The communicating branches between the sural and superficial peroneal nerves in the foot: a review of 55 cases.

The rich sensory innervation of the ankle and foot is manifest through the numerous communicating branches linking the neural trunks, particularly the superficial peroneal and sural nerves on the anterolateral aspect of the hindfoot. The 35 communicating branches seen in 55 dissections (58%) were proximal in half of the cases, lying in the malleolar and lateral tarsal regions, and distal in the other half, in the metatarsal region. The communicating branch was straight in 25 cases and curved in 11. The average distances of the communicating branch from the crest of the lateral malleolus and the tubercle of the 5th metatarsal was 4.7 and 4.1 cm, but there was a wide range of values. We believe that stretching of the proximal communicating branch during forced inversion of the ankle and/or foot or during fractures of the calcaneus or direct injury in surgical approaches or arthroscopy of the ankle may lead to unexplained pre- and submalleolar pain. Advances in modern imaging may allow recognition of these branches and guidance of infiltration and even neurolysis in cases of failure of conservative treatment.

Anatomic and biometric study of the acromioclavicular joint by ultrasound.

The aim of this study was to describe the normal ultrasound anatomy of acromioclavicular joint (ACJ) and to establish ultrasound biometric criteria of this joint. Thirty healthy volunteers (16 men, 14 women) underwent a bilateral ultrasound examination of the ACJ in both planes (superior, anterosuperior) by two different observers. Six measurements were evaluated on the ACJ. The morphological appearance was also studied. Five morphological types of the ACJ were identified. No significant biometric difference was found between the observers, the planes, the dominant and the non-dominant side, and between men and women (except for the deep joint space distance). However, the variability of the ACJ made this biometric study difficult. The maximum distance between the joint capsule and the deep joint space through the superior plane, seemed to be a reproducible measurement with the best confidence interval.

The inferior hypogastric plexus (pelvic plexus): its importance in neural preservation techniques.

The progress in the surgery of male neurological cancers relies on the anatomico-surgical approach to the pelvic neural structures. The objective of our study was to provide a better understanding of the inferior hypogastric plexus (IHP) and its anatomical relationships in order to spare it during radical prostatectomy. Fifteen male formalin-preserved cadavers which had no sub-umbilical scar were used. In five subjects, the superior hypogastric plexus (SHP) and the pre-sacral plexus were displayed then the IHP and its sacral afferents (pelvic splanchnic nerves or erector nerves of Eckhardt) were dissected out. Serial sections of the IHP were then studied in ten subjects. This allowed its identification on certain imaging sections obtained in pelvic tumor pathology and these made up the "reference cuts". The IHP lies within a fibro-fatty plate which is flat, rectangular, sub-peritoneal, sagittal and symmetrical. It arises at the level of the intersection between the vas deferens and the terminal pelvic ureter and follows the postero-lateral aspect and circumvolutions of the seminal vesicle, with which there is a plane of surgical cleavage. The seminal vesicle is, therefore, an essential landmark for this neural structure. The plane of this cleavage may be used in pelvic cancer surgery. The safest technical means of respecting sexual function and the integrity of the IHP is to keep it at a distance. The preservation of a lateral layer of the seminal vesicle is probably a method of limiting these complications as long as this does not conflict with the oncological clearance. An irregular communicating branch was found in one of five cases between the IHP, the sacral plexus and the pudendal nerve. This communicating branch lay immediately behind the intersection between the vas deferens and the ureter in the sacral concavity. It overhangs the IHP in the seminal vesicle. Impotence remains a frequent complication after radical prostatectomy. The methods of neural preservation at the prostatic apex are known but neural preservation should also be carried out posteriorly at the lateral pole of the seminal vesicle. The possibility of posterior neural preservation may be assessed pre-operatively by study of the "reference sections". The cleavage plane between the seminal vesicle and the IHP may be used intra-operatively to spare the IHP. The cavernous nerve in particular emerges at the antero-inferior border of the IHP before running along the postero-lateral aspect of the prostate. It therefore passes in contact with the seminal vesicle and may as a result be injured during radical prostatectomy with vesiculectomy. A proximal communicating branch between the IHP and the pudendal nerve is irregular. Such communicating branches may explain a better recovery of sexual function in curative neurological cancer surgery. The essential relationship of the IHP is with the seminal vesicle. The two are in tight contact and the seminal vesicle has a true plane of surgical cleavage with IHP. The risk of injuries to the posterior erectile mechanisms can be reduced either by using the cleavage plane between the IHP and seminal vesicle or by leaving a layer of the seminal vesicle when the oncological conditions allow. During celio-surgery, the operator must be careful to retract the little bands of the seminal vesicle and divide the fibrous and vascular tracts which tighten during this maneuver. During an abdominal approach, dissection of the seminal vesicle takes place at the bottom of a real pit. The operator must carry out the division leaving a layer of the seminal vesicle in place rather than trying to extract all the seminal vesicle by placing the forceps blindly. This maneuver is naturally dependent on the oncological situation. The anatomical confirmation of a regular or irregular proximal or distal communicating branch between the IHP and the pudendal nerve is probably an explanation for the sometimes uncertain results of new techniques of neural preservation in curative cancer surgery.

