common type, the superficial arch was formed by anastomosis between the superficial volar branch of the radial artery and the ulnar artery. This was seen in 35.5% of specimens. In 31.1%, the arch was formed entirely of the ulnar artery. Incomplete superficial arches were seen in 15.5% of specimens. In 11.1%, the ulnar artery forms the superficial arch but does not contribute to the blood supply to the thumb and index finger. The deep palmar arch was found to be less variable with 44.4% formed by an anastomosis between the deep volar branch of the radial artery and the inferior deep branch of the ulnar artery. Injection followed by chemical debridement allows direct visualization and measurement of the arches and the smaller arterial branches that are visualized poorly with other techniques. Based on the vessel measured, vessels of the superficial and deep arches are of sufficient size to allow microvascular repair, although repair of the communicating branches, the dorsal carpal rete, and its branches, probably is not feasible because of their small size.     

Articular ganglia of the volar aspect of the wrist: Arthroscopic resection compared with open excision. A prospective randomised study

Our aim was to compare two methods of treatment of ganglia on the volar aspect of the wrist (the open excision done through a longitudinal volar skin incision and the arthroscopic resection through two or three dorsal ports), to see if arthroscopy could reduce the risks of operating in this area and the time to healing. Twenty radiocarpal and five midcarpal volar ganglia were operated on by open approach and an equivalent group was treated by arthroscopy. Fifteen radiocarpal and five midcarpal ganglia were treated with good results in the open group and 18 radiocarpal and one midcarpal ganglia in the arthroscopic group (no visible or palpable ganglion, a full range of active wrist movement, grip strength equal to preoperatively, no pain, and a cosmetically acceptable scar). In the open group there were four injuries to a branch of the radial artery, two cases of partial stiffness of the wrist associated with a painful scar, one case of neuropraxia, and one recurrence (all of which were among the 20 radiocarpal ganglia). In the arthroscopic group there was one case of neuropraxia, one injury to a branch of the radial artery, and three recurrences (three of the complications were among the five midcarpal ganglia). The mean functional recovery time was equal to 15 (6) days in the open group and 6 (2) days in the arthroscopic group. The mean time lost from work was equal to 23 (11) days in the open group and 10 (5) days in the arthroscopic group. Our results suggest that arthroscopic resection is a reasonable alternative to open excision in treating radiocarpal volar ganglia because it has less postoperative morbidity and a better cosmetic result. Midcarpal volar ganglia, however, should still be treated by open operation.     

Percutaneous fixation of scaphoid fractures. An anatomical study

Percutaneous scaphoid fracture fixation has many advantages over the open method of fixation. We describe the anatomical basis for a safe percutaneous approach. Cannulated screws were inserted into 32 cadaveric scaphoids through 1 cm palmar incisions under fluoroscopic control. We then measured the distance between the entry point in the scaphoid and important local neurovascular structures. We also measured the angle of entry of the guide wire in two planes. The mean distance of the entry point from the main radial artery was 14 mm (range, 7-24 mm); from the radial nerve 19 mm (range, 7-35 mm); from the recurrent branch of the median nerve 29 mm (range, 14-45 mm); and from the superficial branch of the radial artery 5 mm (range, 0-8 mm) The mean radial angle of insertion was 34 degrees and the mean palmar angle of insertion was 58 degrees. Percutaneous fixation of scaphoid fractures puts the superficial palmar branch of the radial artery at risk. We recommend a 1 cm incision centred over the scaphotrapezial joint and dissection under direct vision to the entry point in the scaphoid rather than a completely percutaneous approach.