Sensory nerve supply of the distal radio-ulnar joint with regard to wrist denervation.

The objective of this study was to determine the precise departure points of the articular branches innervating the distal radio-ulnar joint from the anterior and posterior interosseous nerves. The study sample consisted of 116 upper limbs from adult human cadavers. The articular branches were prepared under the dissection microscope to take measurements using the radial styloid process as point of reference. The articular branch departed from the anterior interosseous nerve at a mean distance of 2.9 cm proximal to the styloid for a radius length of 20.5 cm, and 3.7 cm for a radius length of 26.5 cm, respectively. For the posterior interosseous nerve, the departure point was at a mean distance of 3.1 cm (radius length of 20.5 cm) and at 4.0 cm (radius length of 26.5 cm). Apart from a single branch from the posterior interosseous nerve, all articular branches were located distal to the proximal border of the pronator quadratus. Results indicate that wrist denervation from the volar approach, if performed at the proximal border of the pronator quadratus, or from the dorsal approach at a distance of 4.8 cm (for a radius length of 20.5 cm) or 6.2 cm (for a radius length of 26.5 cm) proximal to the radial styloid process, will eliminate the nerve supply to the distal radio-ulnar joint in the majority of cases.

Minimally invasive approach to the radial nerve--A new technique.

PURPOSE: To describe a minimally invasive approach to find the radial nerve (RN) simply and safely by tracing the posterior antebrachial cutaneous nerve (PACN) without damaging muscles, using only the surgeon's hand to define a window for the skin incision. BACKGROUND: Although it is absolutely necessary to locate the radial nerve during osteosynthesis of the humerus, the literature lacks guidelines on how to do so. METHODS: We have dissected the upper extremities of 54 adult human cadavers, embalmed using Thiel's method. After the PACN was identified in a defined space, its course was traced proximally by incising the lateral intermuscular septum (LIS) of the upper arm and thereby reaching the radial nerve (RN). Subsequently, using the lateral epicondyle (LE) of the humerus as a reference point, the distances to the points where the PACN perforated the LIS, and where the RN was identified, were measured. These individual data were related to the total length of the humerus. RESULTS: The results indicate that with this approach and without harming musculature, the RN can be reached by tracing the PACN at a height of 11.1-13.0 cm (females) and 11.9-14.0 cm (males) starting from the LE. CONCLUSION: Our examination shows the PACN to be a convenient guide to the RN.

Anatomical investigation of a new vertical obturator nerve block technique.

BACKGROUND: We evaluated a vertical obturator nerve block (VOB) using a single morphological landmark and no additional distance measurement or obligatory changes of the needle's direction. MATERIALS AND METHOD: A total of 88 cadavers (176 lower limbs), prepared using Thiel's embalming method, were examined. The index finger was placed lateral to the palpable pubic tubercle and the needle inserted laterally to the distal part of the fingernail at the tubercle's level and advanced strictly perpendicular to the table's surface. If bone contact was made, the needle was slightly turned to pass the bone distally. Colored latex (5 ml) was then injected. The injection depth was documented, then followed by dissection and nerve exposition. The real skin-nerve distance and the degree of difficulty in orientation and of palpation were measured. Additionally, the dissemination around the nerve or its branches and the intrapelvic spread were documented. RESULTS: The nerve was colored completely in 93.75%, partially in 1.71%, and not colored in 4.54% of cases. The mean injection depth was 3.9 cm (±0.7 SD) and real nerve depth was 3.8 cm (±0.69 SD). Bone contact necessitating the needle's redirection was found in 20 (11.4%) cases. Easy orientation and palpation of the tubercle was always found. In 40 cases, the latex spread via the obturator canal into the lesser pelvis. CONCLUSION: In this anatomical study, the VOB technique exhibits easy orientation without stimulation or ultrasound guidance. The nerve was located at a constant depth. The injection offered a high percentage of colored nerves.

Conformational properties of a polyglycine chain with secondary and tertiary structures of lysozyme.

Unperturbed dimension mean value of r2(0), dipole moment mean value of mu2, mean squared optical anisotropy mean value of gamma 2 and molar Kerr mean value of mK constant of a polyglycine chain with the secondary and tertiary structures of lysozyme have been calculated and the results compared with polyglycine chains with the same number of repeat units but different conformations including alpha-helix, beta-sheet or random coil. Thus, the influence of secondary and tertiary structures can be investigated. The results obtained show that for mean value of r2 and mean value of gamma 2 this influence is at least of the same order of magnitude as that of the primary structure, and is much greater for mean value of mu 2 and mean value of mK.

Dependence of some conformational properties of polyglycine on composition and sequence of secondary structure.

The values of four conformational properties, unperturbed dimensions 0, dipole moment , mean squared optical anisotropy and molar Kerr constant have been calculated for polyglycine chains of x = 100 repeat units with varying composition of alpha-helix, beta-sheet and random coil conformations. The influence of the conformational sequence on these properties has been investigated by calculating the four above-mentioned properties together with the end-to-end vector for several polyglycine oligomers.

Influence of secondary structure of polyglycine on some conformational properties.

Values of four conformational properties, namely unperturbed dimension [r2]0, dipole moment [mu 2], mean squared optical anisotropy [gamma 2], and molar Kerr constant [mK], have been calculated for polyglycine chains allowing several combinations of the secondary structure with the aim of studying the dependence of these magnitudes on the secondary structure of the chain. Two different approaches to the secondary structure have been used. In the first, chains with all their units in a given conformation (random coil, alpha-helix or beta-sheet) are interrupted at several positions by one unit in a different conformation. In the second, chains with varying composition of two conformations alpha-helix/beta-sheet and beta-sheet/random coil were allowed and the results obtained compared with previous work for alpha-helix/random coil chains.