Lumbar spinal ganglia enhancement after gadolinium chelate administration: a radio-histological correlation.

The aim of the present study was to assess the frequency of enhancement of lumbar spinal ganglia after Gadolinium chelate injection in patients without radiculopathy, and to correlate the enhancement with histology. This study is based on the analysis of MR lumbar examinations conducted on 18 patients without radicular symptoms, or previous surgery of the lumbar spine, or disease of the nervous system. The patients were imaged with a 1.5 T unit. Sagittal images were first obtained with a T1-weighted turbo spin-echo. Axial and sagittal images were then obtained with a T1-weighted turbo spin-echo, fat-saturated sequence after Gadolinium intravenous injection from the T12/L1 to the L5/S1 level. All 180 spinal ganglia demonstrated an important and homogeneous enhancement after Gadolinium injection. Four spinal ganglia obtained by dissection from four different fresh cadavers were studied by light microscopy to determine the potential relationship between contrast enhancement and presence and topography of vessels within the spinal ganglia. Vessels were particularly abundant at the peripheral zone of the spinal ganglia. The post-contrast enhancement of the spinal ganglia after Gadolinium administration has to be known and may be explained by the microvasculature pattern.

Origin and make up of the human sural nerve.

The dissection of 37 cadavers has shown that in only a third of cases, the sural nerve comes from the communication between the medial cutaneous nerve, derived from the tibial nerve, and the communicating branch of the lateral cutaneous nerve of the leg which comes from the lateral popliteal nerve. The communication is most often at the junction between the proximal two-thirds and distal third of the leg, on average 2 mm below the transverse crease of the popliteal fossa. The medial cutaneous nerve was absent in only one case. On the other hand, in 11 cases the lateral cutaneous nerve or its communicating branch was missing. In 12 cases without any anastomoses, the route of the sural nerve was followed by the medial cutaneous nerve of the leg in 9 cases and by the lateral cutaneous nerve in 3 cases. The majority of branches to the proximal half of the calf came from the lateral cutaneous nerve. In the lower part of the leg, the sural nerve and/or the medial cutaneous nerve gave numerous branches to the Achilles' tendon and to the integuments of the lateral aspect of the heel and lateral malleolus.

Thoracic outlet: anatomic correlation with MR imaging.

OBJECTIVE: The purpose of this report is to describe the normal MR anatomy of the thoracic outlet and its modification after postural maneuvers using an anatomic-MR imaging correlation. CONCLUSION: MR imaging appears to be a useful technique to study the thoracic outlet and its contents because of its excellent soft-tissue depiction and its multiplanar capabilities. T1-weighted images obtained in the sagittal plane clearly depicted the different compartments of the cervicothoracic-brachial junction. Hyperabduction maneuvers may have potential applications in the assessment of the thoracic outlet syndrome by showing the location of compression.

Radio-anatomic demonstration of the vertebral lumbar venous plexuses: an MRI experimental study.

The aim of this study was to provide a basis of knowledge of the anatomy of the venous plexuses in the lumbar spine both in anatomical slices and in MR images in order to help the analysis of these structures in MR images of living subjects. Four fresh cadaveric lumbar spines were studied after the injection of coloured gelatin mixed with gadolinium. The specimens were injected by an intraosseous technique. Axial and sagittal fat-saturated T1-weighted MR images were performed on the specimens. Thereafter, specimens were frozen and cut into 5-mm thick slices, three in the axial plane and one in the sagittal plane. All the components of the internal and external venous plexuses were identified on the MR images in correlation with the corresponding anatomic sections. The MR anatomy of the venous system of the lumbar spine is important as it has been implicated in many pathophysiological mechanisms and as it may also cause pitfalls in MR imaging.

