Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

Primary soft-tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 x 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches from the palmar digital nerve supplying the midpalmar area. From this study, two different reverse flaps were proposed. First, a 5 x 2 cm flap from the distal midpalmar region was elevated on the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal joint level and could cover the finger pulp of the digits. The second flap candidate was that from the radial aspect of the midpalm, which was supplied by the terminal branch of the superficial palmar arch. In studies with cadaver hands, connection of this artery with the deep arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft-tissue loss of the fingers.     

A reverse ulnar hypothenar flap for finger reconstruction

A reverse-flow island flap from the hypothenar eminence of the hand was applied in 11 patients to treat palmar skin defects, amputation injuries, or flexion contractures of the little finger. There were three female and eight male patients, and their ages at the time of surgery averaged 46 years. A 3 x 1.5 to 5 X 2 cm fasciocutaneous flap from the ulnar aspect of the hypothenar eminence, which was located over the abductor digiti minimi muscle, was designed and transferred in a retrograde fashion to cover the skin and soft-tissue defects of the little finger. The flap was based on the ulnar palmar digital artery of the little finger and in three patients was sensated by the dorsal branch of the ulnar nerve or by branches of the ulnar palmar digital nerve of the little finger. Follow-up periods averaged 42 months. The postoperative course was uneventful for all patients, and all of the flaps survived without complications. The donor site was closed primarily in all cases, and no patient complained of significant donor-site problems. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer, as indicated by 5 mm of moving two-point discrimination. A reverse island flap from the hypothenar eminence is easily elevated, contains durable fasciocutaneous structures, and has a good color and texture match to the finger pulp. This flap is a good alternative for reconstruction of palmar skin and soft-tissue defects of the little finger.     

Ramification pattern of intermetacarpal branches of the deep branch (ramus profundus) of the ulnar nerve in the human hand.

The branching pattern of the deep branch (ramus profundus) of the ulnar nerve and its relation with the target were analyzed in the human hand by an improved dissection method. After sending off branches to the hypothenar muscles, the r. profundus branched off an ulnar stem and a radial stem to the fourth, to the third and to the second intermetacarpal spaces, respectively, in this order, and an ulnar stem to the first to become terminal branches. The ulnar stems included an ulnar interosseous branch and a superficial articular branch in addition to a lumbrical branch in the third and fourth intermetacarpal spaces. The radial stems included only a radial interosseous branch. The branching pattern of the ulnar stems as well as its topographical relationship with the radial stems indicated a fundamental spatial arrangement of the branches in the intermetacarpal spaces: the lumbrical, superficial articular, ulnar interosseous and radial interosseous branches were arranged fundamentally in this order from ulnar to radial in each space; the first three branches may form a common trunk. The present observations demonstrate that individual nerves in the extremities may have a regular branching pattern, contrary to most of the previous observations.     

A surgical approach to the motor branch of the ulnar nerve

Isolated injury to the motor branch of the ulnar nerve is a relatively rare injury, often initially misdiagnosed. If repair is attempted through the original laceration without complete motor branch exposure, results can be less than satisfactory. A recent case illustrates this injury and provides us with an opportunity to review the surgical anatomy of the motor branch of the ulnar nerve. The surgical approach to the motor branch has been detailed and specifically emphasizes complete motor branch exposure from the main ulnar nerve trunk to the most distal motor branch entry into the adductor pollicis muscle. This approach permits definition of the exact level of the nerve injury, preservation of any intact proximal fine motor branches, and facilitates the mechanics of nerve repair.     

The dorsal arterial network of the wrist with reference to the blood supply of the carpal bones.

The gross examination of 50 minium injected specimens showed us the various patterns of the posterior arterial network of the wrist. This is chiefly provided by the radial artery which gives off a constant dorsal carpal branch over the posterior aspect of the trapezium. This vessel crosses the carpus transversely to the inner border of the hand and is joined in half of the cases by the interosseous artery; contribution of the posterior carpal branch of the ulnar artery was more rarely found than usually described (25%). From the arch thus formed are given off short branches which run upwards along the intercarpal joints and enter the posterior aspects of the proximal carpal bones whose lower halves seem to be the most favorably supplied. On the contrary, the distal carpal bones receive several short twigs which penetrate their posterior surfaces. Although the arrangement of the pedicles may undergo many a variation, attention must be drawn to the fact that the dorsal arteries are smaller but denser than the volar, except for the hamate. Therefore 2 different patterns of arterial supply can be described at the carpus: the blood supply of the outer and axial bones--scaphoid, trapezium, lunate, capitate--derives from the radial and the interosseous arteries and is probably shared equally by volar and dorsal branches; the inner bones--triquetrum, hamate--are primarily supplied by volar or medial branches coming almost exclusively from the ulnar artery.     

