Estudo anatômico do túnel radial e suas implicações nas síndromes compressivas

Objective  The purpose of the present study was to analyze the structures in the radial tunnel that can cause posterior interosseous nerve entrapment.

Methods  A total of 30 members of 15 adult cadavers prepared by intra-arterial injection of a 10% solution of glycerol and formalin were dissected. All were male, belonging to the laboratory of anatomy of this institution.

Results  The branch for the supinator muscle originated from the posterior interosseous nerve in all limbs. We identified the Frohse arcade with a well-developed fibrous constitution in 22 of the 30 dissected limbs (73%) and of muscular constitution in 8 (27%). The distal margin of the supinator muscle presented fibrous consistency in 7 of the 30 limbs (23.5%) and muscular appearance in 23 (76.5%). In the proximal margin of the extensor carpi radialis brevis muscle, we identified the fibrous arch in 18 limbs (60%); in 9 (30%) we noticed the arcade of muscular constitution; in 3 (10%) there was only the radial insertion, so that it did not form the arcade.

Conclusion  The Frohse arcade and the arcade formed by the origins of the extensor carpi radialis brevis are normal anatomical structures in adult cadavers. However, from the clinical point of view, these structures have the potential to cause entrapment of the posterior interosseous nerve.

Riché-Cannieu Anastomosis: Structure, Function, and Clinical Significance

Objective  To define the anatomy pattern and the incidence of Riché-Cannieu anastomosis, that is, median and ulnar communication in the palmar aspect of the hand.

Materials Methods  A total of 80 anatomical dissections were performed on 60 hands of 30 cadavers from 1979 to 1982, and on 20 hands from 2012 to 2015. All of these procedures were performed at the Department of Anatomy of our institution. The incidence of Riché-Cannieu anastomosis and the innervation of the thenar muscles were studied.

Results  Riché-Cannieu anastomosis was identified in every dissected hand (100%). The extramuscular Riché-Cannieu anastomosis was recorded in 57 hands, and the intramuscular, in 19 hands. The association of extra- and intramuscular Riché-Cannieu anastomoses occurred in four hands. The ulnar component always originated from the deep branch. The anastomotic branch arising from the median nerve originated from the motor thenar branch (recurrent branch) of the median nerve in most of the observations. The median-ulnar double innervation only to the deep head of the flexor pollicis brevis was identified in 29 of 80 hands. The double innervation only of the superficial head of the flexor pollicis brevis was found in 13 hands. In 12 hands, the deep head of the flexor pollicis brevis was absent. The double innervation of the superficial and deep heads of the flexor pollicis brevis occurred in 14 hands. The oblique head of the adductor pollicis received double innervation in 12 hands. The deep head of the flexor pollicis brevis and the oblique head of adductor pollicis were doubly-innervated in nine hands. The transverse head of the adductor pollicis received double innervation in two hands. Double innervation of the deep head of the flexor pollicis brevis and the transverse head of the adductor pollicis were found in one hand.

Conclusion  According to the present study, Riché-Cannieu anastomosis should be considered a normal anatomical neural connection, not an anatomical variation. Knowledge of this anastomosis is essential because the presence of such neural communication may result in confusing clinical, surgical, and electromyographic findings in cases of median or ulnar damage or entrapment.

Anatomical Study of Innervation of the Supinator Muscle to Reinnervate the Posterior Interosseous Nerve

Objective  The purpose of this anatomical study was to analyze the possibility of transferring radial nerve branches to the supinator muscle to reinnervate the posterior interosseous nerve (PIN) originating from the C7–T1 roots.

Methods  Thirty members of 15 cadavers, all male, prepared with an intra-arterial glycerol and formaldehyde solution injection, were dissected.

Results  All dissected limbs presented at least one branch intended for the superficial and the deep heads of the supinator muscle. These branches originated from the PIN. A branch to the supinator muscle, proximal to the arcade of Frohse, was identified in six members. In addition, 2 and 3 branches to the supinator muscle were found in 11 and 4 members, respectively. In two limbs, only one branch detached from the PIN, but it duplicated itself proximal to the arcade of Frohse. Seven limbs had no branches to the supinator muscle at the region proximal to the arcade of Frohse. The branches destined for the supinator muscle were sectioned at the neuromuscular junction for connection with no tension to the PIN. The combined diameter of the branches for the supinator muscle corresponded, on average, to 53.5% of the PIN diameter.

Conclusion  The radial nerve branches intended for the supinator muscle can be transferred, with no tension, directly to the PIN to restore thumb and finger extension in patients with C7–T1 brachial plexus lesions.

Anatomical study of the transfer of flexor digitorum superficialis nerve branch of median nerve to restore wrist extension and forearm pronation

Objective

To analyze the anatomical variations of the innervation of the flexor digitorum superficialis muscle and to determine if the branch of the median nerve that supply this muscle is connected to the branches to the extensor carpi radialis brevis and the pronator teres muscles, without tension, and how close to the target-muscles the transfer can be performed.