Variations of the radial artery in man.

Variations of the radial artery are common in man. A high origin, due either to precocious bifurcation or to persistent duplication of the brachial artery, and the presence of a superficial dorsal ramus in the forearm suggest hemodynamic insufficiency of the axial vascular network allowing persistence of certain portions of the superficial system of the upper limb. Confusion of these unusual arteries with the subcutaneous veins may explain the accidental injection of drugs and distal necrosis of the limb. Knowledge of these variations may facilitate ascending catheterization of the cardiac cavities.

[The biphalangy of the thumb. General review of the literature]. / La biphalange du pouce. Revue générale de la littérature.

The thumb has only two phalanges whereas the other fingers present three. For two millennia, many anatomists tried to solve this riddle. Four different theories can be found in the review of literature, to explain what element misses in the radial column. In the first theory (Galen), the first metacarpal should be the proximal phalanx of the thumb. The particular ossification of the first metacarpal advocates for this theory. In the second theory (Sappey), the first metacarpal should result from the fusion between the true first metacarpal and the proximal phalanx of the thumb, and the proximal epiphysis should be constituted from both metacarpal and phalangeal parts. In the third theory (Paturet), the middle phalanx is thought to be missing. Apart morphological considerations, the main argument refers to symbrachydactyly, which consists in decreasing digital ray length (by reducing the middle phalanx), and usually affects digits excluding the thumb. In case the thumb is affected (in complex symbrachydactylies), the reduction concerns thus the first metacarpal, suggesting that the thumb middle phalanx has already disappeared. In the fourth theory (Pfitzner), the distal phalanx of the thumb should result from the fusion between the second and third phalanges of the thumb. This mechanism, named symphalangy, is well known in the foot, especially in the fifth toe, but also for the other toes, and even in the two ulnar fingers.

The blood supply of the deltoid muscle. Application to the deltoid flap technique.

The major ruptures of the rotators cuff point out the problem of their surgical repair. Various techniques are described in the literature, among them the deltoid flap technique, described by Apoil and Augereau. This technique points out the problem of a few cases of flap early necrosis (Saragaglia). We studied the deltoid arterial blood supply on 40 cadaveric shoulder, after coloured injection into the subclavian artery. Our study included 40 macroscopic and 15 radiographic observations. The thoracoacromial artery gave off two collaterals to the anterior part of the deltoid muscle. The first one, called the deltoid artery, ran into the anterior part of the deltoid, near the deltopectoral line. In 53%, it gave off a first superior collateral branch, which ran at 3 cm under the clavicle. The second one, called the acromial artery, ran deep to the anterior part of the deltoid muscle, near the clavicle and the acromion. The posterior circumflex humeral artery was the most important artery. It supplied the posterior and middle parts of the deltoid muscle. The anterior circumflex humeral artery supplied the anterior part of the deltoid muscle in 63%. In ten cases, we dissected a deltoid flap. In all the cases, the acromial artery was cut near the acromion. When the deltoid artery gives off its superior collateral branch, it was always cut. Then, this flap was only vascularized by its inferior aspect. These results show that the flap is located in a poorly supplied area. Thus, the flap necrosis could be explained by an insufficient anastomotic network. An operative technique modification could avoid this complication.

[Anesthesia and critical care for endovascular occlusion of ruptured intracranial aneurysms with electrically detachable coils]. / Anesthésie-réanimation pour occlusion endovasculaire des anévrismes intracrâniens rompus par des spires électriquement détachables.

The endovascular occlusion of ruptured intracranial aneurysms with electrically detachable coils is a therapeutic approach which seems to be a promising technique. General anaesthesia is considered as being the most adapted for its realisation, as its provides complete immobility and as controlled ventilation and extended monitoring offer optimal conditions for undelayed treatment of haemorrhagic and thromboembolic complications. The available equipment should be the same as that used for conventional surgical treatment of ruptured aneurysms. Anticoagulation is required to prevent thromboembolic complications during and after the procedure. Most teams administer heparin.

Viscoelastic properties of human arteries. Methodology and preliminary results.

