Radial nerve cross-finger flap differential nerve contribution in thumb reconstruction

Six patients with extensive palmar thumb pulp and soft tissue loss were treated with a staged transfer of radial nerve innervated flap tissues from the dorsum of the index finger. They were followed for a mean period of 3 years. This transfer of radial nerve innervated dorsal index finger tissues to the palmar surface of the thumb has been a successful method of innervation restoration. The ultimate sensibility of the reconstructed thumb seems to be a mixture of median and radial nerve sensibility. Sensory testing shows that after transfer, the ulnar side of the flap is more innervated from the radial nerve than the radial side. Our findings suggest that the presence of active sensory axons in the radial nerve innervated flap may play an inhibitory role in direct and/or functional neurotization of the transferred flap.     

Evaluation of moving and static two point discriminations of volar forearm skin before and after transfer as a sensate radial forearm island flap in reconstruction of degloving injury of the thumb.

In degloving injury of the thumb the large skin defect needs cover with sensate, glabrous and pliable skin. Although coverage of this defect with a sensate free flap from the foot is the best choice, most commonly, cover is achieved using a non-sensate distant pedicle flap. Between 2001 and 2003, degloving injuries of the thumb in eight patients were reconstructed using a sensate radial forearm flap in the sensory territory of the lateral ante-brachial nerve of the forearm which was repaired to the digital nerve of the thumb (six cases) or to a branch of the sensory radial nerve (two cases). Follow-up period ranged from 17 to 41 months (mean: 29.9 months). Sensory evaluation was performed using the moving two point discrimination (M-2PD) and static two point discrimination (S-2PD) of the volar forearm skin. These altered significantly after transfer and their values approached those of the contra-lateral thumb but never reached normal sensation (p<0.01). Sensate radial forearm island flap is a reliable option to cover a large defect of the thumb such as degloving injury and the sensation produced is acceptable.     

六种皮瓣修复拇指腹缺损的远期疗效观察

目的评价6种皮瓣修复拇指腹缺损的远期疗效.方法对2001年12月前,在我科接受6种皮瓣修复拇指腹缺损（锁骨下带蒂皮瓣、手指掌侧推进皮瓣、示指背侧皮瓣、带血管神经蒂的大鱼际近端皮瓣及趾腹游离皮瓣）共142例患者,进行了远期随访.随访内容有术后拇指腹色泽、外形、质地、出汗情况、拇指的痛觉、触觉、两点分辨觉、综合质地感觉及运动功能等.结果142例均获得了完整资料.6种皮瓣中,其中锁骨下带蒂皮瓣与示指背侧皮瓣修复的拇指腹,从皮肤色泽、外形、质地、出汗情况等均比其它4种皮瓣差,综合质地感觉优良率也明显低于其它4种皮瓣.结论手指掌侧推进皮瓣、指侧方血管蒂岛状皮瓣、带血管神经蒂的大鱼际近端皮瓣及趾腹游离皮瓣修复拇指腹缺损远期临床效果良好,但指侧方血管蒂岛状皮瓣对手部创伤较大,影响患手美观及供区手指的感觉.     

End-to-side neurorrhaphy of sensory nerves

One century passed before end-to-side neurorrhaphy was rediscovered, and now it finds more frequent use in clinical practice. Experimental studies have improved our understanding of the underlying mechanism and its potential. However, still discussed is whether reinnervation by end-to-side neurorrhaphy works as well in sensory nerves as in motor nerves. The digital nerves are sensory nerves and therefore an ideal model to investigate this question. Two cases of successful sensory reinnervation by end-to-side nerve suture are reported. We began to use end-to-side nerve repair clinically in 1995 and have used it for motor or sensory reinnervation in a total of 13 cases. In two patients primary nerve repair using end-to-side neurorrhaphy was performed in digital avulsion injuries. In one patient the avulsed ulnar nerve of the thumb was sutured end-to-side to the median nerve; in the other the ulnar digital nerve of the ring finger had been destroyed over a distance of 20 mm, and the distal stump was joined end-to-side to the radial nerve of the same finger. Sensory recovery was obtained in both patients. The static two-point discrimination was 3.0 mm, and dynamic two-point discrimination was 2-3 mm for the reinnervated finger compared to 2 mm for static and dynamic two-point discrimination in the adjacent "donor" finger. The sensation of the finger supplied by the "donor nerve" was not altered in relation to the corresponding contralateral finger site. Excellent sensory reinnervation is possible through an end-to-side nerve suture. Proximal avulsion, missing proximal nerve stumps, partial recovery, and prevention of nerve grafts are good indications for resensitization using end-to-side neurorrhaphy. No harm to the donor nerve is expected. Preference should be given to donor nerves that supply skin areas near to the anesthetic area.     