Pattern formation of the sensible nerves in the hand of mouse embryos with special reference to the posterior-anterior developmental gradient

The development of the sensible innervation of the hand was investigated. For this reason normal forelimbs and limb bud cultures from 12- to 14-day-old mouse embryos were stained in toto using the cholinesterase technique. The dorsal side of the hand is mainly innervated by sensible branches of the radial and the musculocutaneous nerve, which penetrate the fascia in the region of the elbow. From here they grow in a distal direction forming the dorsal digital nerves. On the ventral side the median nerve grows in a subfascial compartment towards the palmar side of the hand. While passing the wrist the median nerve exhibits a frayed appearance. A net of branching and anastomosing small nerve fibre bundles is visible. This implies that on the palmar side of the metacarpal region of the hand-plate no specific highways for the growing nerve fibres exist. From late day 12 to early day 14 of embryonic development this diffuse nerve net is organized. In a posterior-anterior (ulnoradial) developmental gradient the common palmar digital nerves were formed, and these nerves divide at their tip into the proper digital nerves. However, the proper digital nerves again follow special pathways during their outgrowth.     

Anomalous pattern of median artery in the forearm of Indians

Various anomalous relations between the brachial plexus or its branches and arteries are reported. The present study was conducted on 134 limbs to note the origin and course of the median artery and its relation to the median nerve. In 2 limbs (1.5%), the median artery split the median nerve into two roots in the forearm and the artery passed through the nerve. In both of these limbs (1.5%), the median artery arose from the ulnar artery. The median artery in these 2 limbs (1.5%) was considerably large and supplied the hand. Both the origin of the median artery from the ulnar artery and the splitting of the median nerve by the median artery are rare anomalies which have not been reported in the available literature.     

Thenar and hypothenar muscles and their innervation by the ulnar and median nerves in the human hand.

The thenar and hypothenar muscles as well as their supplying nerves were analyzed with an improved dissecting method. Among the four thenar muscles, the m. abductor pollicis brevis (AbPB) has a separate muscle belly, whereas the m. opponens pollicis (OP), the superficial and deep heads of the flexor pollicis brevis (sFPB and dFPB), and the adductor pollicis (AdP) are fused with each other to make a single mass (deep thenar muscle group). These muscles are innervated by branches of the recurrent nerve and the accessory recurrent nerve from the median nerve as well as by terminal branches of the deep branch (ramus profundus) of the ulnar nerve. These three nerves frequently form a loop within the deep thenar muscle group (thenar loop), and a branch to the OP and one to deep parts of the sFPB often make a smaller loop (intrathenar loop), whereas the AbPB receives a separate nerve branch. Among the hypothenar muscle, the m. abductor digiti minimi and the m. flexor digiti minimi brevis are fused with each other, and their supplying nerves frequently form a loop in these muscles (intrahypothenar loop), whereas the m. opponens digiti minimi is separated from the others and receives a separate nerve branch. In the distribution pattern of supplying nerves to the thenar and hypothenar muscles, we find regularities in that they branch off in a regular manner from the ulnar and the median nerve, and that nerve branches to those muscles with fused bellies frequently communicate with each other to make loops.     

The arteria radialis superficialis. An unusual variation of the arteria radialis of man and its phylogenetic significance

During the clinical investigation of 570 soldiers of the German army, we were not able to feel the pulse in 5 cases at the typical place of the radial pulse in the distal part of the forearm. In these 5 cases we were able to find a subcutaneous artery which coursed superficial to the anatomical snuffbox and crossed superficial to the tendon of the extensor pollicis longus muscle. This superficial radial artery enters the deep aspect of the palm between the first and the second metacarpale bones. In three cases we found a bilateral occurrence of this artery, the other variations were observed unilaterally, two on the right side and one on the left side of the forearm. In the family of two patients other members were found who had the same variation of the radial artery. In one of the cases an arteriography of the vessels was made to find the exact anatomical course of the observed variation. We compared our results with the literature on this variation of the radial artery and found agreement on the following course for this vessel. The radial artery divides in the distal fourth of the forearm (5-7 cm proximal to the wrist joint) into two branches. The dorsal branch courses subcutaneously over the tendon of the brachioradialis muscle and runs over the tendon of the extensor pollicis longus muscle to enter the deep aspect of the palm in the first metacarpal space. This dorsal branch courses parallel to the superficial branch of the radial nerve. The palmar branch can be regarded as the 'normal' radial artery, which continues along the medial border of the brachioradialis muscle and courses deep under the tendons of the dorsal muscles of the thumb. The rare appearance (frequency approximately 1%) of a superficial radial artery in man has probably some phylogenetic importance. This is proven by studies on the comparative anatomy of mammals. This variation of the radial artery seems to be homologous to the superficial radial artery which is described in many lower mammals. In human embryos a superficial radial artery is found as well which courses parallel to the superficial branch of the radial nerve and ends on the dorsal side of the hand. Taking all the anatomical and embryological facts into consideration we propose to name this variation of the radial artery the 'arteria radialis superficialis'.     

