Treatment of carpal tunnel syndrome consists in decompression of the median nerve by section of the flexor retinaculum. Usually, this surgery improves the disease with disappearance of the symptoms. However, some painful sequelae may remain such as painful discharges, paresthesiae or permanent anesthesia of the base of the thumb or of the scar related to an injury of the palmar cutaneous branch of the median nerve (PCBm). This study was performed to define the accurate emergence and the anatomic characteristics of this nerve in relation to stable landmarks. Moreover, it assessed the importance of the visual identification of the branch during section of the flexor retinaculum. Thirty-five hands were dissected under macroscopic examination and under magnification of the thinnest branches. Measurements were performed with a caliper and the forearm in supination. Determination of the bistyloid line showed variability in the location of the distal wrist crease. Thus, it could not be used as a landmark to locate the PCBm. The palmar cutaneous branch is the distal collateral branch of the median nerve in the forearm. It emerges on its radial side, on average 44.3 mm before the bistyloid line. It courses in line with the third finger and perforates the antebrachial aponeurosis about 5.7 mm from the bistyloid line. This emergence can be located in the palm, where it can be injured if the incision is performed in line with the third finger. The PCBm usually ends in the palm by division into two or three branches. The lateral branch supplies the skin of the thenar eminence while the medial, usually shorter branch supplies the midline part of the palm. This study has shown the importance of performing the cutaneous incision in line with the fourth finger to avoid injury to the PCBm.

The aim of this study was to specify certain anatomic features of the gracilis m. with a view to the use of muscular or myocutaneous flaps. It was based on dissection of 84 gracilis muscles in 42 subjects as well as selective injection of the main pedicle of 20 muscles. This established the following points: 1) The arterial supply is abundant, consisting of several pedicles reaching the muscle on its deep aspect. The main neurovascular pedicle arises from the deep vessels of the thigh, via either the a. of the adductors (73%), the medial circumflex a. (19.2%) or as a double supply from both arteries (7.7%); 2) The cutaneous vascularisation over the gracilis m., derived from the solitary main pedicle, is inconstant. In 20 injections, it was satisfactory in 11 cases, poor in 5 and absent in 4; 3) The distal tendon of the gracilis m. is closely related to the posterior branch of the saphenous n. to the leg, which it crosses in an elongated X; 4) A simple method of calculation based on the distance between the upper border of the pubis and the medial femoral epicondyle allows quite precise determination of the point of entry of the main pedicle into the gracilis m. 5) Complete dissection of the main pedicle adds to the available length of the muscle flap.

New techniques to stabilize and correct the thoracic and lumbar spine have been developed in recent years. In view of the wide variety and complexity of fixation devices, the optimum configuration of spinal instrumentation systems needs to be defined. Linear and angular measurements of both vertebral pedicles were made in ten complete thoracic and lumbar cadaveric spines using callipers and a goniometer. The vertical interpedicular distance gradually increased along the spine up to L5. The transverse interpedicular distance was larger at both ends of the spine. Pedicular height gradually increased from T1 to L5, plateauing between T3 and T9, being widest at the thoracolumbar junction. Pedicular width was greatest at the three junctional regions of the spine. The sagittal pedicular angle decreased along the length of the spine to zero at L5. The transverse pedicular angle decreased from T1 to T12 and then increased to L5. Of the pedicular measurements only width limits the diameter of fixation screws. The vertical interpedicular distance determines the distance between the holes of plates, while the length of the transfixator is related to the transverse interpedicular distance. The pedicular angles enable triangulation of screws and determine the stability of the fixation.

The dissection of 100 external jugular veins in 50 cadavers was the object of this anatomic study. A certain number of notions concerning the afferent veins, the mode of termination and the valvular system of this vessel were defined. 1) Afferent veins. Along its pathway toward the deep venous system, the external jugular vein successively received: the transverse cervical vein in 88 cases (88%), usually opposite the intersection of the external jugular vein with the dorsal border of the sterno- cleidomastoid muscle; the suprascapular vein in 47 cases (47%); the anterior jugular vein in 46 cases (46%); the cervical vein or anastomosis with the latter in 13 cases (13%). 2) Mode of termination. Forty-three subjects presented a symmetric mechanism. 100 anastomoses can be classed into three types: in 60 cases (60%), the external jugular vein flowed into the jugulo-subclavian venous confluence; in 36 cases (36%), in to the subclavian vein at a distance from its junction with the internal jugular vein; in 4 cases (4%) in to the trunk of the internal jugular vein. 3) Study of the valves. There were studied in 25 subjects (50 external jugular veins). The valves were found in the ostial and paraostial position in 49 out of 50 veins.

No abstract