Anatomic observation of the dorsal metacarpal arteries

Anastomosis between the first to the fourth dorsal metacarpal arteries was observed in 43 hands of adult corpses. It was found that 86% of the first dorsal metacarpal artery arises from the radial artery, 14% is replaced by the main artery of thumb or superficial branches of the radial arteries; eighty-six percent of the second dorsal metacarpal artery originates from the dorsal carpal artery. Sixty-seven percent of the third and the fourth dorsal metacarpal arteries is formed by anastomosis of the dorsal carpal artery and its deep palmar arch. The first to the fourth dorsal metacarpal arteries have 4 to 8 cutaneous branches and proximal and distal anastomoses. It is concluded that the dorsal metacarpal arteries are characterized with multiple sources and abundant anastomoses around the metacarpophalangeal joints, which can be used with advantage in the repair of soft tissue defects of the area.     

The compartments of the hand: an anatomic study

To determine the nature and number of enclosed myofascial spaces in the hand, an anatomic study that included 21 cadaver hands was conducted using a gelatin injection method. Data were collected from the prepared cross-sections of each specimen. The results showed the thenar space to comprise 2 or more discrete compartments in 52% of the hands. In 76% of the specimens, the hypothenar space demonstrated at least 2 compartments. The adductor pollicis and first dorsal interosseous muscles were discrete compartments in 71% of the hands. The interosseous compartments demonstrated significant variability. The dorsal and palmar interosseous muscles were discrete compartments within the second interosseous compartment in 48% of the hands, within the third interosseous compartment in 67%, and within the fourth interosseous compartment in 33%. Subcompartmentalization of the enclosed myofascial spaces of the hand should be anticipated in cases requiring fasciotomy. Thorough inspection within anatomic areas or generous release of the muscular origin along the metacarpal at the time of fasciotomy is suggested to ensure complete inspection.     

Clinical anatomy of the interosseous arteries of the forearm

In recent years, several local flaps have been developed, based on the anterior and posterior interosseous arteries and their anastomoses at the wrist (e.g. posterior interosseous flap, pronator quadratus flap etc.). The anatomy of the arterial network supplying the flap is well established in both clinical and anatomical literature. Most authors agree in the constancy of the anastomoses between the interosseous arteries at the wrist and the absence of major anatomical variations excluding the use of the flap. In the present study, which is based on cadaver dissections of 60 preserved specimens, several gross vascular variations of the interosseous arteries have been found. The most frequent types were an additional anastomosis between the posterior interosseous artery and a perforating branch of the anterior interosseous artery in the middle third of the forearm, which was found in 20%. Ring-formations of the palmar and the dorsal branch of the anterior interosseous artery occurred in 5%. The point of perforation of the interosseous membrane by the dorsal branch of the anterior interosseous artery was found to vary in a larger extent, as described previously.     

Histology and ultrastructure of arteries, veins, and peripheral nerves during limb lengthening

The effects of lengthening of the metacarpal bone on peripheral nerves and blood vessels were studied in 8 calves. Specimens for light and electron microscopy were obtained from the palmar neurovascular bundle at 1 cm (8% of the initial length), 2.5 cm (20% of the initial length), and 4 cm (33% of the initial length) of metacarpal lengthening. In 2 calves, specimens were studied 2 months after the end of the lengthening procedure. At 8% of lengthening, myelinated fibers of the palmar nerve showed moderate degenerative changes in the myelin sheath. This became severe at 20% and 33% of lengthening, and affected the axoplasm as well. At 20% of lengthening, the palmar vein started to show fibrous metaplasia of the smooth muscle tissue of the tunica media. This became much thinner than normal. The palmar artery showed moderate alterations of the inner part of the tunica media and the intima. The palmar nerve and blood vessels recovered their normal structure almost completely 2 months after the end of the lengthening procedure. The morphologic alterations of peripheral nerves and vessels may constitute the pathophysiologic basis of the nervous and circulatory disturbance observed in clinical practice.     

The second dorsal metacarpal flap with vascular pedicle composed of the second dorsal metacarpal artery and the dorsal carpal branch of radial artery

A pedicle second dorsal metacarpal flap, comprising the second dorsal metacarpal artery, the partial carpal arterial arch of the dorsal hand, and the dorsal carpal branch of radial artery, was designed. The flap may be rotated through two axes of rotation, one at the entry of carpal branch of radial artery into the first dorsal interosseous muscle and one at the entry of the recurrent cutaneous branch arising from the second dorsal metacarpal artery into the skin. The method introduced can increase as much as possible the length of the vascular pedicle of the second dorsal metacarpal flap. Thus, it can cover a small defect at a more distant area. If the width of this flap is not more than 3 cm, the donor site can be closed directly. The flap had been used in five cases with no necrosis of the flap or complication of the donor site. In further investigation of the postoperative patients, no stiffness and tightness have been observed through a short period of rehabilitation of the hand. The results are satisfactory. The anatomy, the operative technique, and three selective cases are described here.     