In order to study the biomechanical properties of the arterial wall and to compare arteries with different histologic structures, we designed a device that allows testing of arterial segments under near-physiologic conditions. A hydrodynamic generator simulates systolo-diastolic pressures in an open loop. An intraarterial pressure sensor and a sonomicrometer connected to two piezoelectric crystals placed in diametric opposition on the arterial wall allow computer calculation of compliance, stiffness, midwall radial arterial stress, Young modulus, and incremental modulus for a given arterial segment at a given pressure setting. Seven healthy common carotid artery (CCA) segments and seven healthy (superficial) femoral artery (FA) segments were studied immediately after removal from brain-dead donors between the ages of 18 and 35 years. Histologic examination was performed to determine the density of elastic fibers in the arterial wall. Hysteresis was observed in all segments regardless of pressure settings. Compliance was greater and modulus values and stiffness were lower in CCA than in FA. No evidence of structural change was noted after testing in the circulation loop. These preliminary results open the way to a wide variety of applications for our hydrodynamic circulation loop. Experiments will be undertaken to compare the mechanical properties of arteries before and after cryopreservation.

[Retrograde percutaneous catheterization of the internal jugular vein in head injured patients]. / Cathétérisme percutané rétrograde de la veine jugulaire interne chez les traumatisés crâniens.

The monitoring of jugular venous oxygen saturation and lactate concentration in order to detect cerebral ischaemia or hyperaemia requires the insertion of a fibreoptic catheter into the upper bulb of the internal jugular vein. With dissection studies we have defined superficial anatomical landmarks which are constant and easily palpable, namely the mastoid process and the sternocleidomastoid muscle. This technique does not require a rotation of the head. The puncture site is located at the top of a triangular area between its sternal and clavicular insertions. At this site the jugular vein is rather superficial. This study reports our experience of the retrograde catheterisation of the jugular vein in twelve severely head injured patients.

[Hepato-diaphragmatic venous anastomosis (report of a case)]. / Anastomose veineuse hépatico-diaphragmatique (à propos d'un cas).

The authors are reporting an exceptional case of unexpected venous anastomosis between a right inferior diaphragmatic venous and a right hepatic venous discovered during a total hepatectomy before an orthotopic transplantation. Never described in the literature, this abnormality may be explained by the embryology of the transversum septum, junction of the hepatic draft and the draining tracts of the future diaphragm.

Antenatal differentiation of the human intervertebral disc.

To study the antenatal differentiation of the human intervertebral disc, the columns of forty eight embryos and fetuses were examined histologically. The primitive disc is composed of two structures: the notochord which shows a progressive expansion into the disc, and the fibro-cartilaginous perinotochordal disc. No histological sign of interaction between notochordal and perinotochordal cells, which may explain the notochordal expansion into the discs, was seen. On the other hand, the notochordal intervention in the cartilaginous differentiation of the inner zone is probable.

The supernumerary muscles of the leg: a report of two cases.

Two cases of supernumerary muscles of the leg reported, which were both inserted on the sides of the calcaneus. The accessory soleus m., adductor of the fore-foot, is a variation of the triceps surae which through hypertrophy on the medial side of the leg can become particularly problematic in athletes. The fourth peroneal m. abductor of the fore-foot, is considered to increase the stability of the ankle and is asymptomatic.

[Factors in the stabilization of the ulnar head]. / Les facteurs de stabilisation de la tête ulnarienne.

The authors studied the stability of the ulnar head by dissections of the radio-ulnar joint and experimental ligamentous removals in 150 specimens. They emphasize the importance of the tendon of the extensor carpi ulnaris and medial collateral ligament tightened by Kuhlmann's sling which firmly apply the ulnar head against the anterior edge of the sigmoid potch of the radius. Transsection of the separate fibro-osseous tunnel of the extensor carpi ulnaris with forward creeping of the tendon out of its groove enlarges the size of the gap between extensor carpi ulnaris and extensor digiti quinti; if in addition both fibro-cartilaginous disk and medial collateral ligament are torn, the ulnar head dislocates dorsally. Such a displacement can be obtained by full supination following forced pronation. The volar dislocation of the ulnar head occurs more rarely; it might be caused by insufficient extensor carpi ulnaris and ruptured fibro-cartilaginous disk and yielded by shallow sigmoid notch and blunt anterior border. So muscular structures avoid dorsal displacement of the ulnar head actively whereas only fibro-osseous structures passively prevent from anterior displacement.