Radial sensory neurotization of the thumb and index finger for prehension after proximal median and ulnar nerve injuries

Proximal median nerve injuries are functionally disabling, secondary to both motor and sensory deficits. Reestablishment of sensation relies on slow axonal regeneration originating from the site of injury after either primary nerve repair or the use of autogenous nerve grafts. This regeneration can take 2 or more years to restore sensation to the hand, depending on injury location. Distal sensory nerve transfers shorten the recovery time by decreasing the required regeneration distance. The authors present two case reports of patients with proximal median nerve injury, who underwent radial sensory nerve transfers to the ulnar digital nerve of the thumb and the radial digital nerve of the index finger. Protective sensation returned to the index and thumb fingertips at 3 months. By 6 months, both patients attained sufficient sensation to permit active lateral key pinch. At 9 months, each patient had moving sensation; and by 14 months, each patient attained proper localization. Successful digital nerve transfers of the dorsal radial sensory nerves in patients with high proximal median nerve injuries return sensation faster than traditional median nerve repairs. Use of this technique will significantly reduce the insensate time in patients with this unfortunate injury.     

环指指动脉皮瓣与拇指桡侧逆行筋膜皮瓣瓦合修复拇指缺损

【】 目的 探讨环指指动脉顺行岛状皮瓣与拇指桡侧逆行岛状筋膜皮瓣瓦合修复拇指缺损的临床应用效果。方法 我院自2010 年4月以来对10例I类拇指缺损采用环指指动脉顺行岛状皮瓣与拇指桡侧逆行岛状筋膜皮瓣瓦合修复结合自体髂骨移植,治疗后观察皮瓣及骨愈合、皮瓣感觉功能及术后相关并发症发生情况。结果 经过12个月随访,10例拇指缺损修复良好,皮瓣及移植骨愈合良好,按中华医学会手外科学会拇、手指再造功能评定试用标准[1],优8例,良2例,无术后相关并发症发生。结论 环指指动脉顺行岛状皮瓣与拇指桡侧逆行岛状筋膜皮瓣瓦合结合自体髂骨移植修复I类拇指缺损的临床效果满意。     

Experimental sensory reinnervation of the median nerve by nerve transfer in monkeys.

Anastomosis of the superficial radial nerve, the dorsal cutaneous branch of the ulnar nerve, or both to the distal cut end of a widely resected median nerve in monkeys was followed by successful sensory reinnervation of the thumb, index finger, and long finger within thiry-five to forty weeks. Success was ascertained by the presence of an intact anastomosis as observed grossly without any evidence of spontaneous regeneration of the median nerve. Reinnervation was confirmed by histological and histochemical reactions observed in the Meissner's corpuscles in the skin innervated by the median nerve. The demonstration of nerve fiber and the presence of normal specific and non-specific cholinesterase reactions exhibited by the Meissner's corpuscles in the cholinesterase preparations were considered the histological criteria for successful reinnervation. These histological and histochemical observations may explain the reported functional sensory recovery in clinical cases when similar nerve transfers were done.     

Fourteen cases of free thenar flap: a rare indication in digital reconstruction

BACKGROUND: The thenar area was first used for a free vascularized transfer by Tsai who, in 1991, resurfaced and vascularized a traumatized index finger basing the dissection on the radial digital artery of the thumb. Later, Kamei and Omokawa described a similar flap in finger reconstruction, which was supplied either by the radial artery or its volar branch. METHODS: Between 1997 and 2005 14 free thenar flaps were performed at Chang Gung Memorial Hospital for thumb (3 cases) and digital reconstruction (11 cases). In 6 cases, the pulp was involved whereas in the remaining 8 cases, the lesion was either in the volar (6 cases) or in the dorsal surface (2 cases) of the fingers. In 7 patients, a perforating branch rising about 3 cm proximal to the wrist crease was the main vascular source of the flap. In 8 cases, the volar radial artery provided adequate blood supply to the flap. No sensory nerve was included in the flap dissection. RESULTS: Two patients underwent reexploration for arterial thrombosis and venous congestion, respectively, which resulted in complete survival in this series. Donor site morbidity was inconspicuous and, in all cases, the thenar flap provided a well-padded tissue with glabrous skin. In the 7 patients who came back for a final evaluation, 2PD showed poor recover. CONCLUSION: The free thenar flap offers a thick skin of similar glabrous texture to that of the digits. This flap is especially indicated in those cases of multiple digital injuries or wide skin defects where homodigital or heterodigital island flaps are unsuitable.     