Hand injuries due to fireworks explosion

Two different series of patients with burst injuries of the hand were retrospectively reviewed: one series included 23 men, 15-55 years old, referred to the emergency department for the first-instance assessment of injuries of the right hand (13 patients) and left hand (10 patients). The other series included 44 patients (42 men and 2 women, aged 7-61 years) referred to our department for second-instance examinations: the latter patients had burst injuries involving only the hands in 43 cases and both the hand and the foot in one case. We report the radiologic patterns of traumatic bone injuries (fractures and amputations) and of musculotendinous and cutaneous injuries and discuss their mechanisms and pathogenesis. The two series were compared and the results follow: in both series the right hand was more frequently involved, metacarpal bones were most often fractured and phalanges most often amputated. In the first series, in the right hand the carpal bones were involved in one patient only, the 2nd and 3rd metacarpal bones were most frequently fractured and the 2nd finger was most frequently involved. In the left hand, the carpal bones were never affected, the 1st metacarpal bone was most often amputated and the 5th metacarpal bone most often fractured; the 2nd finger was most frequently involved. In the second series, in the right hand, the 1st metacarpal bone was most frequently fractured and the 2nd metacarpal bone most often amputated; the 2nd finger was most frequently involved. In the left hand, the 4th metacarpal bone was most frequently fractured and the 5th metacarpal bone most often amputated. The severity of the above injuries and the extent of tissue damage depend on several factors, including firecracker speed, shape, size, weight and characteristics. Radiologic exams are very useful for the accurate study of these traumatic injuries, providing indirect information about musculotendinous and cutaneous involvement. Prompted by the relative lack of information on the management of these injuries, we suggest that radiologic exams be quickly performed to help choose the most appropriate surgical approach for best cosmetic and functional results.     

Posterior interosseous reverse forearm flap: experience with 80 consecutive cases

The results of an anatomic investigation performed in 40 fresh cadaver specimens and 80 consecutive clinical cases of the posterior interosseous reverse forearm flap are reported. It was observed that there is a choke anastomosis between the recurrent dorsal branch of the anterior interosseous artery and the posterior interosseous artery at the level of the middle third of the posterior forearm. Ink injections through a catheter placed in the distal part of the anterior interosseous artery stained the distal and middle thirds of the posterior forearm, but the proximal third remained unstained; this secondary territory cannot be captured through the choke anastomosis between the anterior interosseous artery and the posterior interosseous artery. Intravital fluorescein injection into the distal arterior interosseous artery revealed (under ultraviolet light) that the distal third of the posterior forearm is irrigated by direct flow through the recurrent branch of the arterior interosseous artery (the traditionally called distal anastomosis of the interosseous arteries). Therefore, we can assume that the blood flow is not reversed when the so-called posterior interosseous reverse forearm flap is raised. From this point of view, this flap could be renamed as the recurrent dorsal anterior interosseous direct flap; however, the classical name is maintained for practical purposes. From the venous standpoint, the cutaneous area included in this flap belongs to an oscillating type of venous territory and is connected to the deep system through an interconnecting venous perforator that accompanies a medial cutaneous arterial branch located at 1 to 2 cm distal to the middle point of the forearm.(ABSTRACT TRUNCATED AT 250 WORDS)     

Processing of tactile spatial information with crossed fingers.

The erroneous perception of 2 objects when 1 object is touched with crossed fingers has been explained as an inability of the brain to correctly perceive the crossed fingers' positions. This account was examined in Exp I, in which the perceived position of stimuli touching the crossed fingers was mapped in 16 adult volunteers. Crossing the 3rd finger over the 4th displaced the perceived stimulus position counterclockwise; crossing the 3rd under the 4th displaced perceptions clockwise. In Exp II, perceived positions among 6 adults were found to fit a model of tactile saturation past the point of the functional range of action of the fingers. It is concluded that tactile stimuli are always perceived as if fingers were uncrossed and that spatial mapping is present only within the functional range of finger excursion. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posterior interosseous free flap: various types

The posterior interosseous artery is located in the intermuscular septum between the extensor carpi ulnaris and extensor digiti minimi muscles. The posterior interosseous artery is anatomically united through two main anastomoses: one proximal (at the level of the distal border of the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous artery joins the anterior interosseous artery to form the distal anastomosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses between the anterior and the posterior interosseous arteries at the level of the wrist. The flap is not reliable whenever there is injury to the distal forearm or the wrist. To circumvent this limitation and to increase the versatility of this flap, we have refined its use as a direct flow free flap. The three types of free flaps used were (1) fasciocutaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described are 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 fasciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 sensory flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The length of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and the external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.     