Free flap from the flexor aspect of the wrist for resurfacing defects of the hand and fingers

The distal portion of the flexor aspect of the forearm has been used as the donor site of full-thickness skin grafts, venous skin grafts, and Chinese forearm flaps. This article describes the use of a free flap harvested from the flexor aspect of the wrist and based on the superficial palmar branch of the radial artery to repair skin defects of the hand and fingers. The advantages of this flap are as follows: (1) the operative field is the same; (2) the radial artery is preserved; (3) it is thin, pliable, and hairless and thus can supply a gliding surface for tendons beneath it; (4) when it involves a palmaris longus tendon and/or the palmar cutaneous branch of the median nerve, it can be used as a vascularized tendon or nerve graft; and (5) in view of the flow-through type of the pedicle of the flap, the digital artery can be reconstructed simultaneously. However, it should be noted that a hypesthesia in the proximal central carpal area remains when the palmar cutaneous branch of the median nerve is harvested as a vascularized nerve graft. The scar of the donor site should be left in the distal wrist crease. If it is not lying in the distal wrist crease, it may suggest that the patient has tried to commit suicide.     

The position of crossing branches of the medial antebrachial cutaneous nerve during cubital tunnel surgery in humans

The posterior branch of the medial antebrachial cutaneous nerve courses in proximity to the cubital tunnel and is particularly prone to injury during ulnar nerve release at the elbow. Inadvertent injury to medial antebrachial cutaneous nerve branches during surgery can result in the formation of painful neuromas that can be misdiagnosed as recurrent disease. It is important to understand the relevant anatomy of the medial antebrachial cutaneous nerve branches during cubital tunnel surgery to avoid significant postoperative morbidity. This prospective observational anatomic study examined the position of the posterior branch of the medial antebrachial cutaneous nerve in relationship to a standard approach to the cubital tunnel in a randomly selected group of 97 patients undergoing primary surgery over a 3-year period. Medial antebrachial cutaneous nerve branches were noted to cross at or proximal to the medial humeral epicondyle 61 percent of the time at an average proximal distance of 1.8 cm. Medial antebrachial cutaneous nerve branches were noted to cross distal to the medial humeral epicondyle 100 percent of the time at an average distal distance of 3.1 cm. Understanding the general position of crossing medial antebrachial cutaneous nerve branches during ulnar nerve release at the elbow may help to prevent iatrogenic injury to this cutaneous nerve.     

Quantitative freeze-fracture analysis of the frog neuromuscular junction synapse – II. Proximal–distal measurements

Neurotransmitter release from different parts of frog motor nerve terminals is often non-uniform. There is a decrease in release efficacy from the distal regions of frog motor nerve terminal branches. Since release is thought to occur near the double arrays of large intramembranous particles that constitute the pre-synaptic active zones (AZs), we have examined quantitatively the proximal–distal distribution of AZ structure, using a novel freeze-fracture technique that produces replicas of large fractions of terminals, including the region of nerve entry. This enables us to know the proximal–distal orientation of each branch. From 23 end-plates we have obtained fractures of 72 branches. For 27 of these branches we have obtained continuous fractures both greater than 25 μm in length and with sufficient information to determine their proximal–distal polarity. Only a few of these branches showed a marked distal decrease in AZ length/unit length of terminal, while several junctions had short regions (5–10 μm), either proximally or distally, that exhibited amounts of AZ that were substantially greater or smaller than the mean value for that terminal branch. The terminal area, post-synaptic gutter width and nerve terminal width all exhibit some distal decline concomitant with the distal tapering of nerve terminal branches. AZ length tends to have the least decline compared to the other parameters. Thus, the vast majority of frog motor nerve terminal branches do not display a significant proximal-distal gradient in the amount of AZ structure/μm terminal length. The present data do not provide an obvious ultrastructural correlate for the distal decline in transmitter release that some authors have observed.     