Innervated reverse dorsal digital island flap for fingertip reconstruction

PURPOSE: Various methods of fingertip reconstruction with a sensory flap have been reported. Digital island flaps or cross-finger flaps have to be used for large defects; however, the digital artery is sacrificed when creating conventional homodigital island flaps and 2 surgeries are required for the cross-finger flap. We describe our experience with an innervated reverse dorsal digital island flap that does not require sacrifice of the digital artery. METHODS: We used innervated reverse dorsal digital flaps for fingertip reconstruction in 8 patients. The flap was supplied by the vascular network between the dorsal digital artery (the terminal branch of the dorsal metacarpal artery) and the dorsal branch of the digital artery. Venous drainage was through the cutaneous veins and the venous network associated with the dorsal arterial network. The flap was designed on either the dorsal proximal or the dorsal middle phalangeal region. The flap was harvested with the dorsal branch of the digital nerve (for the dorsal middle phalanx), the dorsal digital nerve (for the dorsal proximal phalanx), or the superficial branch of the radial nerve (for the thumb), which was anastomosed to the distal end of the digital nerve. After flap transfer the donor site was covered with a full-thickness skin graft. RESULTS: Of the 8 flaps, 6 survived completely, 1 had partial epithelial skin necrosis, and 1 showed central compression skin necrosis. Three flaps showed congestive changes from the first to the fifth day after surgery, which resolved by massage. All patients achieved satisfactory recovery of sensation; the static 2-point discrimination ranged from 3 mm to 5 mm and the Semmes-Weinstein test results ranged from 0.036 g to 0.745 g. CONCLUSIONS: The innervated reverse dorsal digital island flap provides another option for homodigital tip coverage. The advantages are that the digital artery is not sacrificed and only 1 surgery is needed. A disadvantage is the potential for venous congestion for the first 4 or 5 days after surgery.     

Reverse flow first dorsal metacarpal artery flap for covering the defect of distal thumb

Reconstruction of distal thumb injuries still remains a challenge for hand surgeons. Surgical treatment includes the use of local, regional, and free flaps. The purpose of this report is to present the results of the use of a sensitive reverse flow first dorsal metacarpal artery (FDMA) flap. The skin flap was designed on the radial side of the proximal phalanx of the index finger based on the ulnar and radial branch of the FDMA and a sensory branch of the superficial radial nerve. This neurovascular flap was used in five patients to cover distal soft‐tissue thumb defects. All flaps achieved primary healing except for one patient in whom superficial partial necrosis of the flap occurred, and the defect healed by second intention. All patients maintained the thumb original length and were able to return to their previous daily activities. The reverse flow FDMA flap is a reliable option to cover immediate and delayed defects of distal thumb, offering acceptable functional and cosmetic outcomes in respect to sensibility, durability, and skin‐match. © 2013 Wiley Periodicals, Inc. Microsurgery 34:283–286, 2014.     

Sensory reconstruction in sensate radial forearm flap transfer

The authors treated 14 patients (13 men and one woman), using a sensate radial forearm flap. Their ages at operation ranged from 27 to 67 years (mean: 52 years). Preoperative conditions were amputations in 10 cases, degloving injury in three, and crush injury in one. Reconstructive sites involved the thumb in nine cases, the mitten-like hand in two, the index finger in one, the ring and small finger in one, and the palm in one. In all cases, the radial forearm flap, including the lateral antebrachial cutaneous nerve, was harvested. Sensory evaluation was performed using the moving two-point discrimination test (m-2PD). Sensation in the mid-palmar area of 50 forearms was examined in 25 healthy adult volunteers as a control group. Follow-up periods ranged from 12 to 87 months (mean: 39.6 months). The mean m-2PD of the 14 sensory flaps was 13.2 mm, and the mean of 50 forearms in the control group was 18.08 mm. A statistically significant difference was demonstrated between the sensory flaps and the 50 forearms of the control group. The mean m-2PD was much more sensitive in the innervated radial forearm flaps than in the donor forearm. The results suggested that sensory return in the innervated flaps is influenced not by the donor nerve in the flaps, but by the recipient digital nerve.     