Flexor carpi radialis tendinitis. Part I: Operative anatomy

The anatomical characteristics of the flexor carpi radialis tendon, the tendon sheath, the tunnel boundaries, and the adjacent structures were examined in twenty-five adult cadaveric specimens. Transverse and sagittal sections of the wrist and forearm, tenograms, and histological sections of the tendon were made from two additional specimens each. The musculotendinous portion of the flexor carpi radialis tendon begins an average of fifteen centimeters (range, twelve to seventeen centimeters) proximal to the radiocarpal joint; the muscular fibers end an average of eight centimeters (range, six to nine centimeters) proximal to the wrist. The synovial sheath extends from the origin to the insertion. The tendon enters a fibro-osseous tunnel at the proximal border of the trapezium and is separated from the carpal canal by a thick septum that functions, at its distal border, as a pivot point for the flexor pollicis longus. Within the tunnel, the tendon occupies 90 per cent of the available space and is in direct contact with the slightly roughened surface of the trapezium. The tendon lies within a few millimeters of the distal aspect of the radius, the scaphoid tubercle, the scaphoid-trapezium-trapezoid joint, and the carpometacarpal joint of the thumb. In most patients, the flexor carpi radialis tendon is inserted at three locations. A small slip is connected to the trapezial crest or tuberosity; 80 per cent of the remaining tendon is inserted on the base of the second metacarpal and 20 per cent, on the base of the third metacarpal. The deep palmar arch is located two to three millimeters distal to the insertion of the tendon.     

3 anatomical observations of a right subclavian artery originating from the aortic arch (arteria lusoria)

1. The dissection of 223 subjects has revealed 3 cases of A. lusoria (1.06%). In all these cases, the A. lusoria was the last branch of the aortic arch. 2. X-ray pictures were taken after injection of radio-opaque substance to elicit the topographical relations of A. lusoria with esophagus. 3. There were only small variations in the calibre and in the way of its branches. Right common carotid artery directly arose from the aortic arch. 4. The three Aa. lusoriae crossed the dorsal face of esophagus between the 4th and 2nd cervical vertebrae where they provoked at neat natch. 5. In one case, there was a marked narrowing at the origin of the artery. In another case, there was an initial widening of the artery. 6. Histological examination of the arterial wall from the portion between oesophagus and vertebral column demonstrated a decrease in number of elastic fibres towards the column. 7. In all cases, there was around A. lusoria a normal Ansa subclavia from the sympathetic trunk. 8. In one case, recurrent nervus were topographically normal on both sides. In both other cases, the right recurrent nerve did not pass under the right subclavian artery but went directly to the larynx without touching the right inferior thyroid artery and its branches.     

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It is accepted that the ulnar artery forearm flap is dependent on the integrity of the palmar arches for ulnar arterial backflow and the patency of both radial and ulnar arteries. A patient is presented who demonstrates the successful use of the ulnar artery forearm flap supplied by the dorsal carpal arch via the dorsal branch of the ulnar artery. In this patient, the ulnar artery was damaged distal to the dorsal branch of the ulnar artery. A distally based ulnar forearm was dissected up to the dorsal branch of the ulnar artery and pivoted around this branch. This flap survived completely with no postoperative problem.     

The effects of training specific mnemonics on the metamnemonic efficiency of retarded children

On examination of the thumbs of 20 dissected preparations of ligaments and joints, of ten dry skeletons and of a number of living hands, apoposition (from apo = away from) was distinguished as a position in which the first carpometacarpal joint is fully abducted and laterally rotated and in which one or both distal joints of the thumb are flexed. Apoposition is commonly used in writing and it has a specific osteoligamentous basis for its stability: (1) a Y-shaped intermetacarpal ligament is attached by two crura to the base of the second metacarpal bone and by a common stem to the first metacarpal. Together with the palmar and dorsal oblique ligaments it becomes taut at abduction and establishes thereby a fixed center for the circumduction. Stability is enhanced as the circumduction takes place in the radial flat part of the joint away from the center; (2) of the two palmar prominences of the head of the first metacarpal bone the radial is the larger. At 25-30 degrees flexion in the metacarpophalangeal joint the prominence fits into an excavation on the base of the proximal phalanx in a manner which together with the ulnar collateral ligament locks the joint against mutual abduction and lateral rotation, and (3) the radial part of the trochlea of the interphalangeal joint is larger than the ulnar and secures, together with the ulnar collateral ligament, the joint against a radial luxation. Apoposition does not require activity of the thumb muscles; it is brought about by applying an external force to the ulnar side of the thumb and it is checked by ligaments and the shape of the joints.     