Methods

Fifty limbs of 25 cadavers were dissected to collect data on the anatomical variations of the branches to the flexor digitorum superficialis muscle.

Results

This muscle received innervation from the median nerve in the 50 limbs. In 22 it received one branch, and in 28 more than one. The proximal branch was identified in 22 limbs, and in 12 limbs it shared branches with other muscles. The distal branch was present in all, and originated from the median nerve as an isolated branch, or a common trunk with the anterior interosseous nerve in 3 limbs, and from a common trunk with the flexor carpi radialis muscle and anterior interosseous nerve in another. It originated distally to the anterior interosseous nerve at 38, in 5 on the same level, and in 3 proximal to the anterior interosseous nerve. In four limbs, innervation came from the anterior interosseous nerve, as well as from the median nerve. Accessory branches of the median nerve for the distal portion of the flexor digitorum superficialis muscle were present in eight limbs.

Conclusion

In 28 limbs with two or more branches, one of them could be connected to the branches to the extensor carpi radialis brevis and pronator teres muscles without tension, even during the pronation and supination movements of the forearm and flexion-extension of the elbow.

Circular saw misuse is related to upper limb injuries: a cross-sectional study

OBJECTIVES

Machinery injuries account for a substantial share of traumatic upper limb injuries (TULIs) affecting young active individuals. This study is based on the hypothesis that there is an important relationship between the improper use of power saws and TULIs. The aim of the study is to assess the prevalence and epidemiology of TULIs caused by power saws and determine the risks related to power saw use.

METHODS

A cross-sectional evaluation of medical records from a two-year period was performed. Patients sustaining TULIs related to power saws were analyzed. Data on the epidemiology, site of injury, mechanism of trauma, technical specifications of the tool, cutting material, personal protective equipment, time lost and return to work were obtained.

RESULTS

A database search retrieved 193 TULI records, of which 104 were related to power saws. The majority of patients were male (102/104; 98.1%), right-handed (97/104; 93.3%), and manual workers (46/104; 44.2%), with an average age of 46.8 years. The thumb was the most frequently injured site (32/93; 34.4%). Most of the injuries were caused by manual saws (85/104; 81.7%), and masonry saws accounted for 68.2% (58/85) of the cases. Masonry saws improperly used for woodwork resulted in 86.2% (50/58) of the injuries. TULI caused by masonry saws was 5 times higher in manual workers than in other patients. In addition, masonry saws had a risk of kickback 15 times higher than that of other saws, and the risk of injury increased by 5.25 times when the saws were used improperly for wood cutting.

CONCLUSIONS

The profile of TULIs related to power saws was demonstrated and was mainly associated with manual saws operated by manual workers that inappropriately used masonry saws for woodworking.

TRANSFER OF NERVE BRANCHES OF THE FLEXOR CARPI RADIALIS TO THE POSTERIOR INTEROSSEOUS NERVE

Objective:

The objective of this paper was to study the anatomical variations of the flexor carpi radialis muscle (FCR) and determine in cadaver limbs whether the FCR nervous branch can be connected to the posterior interosseous nerve (PIN) without tension and how close to the target muscles the transfer can be performed.

Method:

Thirty cadaveric upper limbs were dissected.

Results:

The FCR received exclusive innervation of the median nerve, distally to the intercondylar line of the humerus. In 5 limbs, an isolated branch was found and in 25, a common trunk with other nervous branches occurred. We investigated whether the branch for the FCR was long enough to be transferred to the PIN. The diameter of the nerve branch for the FCR corresponded on average to 50% of the PIN.

Conclusion:

In 12 limbs, the branch destined to the FCR could be connected to the PIN, distally to the nerve branches to the supinator muscle even during the movements of the forearm and the elbow. In 18 specimens, it was necessary to mobilize the PIN for this innervation. Level of Evidence IV, Case Series.

Anterior interosseous nerve: anatomical study and clinical implications

Objective

The goal of this study was to describe anatomical variations and clinical implications of anterior interosseous nerve. In complete anterior interosseous nerve palsy, the patient is unable to flex the distal phalanx of the thumb and index finger; in incomplete anterior interosseous nerve palsy, there is less axonal damage, and either the thumb or the index finger are affected.

Methods

This study was based on the dissection of 50 limbs of 25 cadavers, 22 were male and three, female. Age ranged from 28 to 77 years, 14 were white and 11 were non-white; 18 were prepared by intra-arterial injection of a solution of 10% glycerol and formaldehyde, and seven were freshly dissected cadavers.

Results

The anterior interosseous nerve arose from the median nerve, an average of 5.2 cm distal to the intercondylar line. In 29 limbs, it originated from the nerve fascicles of the posterior region of the median nerve and in 21 limbs, of the posterolateral fascicles. In 41 limbs, the anterior interosseous nerve positioned between the humeral and ulnar head of the pronator teres muscle. In two limbs, anterior interosseous nerve duplication was observed. In all members, it was observed that the anterior interosseous nerve arose from the median nerve proximal to the arch of the flexor digitorum superficialis muscle. In 24 limbs, the branches of the anterior interosseous nerve occurred proximal to the arch and in 26, distal to it.