拇指撕脱离断伤再植术中两侧指固有神经的修复

目的介绍拇指撕脱离断伤再植术中修复拇指两侧指固有神经的方法。方法1999年8月-2009年4月,在12例拇指撕脱离断伤再植术中,采用食指桡侧指固有神经背侧支和桡神经浅支第2指蹼支移位的方法,修复拇指两侧指固有神经。结果12例拇指撕脱离断伤均再植成功,均获随访1～2年,平均16月。拇指两侧感觉均恢复良好,两点分辨觉小于10mm,平均约7mm,按照感觉功能评定标准为S4。结论拇指撕脱离断伤再植术中,应用食指桡侧指固有神经背侧支与桡神经浅支第2指蹼支移位,能恢复拇指指腹两侧良好感觉。     

第一掌骨背逆行筋膜皮瓣修复拇指皮肤缺损

目的介绍一种修复拇指皮肤缺损的新型逆行筋膜皮瓣。方法取１０只新鲜尸体手，从桡动脉灌注红色乳胶，对第一掌骨背及拇指指背软组织的血管进行显微解剖，根据其血管分布设计成第一掌骨背逆行筋膜皮瓣。自甲根部桡侧缘至第一掌骨同侧背侧缘的连线为轴心线，其蒂部宜设在拇指指间关节近侧１ｃｍ以近的轴心线上。结果第一掌骨背及拇指指背软组织的血供主要由拇指两条指掌侧固有动脉向指背侧发出的分支，在指背筋膜内与两侧指背动脉及桡神经浅支伴行血管（桡、尺侧各２条）形成的血管网提供。１９９６年２月～１９９７年９月，临床应用该皮瓣修复拇指皮肤缺损６例，皮瓣全部成活。结论第一掌骨背及拇指指背软组织血供丰富，可形成第一掌骨背逆行筋膜皮瓣。该皮瓣设计合理、血供可靠、操作简便，适用于修复拇指，尤其是拇指桡侧皮肤的缺损     

Innervated boomerang flap for finger pulp reconstruction

The boomerang flap originates from the dorsolateral aspect of the proximal phalanx of an adjacent digit and is supplied by the retrograde blood flow through the vascular arcades between the dorsal and palmar digital arteries. To provide sensation of the boomerang flap for finger pulp reconstruction, the dorsal sensory branch of the proper digital nerve and the superficial sensory branch of the corresponding radial or ulnar nerve are included within the skin flap. After transfer of the flap to the injured site, epineural neurorrhaphies are done between the digital nerves of the pulp and the sensory branches of the flap. We used this sensory flap in five patients, with more than 1 year follow-up, and all patients achieved measurable two-points discrimination. The boomerang flap not only preserves the proper palmar digital artery but also provides an extended and innervated skin paddle. It seems to be an alternative choice for one-stage reconstruction of major pulp defect.     

Compression neuropathy of the radial palmar thumb nerve

Compression neuropathy of a single digital nerve is a rare entity. We report the case of a patient with numbness in the distribution of the radial digital nerve of the thumb caused by the use of a walking stick. The nerve was compressed between the handle of the stick, the loop and the radial sesamoid bone of the first metacarpophalangeal joint. The site of the lesion was confirmed by electrophysiologic examination. Orthodromic recording of the sensory response from the radial palmar digital nerve of the thumb documented a complete absence of nerve action potential whereas the ulnar digital thumb nerve showed a normal response. Sensory function was restored when a padded ski glove was used to protect the area of the metacarpophalangeal joint whilst using the stick.     