Anterior interosseous nerve syndrome presenting with pronator teres weakness: a case report

Anterior interosseous nerve syndrome (AINS) has been well described. A key muscle to examine clinically and on electromyography is the pronator teres, as this can differentiate between forearm and more proximal entrapment sites. We present a case of AINS with marked weakness and denervation of pronator teres. At operation the anterior interosseous nerve gave rise to the nerve to pronator teres and was entrapped by a fibrous band from the deep head of pronator teres.     

Surgical anatomy of the internal thoracic artery

BACKGROUND: The internal thoracic artery (ITA) has become increasingly important in coronary artery bypass grafting due to the excellent long-term results. This study reviews its anatomic characteristics. METHODS: The ITAs of 100 cadavers were examined and their origin, relation to the phrenic nerve, presence of lateral costal branch; origin of pericardiacophrenic arteries, length, level and type of ITA termination, relation with the transverse muscle of thorax, collateral parietal branches, and distance between the ITA and sternal margins were studied. RESULTS: The ITA was present in all cases, originating directly from the subclavian artery or from a common trunk with other arteries. Its length was 20.4 cm on average, and the most frequent level of termination was at the sixth intercostal space, existing as a bifurcation in 93% and as a trifurcation in 7%. The pericardiacophrenic artery originated from the ITA in 89%. The lateral costal branch was present in 15% of the cases. The ITA was covered by the transverse muscle of the thorax for 7.5 cm (average) and was crossed anteriorly by the phrenic nerve in 70.0%. CONCLUSIONS: Information provided by this study may contribute to knowledge of its anatomic characteristics and in turn help prevent complications in ITA dissections.     

Vascular supply of the unsheathed segment of the extensor tendons of the 2d to 5th fingers of the dorsum of the hand]

The dorsal approach to the metacarpal bones is through the peritendinous connective tissue of the extensor tendons. Knowledge of the vascular supply of the distal parts of these tendons, between the distal end of the tendon sheath and the tendon's osseous insertion is important, especially with respect to atraumatic technique. The course and distribution of the vessels to the extensor tendons II-V were investigated. Superficial and deep layers of connective tissue were found to contain blood vessels. The superficial vessels reach the dorsal aspect of the extensor tendon, originating from subcutaneous arteries and the large arteries of the hand. The deep vessels reach the lateropalmar aspect of the tendons and originate from the peritendinous muscular arteries. Vessel distribution suggests a direct relationship between the number of nourishing arteries and the tendon surface area. The vascular supply to the unsheathed parts of the extensor tendons shows morphological adaptations to differential mechanical stress during tendon excursion.     

The cutaneous innervation of the palm: an anatomic study of the ulnar and median nerves

Twenty-five fresh-frozen cadaveric hands without obvious deformity were dissected using 3.5x loupe magnification. Median and ulnar nerves were identified in the proximal forearm and dissected distally to the midpalm. Cutaneous branches of median and ulnar nerves were described relative to an incision for carpal tunnel release. The palmar cutaneous branch of the median nerve was present in all 25 specimens. In a single specimen, the palmar cutaneous branch of the median nerve was isolated as it crossed the incision, and in another two specimens, the terminal branches of the nerve were identified at the margin of the incision. In 4 hands, a classic palmar cutaneous branch of the ulnar nerve was found an average of 4.9 cm proximal to the pisiform. In 10 specimens, a nerve of Henle arose an average of 14.0 cm proximal to the pisiform and traveled with the ulnar neurovascular bundle to the wrist flexion crease. In 24 specimens, at least one-usually multiple-transverse palmar cutaneous branch was identified originating an average of 3 mm distal to the pisiform within Guyon's canal. The origin and destination of these nerves was highly variable. In 16 specimens, an incision in the axis of the ring finger would likely have encountered at least one branch of the ulnar-based cutaneous innervation to the palm. Cutaneous branches of the ulnar nerve would be expected to cross the line of dissection frequently during open carpal tunnel release. Decreased levels of discomfort in patients undergoing endoscopic and subcutaneous types of carpal tunnel release may be in part due to the preservation of the crossing cutaneous nerves with these procedures.     

The anatomical basis of the vascularized pronator quadratus pedicled bone graft

The vascular supply of the pronator quadratus was studied in 25 cadaveric dissections following coloured latex injections. This showed that the main blood supply of the pronator quadratus came from the anterior interosseous artery. There was, however, a rich anastomosis between the branches of the anterior interosseous artery and those of the radial and ulnar arteries. It was possible to raise a corticocancellous bone graft from the anterior surface of the radial styloid on a pedicle of the lower fibres of the pronator quadratus muscle. This muscle pedicle had a constant branch of the anterior interosseous artery which vascularized the bone graft. Such a vascularized pedicled bone graft may be useful in the treatment of non-union of the scaphoid and Kienb?ck's disease.