Innervated radial thenar flap combined with radial forearm flap transfer for thumb reconstruction

A radial thenar flap combined with radial forearm flap was used for the reconstruction of the ipsilateral thumb in four patients. Vascular supply of the combined flap was based on the radial artery and extending the vascular pedicle to the superficial palmar branch of the radial artery. The flap was sensated by the palmar branch of the superficial radial nerve. The size of the flap averaged 15 x 5 cm and the innervated region of the thenar eminence was an area approximately 5 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. The flap was transferred as a free flap in three patients and as an advancement flap in one patient. The flaps survived completely without complications. Satisfactory restoration of sensation was achieved in the flap area, as shown by 6 mm of average moving two-point discrimination. This combined flap may be a feasible reconstructive option for large palmar defects of the fingers such as degloving injuries.     

The vascularization of the neural stalk and the pars nervosa of the hypophysis in the toad,Bufo bufo (L.) (amphibia,anura)

The angioarchitecture of the neural stalk and the encephaloposthypophysial portal system of the hypophysis of the toad, Bufo bufo (L.), was studied using three different methods. The neural stalk is mainly supplied by branches of the arteria infundibularis superficialis which form a widemeshed vascular network. Dorsally this network continues into the plexus of the pars nervosa. The vascularization of the pars nervosa is made up of the encephalo-posthypophysial portal system. This portal system consists of a hypothalamic branch (=portion), a mesencephalic and a mesencephalicbulbar branch (=portion). The hypothalamic branch was found to drain the pars ventralis of the tuber cinereum as well as more dorsal regions of the diencephalon. The mesencephalic-bulbar trunk enters the hypothalamic branch. The resulting common stem of the encephalo-posthypophysial portal vein the curves around the retroinfundibular communicating artery, crosses its ventral side and runs caudally. The secondary capillary plexus of the pars nervosa is characterized by well defined capillary plexus of the pars nervosa is characterized by well defined capillary networks which are located at the periphery of the parenchyma of the pars nervosa, thus forming a rostral, dorsal and ventro-caudal net. The central region of the parenchyma of the pars nervosa is supplied only by main branches of the encephalo-postpophysial portal vein. The venous drainage of the pars nervosa is via the vena hypophysea transversa.     

Innervation pattern of the gill arches and gills of the carp (Cyprinus carpio)

The innervation pattern of the respiratory gill arches of the carp (Cyprinus carpio) is described. The gill region is innervated by the branchial branches of the glossopharyngeal and vagal nerves. Each branchial nerve divides at the level of or just distal to the epibranchial ganglion into: 1) a pretrematic branch, 2) a dorsal pharyngeal branch, and 3) a posttrematic branch. The dorsal pharyngeal branch innervates the palatal organ in the roof of the buccal cavity. The pretrematic and posttrematic branches innervate the posterior and anterior halves, respectively, of the gill arches bordering a gill slit. Each branch splits into an internal and an external part. The internal bundle innervates the buccal side of the gill arch, including the gill rakers. The external bundle terminates in the gill filaments. The epibranchial motor branch, a small nerve bundle containing only motor fibers, circumvents the ganglion and anastomoses distally with the posttrematic branch. The detailed course and branching patterns of these branches are described.     

Aneurysm of the median artery causing recurrent carpal tunnel syndrome and anatomic review

A patient is presented who had recurrent carpal tunnel syndrome symptoms in his left hand 1 year after having undergone release of the transverse carpal ligament. On exploration, this was found to be due to an aneurysm of a median artery and possibly scarring due to this compression around the branches of the bifurcated median nerve. This represents the first case in the literature to comment on (1) the absence of bilaterality of the anatomic finding and (2) carpal tunnel syndrome relative to median artery aneurysm. With this in mind, a plea is made for careful exploration of the carpal tunnel, maintaining an incision as far to the ulnar side of the median nerve as technically possible with thorough visualization of the contents of the tunnel and any anatomic variance involved. The incidence of the combination of aberrant median artery with high bifurcation of the median nerve is unknown, as is the incidence of aneurysm of the median artery.     