指背血管蒂岛状皮瓣修复拇指组织缺损

目的 探讨拇指组织缺损的修复方法。方法 利用8具尸体16只手进行解剖学研究，观察了拇指背动脉、第1掌背动脉及食指桡侧指背动脉。临床上分别以拇指背动脉、示指桡侧指背动脉为蒂于手背侧设计岛状皮瓣进行应用。结果 拇指背动脉外径0．24～0．46mm，平均0．37mm，示指桡侧指背动脉0．26～0．56mm，平均0．44mm，血管恒定。临床应用拇指背血管蒂逆行皮瓣、示指桡侧指背血管蒂皮瓣修复拇指组织缺损12例；皮瓣带人桡神经指背支形成有感觉皮瓣，效果更满意。结论 以指背血管为蒂的手背侧皮瓣是修复拇指组织缺损的较为理想方法。     

食指桡侧指固有动脉转位套入法治疗拇指断指

目的：探讨食指桡侧指固有动脉转位套入法治疗拇指断指的疗效。方法对10例指动脉缺损而无肌腱神经缺损的拇指完全或不完全离断病例,采用食指桡侧指固有动脉转位与拇指尺侧指固有动脉行套入吻合法修复动脉,再植拇指。结果本组10例再植拇指均成活,指腹饱满,色泽红润,经6~24个月随访,患者手部功能恢复满意,外观自然,2例出现虎口狭窄,经手术改善。结论食指桡侧指固有动脉转位套入法适用于单纯拇指指动脉缺损的再植治疗。     

带神经的邻指皮瓣修复示中环指指腹缺损

目的 介绍一种修复示、中、环指指腹缺损的方法。方法 运用带有尺侧指固有神经背侧支的邻指皮瓣,修复示、中、环指指腹缺损,并将所带神经吻合于桡侧指固有神经残端。术后待皮瓣断蒂后测量并随访其疗效。结果 皮瓣全部成活,外观良好,患者自觉满意。随访并测量两点辨别觉桡侧达5～7mm,尺侧达8～10mm。结论 对于示、中、环指指腹缺损,修复其创面,恢复其感觉功能,尤其是桡侧的皮肤感觉功能比较重要。此方法操作简单、成活率高,值得推广。     

Neural anatomy of the radial forearm flap

Typically the lateral antebrachial cutaneous nerve alone is used to innervate the radial forearm free flap when a sensate flap is required. The authors desired, by means of fresh cadaveric microdissections and by means of local anesthetic injections in living subjects, to map the sensory nerve territories of this flap. Eight radial forearm flaps were elevated and the medial antebrachial cutaneous nerve (MABC), lateral antebrachial cutaneous nerve (LABC), and superficial radial sensory nerve (SRSN) were dissected with the aid of an operating microscope (2.5-10x) and traced to their dermal insertions. In the injection study, the MABC, LABC, and SRSN in eight forearms of 4 subjects were blocked sequentially with 2% lidocaine injections. The resulting sensory deficit from each injection was mapped on the skin and superimposed on the marked radial forearm flap territory. Distribution of the three dissected nerve regions and the sensory deficit after injection were determined by digital images and computer analysis. During flap dissections, mean nerve distributions of total flap area were as follows: LABC, 61.8% (range, 48.3-71.6%); MABC, 33.8% (range, 30.5-38.9%); and SRSN, 34.6% (range, 26.8-44.1%). After nerve block the mapped sensory areas were as follows: LABC, 62.3% (range, 44.5-88.5%); MABC, 19.6% (range, 8.0-35.8%); and SRSN, 19.5% (range, 9.9-26.3%). At least 40% of the total flap area was not innervated by the LABC as identified both by nerve dissection and sensory local anesthetic blockade. By including the LABC, MABC, and SRSN in the radial forearm flap, both the theoretical and the clinically determined useful sensory innervation of the radial forearm flap potentially would be increased.     

Further experience with the bipedicled neurovascular island flap in thumb reconstruction

A procedure is described for the transfer of sensibility to the thumb by means of an island flap. The donor site is the dorsoradial surface of the index finger. The flap is supplied by two neurovascular pedicles. The palmar one includes the digital artery of the index and the dorsal branch of the palmar digital nerve. The dorsal pedicle includes the dorsoradial artery and nerve of the index and one or two superficial veins. This procedure was used in 29 patients without early postoperative complications. The advantages of the method are the resurfacing of the prehensile surface of the thumb by a flap with good arterial and venous supply while preserving the innervation and the palmar skin of the donor finger.