Conclusion

The fibrous arches formed by the humeral and ulnar heads of the pronator teres muscle, the fibrous arch of the flexor digitorum superficialis muscle, and the Gantzer muscle (when hypertrophied and positioned anterior to the anterior interosseous nerve), can compress the nerve against deep structures, altering its normal course, by narrowing its space, causing alterations longus and flexor digitorum profundus muscles.

Bone marrow-derived mesenchymal stem cells versus adipose-derived mesenchymal stem cells for peripheral nerve regeneration

Studies have confirmed that bone marrow-derived mesenchymal stem cells (MSCs) can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs (BMSCs) is an invasive and painful process and the yield is very low. Therefore, there is a need to search for other alterative stem cell sources. Adipose-derived MSCs (ADSCs) have phenotypic and gene expression profiles similar to those of BMSCs. The production of ADSCs is greater than that of BMSCs, and ADSCs proliferate faster than BMSCs. To compare the effects of venous grafts containing BMSCs or ADSCs on sciatic nerve injury, in this study, rats were randomly divided into four groups: sham (only sciatic nerve exposed), Matrigel (MG; sciatic nerve injury + intravenous transplantation of MG vehicle), ADSCs (sciatic nerve injury + intravenous MG containing ADSCs), and BMSCs (sciatic nerve injury + intravenous MG containing BMSCs) groups. Sciatic functional index was calculated to evaluate the function of injured sciatic nerve. Morphologic characteristics of nerves distal to the lesion were observed by toluidine blue staining. Spinal motor neurons labeled with Fluoro-Gold were quantitatively assessed. Compared with sham-operated rats, sciatic functional index was lower, the density of small-diameter fibers was significantly increased, and the number of motor neurons significantly decreased in rats with sciatic nerve injury. Neither ADSCs nor BMSCs significantly improved the sciatic nerve function of rats with sciatic nerve injury, increased fiber density, fiber diameters, axonal diameters, myelin sheath thickness, and G ratios (axonal diameter/fiber diameter ratios) in the sciatic nerve distal to the lesion site. There was no significant difference in the number of spinal motor neurons among ADSCs, BMSCs and MG groups. These results suggest that neither BMSCs nor ADSCs provide satisfactory results for peripheral nerve repair when using MG as the conductor for engraftment.

Flexor Pollicis Brevis Muscle. Anatomical Study and Clinical Implications

Introduction:

This paper reports anatomical study of nature, incidence, innervation and clinical implications of Flexor Pollicis Brevis muscle (FPB).

Material and Methods:

The anatomical dissection of 60 limbs from 30 cadavers were performed in the Department of Anatomy of Medical School of Catholic University of São Paulo.

Results:

The superficial head of FPB has been innervated by the median nerve in 70% and in 30% it had double innervation. The deep head of FPB were absent in 14%, in 65%, occurred a double innervation. In 17.5% by deep branch of ulnar nerve and in 3.6% by recurrent branch of median nerve.

Conclusion:

The pattern of innervation more frequent in relationship to the flexor pollicis brevis muscle and should be considered as a normal pattern is that superficial head receives innervation of branches of median nerve and the deep head receives innervation of ulnar and median nerve.

EVALUATION OF THE KNOWLEDGE ON COST OF ORTHOPEDIC IMPLANTS AMONG ORTHOPEDIC SURGEONS

Objective:

To determine the knowledge of Brazilian Orthopedic Surgeons on the costs of orthopedic surgical devices used in surgical implants.

Methods:

A questionnaire was applied to Brazilian Orthopedic Surgeons during the 46^th Brazilian Congress on Orthopedics and Traumatology.

Results:

Two hundred and one Orthopedic Surgeons completely filled out the questionnaire. The difference between the average prices estimated by the surgeons and the average prices provided by the supplier companies was 47.1%. No differences were found between the orthopedic specialists and other subspecialties on the prices indicated for specific orthopedic implants. However, differences were found among orthopedic surgeons who received visits from representatives of implant companies and those who did not receive those visits on prices indicated for shaver and radiofrequency device. Correlation was found between length of orthopedic experience and prices indicated for shaver and interference screw, and higher the experience time the lower the price indicated by Surgeons for these materials.

Conclusion:

The knowledge of Brazilian Orthopedic Surgeons on the costs of orthopedic implants is precarious. Reduction of cost of orthopedics materials depends on a more effective communication and interaction between doctors, hospitals and supplier companies with solid orientation programs and awareness for physicians about their importance in this scenario.Level of Evidence III, Cross-Sectional Study.

Peripheral nerve regeneration with conduits: use of vein tubes

Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.