Vascular anatomy of the forearm muscles: a study of 50 dissections

This anatomic study is based on 50 adult cadaver upper extremities. The general disposition of the forearm arteries and muscles and the main anatomic variations encountered are specified. Constant existence of an "anterior oblique artery" satellite of the pronator teres was established. The median nerve artery was principally dedicated to the flexor digitorum superficialis and participated appreciably in the constitution of palmar arches in only one case. A supernumerary intermedial radial muscle was found only in two cases. The abductor pollicis longus and extensor pollicis brevis appeared as a single muscular and vascular unit in 84 percent of cases. All the arteries destined for muscles were reckoned whatever their caliber might be. Despite its limitations, this study confirms the very great number of the forearm muscular pedicles. Each forearm contained an average of 264 muscular vascular pedicles. The systematization of the origins and destinations of the 13,158 muscular pedicles is described in a numbered manner for each of the 20 normal forearm muscles and for each of the 12 studied arterial segments. The pronator teres was likely to be supplied by all the anterior arteries of the upper limb. The flexor carpi radialis had one or two dominant pedicles originated from the recurrens ulnaris anterior, recurrens ulnaris, or ulnaris-interossea communis arteries, and many transversal branches originated from the radial artery. The flexor carpi ulnaris was supplied in its proximal third by the recurrens ulnaris posterior artery and in its distal two-thirds by many branches of ulnar artery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Periosteal and endosteal blood supply of the human fibula and its clinical importance]

The angioarchitecture of the human fibula was investigated by anatomical dissection. The main artery of the periosteal and endosteal blood supply is the arteria fibularis. The proximal part of the facies lateralis is additionally nourished by a well-built branch of the arteria tibialis anterior. The periosteal branches of the arteria fibularis are most voluminous on the dorsal side in the middle of the fibula. Small plates take care of these branches. For an additional revascularization the well-built branch of the arteria tibialis anterior is proposed. The best anatomical region for a vascularized fibular transfer is at an average of 20% up to 75% of the fibular length.     

The superior laryngeal nerve and the superior laryngeal artery

Length, diameter and anastomoses of the nervus vagus and its ganglion inferius were measured 44 halved heads. On the average, 8.65 fiber bundles of the vagus nerve leave the retro-olivary area. In the area of the jugular foramen is the near superior ganglion of the 10th cranial nerve. In this area were found 1.48 (mean value) anastomoses with the 9th cranial nerve. 11.34 mm below the margo terminalis sigmoidea branches off the ramus internus of the accessory nerve which has a length of 9.75 mm. Further anastomoses with the 10th cranial nerve were found. The inferior ganglion of the 10th nerve had a length of 25.47 mm and a diameter of 3.46 mm. Five mm below the ganglion the 10th nerve had a width of 2.9 and a thickness of 1.5 mm. The mean length of the superior sympathetic ganglion was 26.6 mm, its width 7.2 and its thickness 3.4 mm. In nearly all specimens anastomoses of the superior sympathetic ganglion with the ansa cervicalis profunda and the inferior ganglion of the 10th cranial nerve were found. The superior laryngeal nerve branches off about 36 mm below the margo terminalis sigmoidea. The width of this nerve was 1.9 mm, its thickness 0.8 mm on the right and 1.0 mm on the left side. The division in the internal and external rami was found about 21 mm below its origin. Between the n. vagus and thyreohyoid membrane the ramus internus had a length of 64 mm, the length of external ramus between the vagal nerve and the inferior pharyngeal constrictor muscle was 89 mm. Its mean length below the thyreopharyngeal part was 10.7 mm, 8.6 branchlets to the cricothyroid muscle were counted. The superior laryngeal artery had its origin in 80% of cases in the superior thyroideal artery, in 6.8% this vessel was a branch of the external carotid artery. Its average outer diameter was 1.23 mm on the right side and 1.39 mm on the left. The length of this vessel between its origin and the thyreohyoid membrane was 34 mm. In 7% on the right side and in 13% on the left, the superior laryngeal artery reached the larynx through a foramen thyreoideum. Ranges of diameters and lengths of vessels and nerves in the larynx are given.     

Clinical anatomy of the m. flexor carpi radialis tendon sheath

At the transitional zone from the forearm to the hand the insertion tendon of the m.flexor carpi radialis (FCR) glides on a fibrous and fatty cushion, which is connected dorsally with the joint capsule of the radiocarpal articulation. The tendon distally crosses the palmar side of the scaphoid tubercle and enters the dorsally curved rim of the trapezoid tubercle. At the level of the wrist joint the narrow tendon sheath begins, which extends to the insertion at the metacarpus. Immediately after entering the gliding tunnel the tendon branches off radially as a rule with an accessory fibre strand 8 mm in width to the scaphoid, trapezium and the joint capsule between these two bones. The insertion tendon regularly is attached to the palmar and radial surfaces of the second and third metacarpal bones. The wall of the osteofibrous gliding tunnel can be prominent following trauma, inflammation or arthrosis deformans in the trapezio-scaphoideal joint and may irritate the tendon (tendovaginosis stenosans). Against resistance forces pain will occur in the wrist joint during palmar flexion. The typical point of tenderness is situated at the entering of the tendon in the thenar region. Operative decompression will be effective by opening the radial wall of the tendon sheath from the carpal tunnel.