Island flap supplied by the dorsal branch of the ulnar artery

Two cases are reported in which a fasciocutaneous island flap was employed supplied by the ulnaris dorsalis artery after the method proposed by Becker and Gilbert. The original technique has been modified by the authors, and this produces a better venous outflow. The vascular pedicle includes, besides the ascending branch of the artery and the venae comitantes, one of the superficial veins together with its respective subdermal band. A technique is also described that provides an optimal length for the vascular pedicle.     

The lateral root of the ulnar nerve

In 158 brachial plexuses the origin of the fibers of the ulnar nerve-whether only from the medial or also from the lateral fascicle-was investigated. A lateral root was found in 56%. This lateral root may either be accompanied by fibers of the median nerve (type 1) or may run separately (type 2). Where this root crosses the medial root of the median nerve, either a small minority of fibers of the latter nerve may run behind the ulnar fibers (type a), or all median fibers are in front of them (type b). Considering the relation 56:44% between ulnar nerves with and without a lateral root both possibilities have to be considered as normal variations, none as a variety. In analogy to the term 'median loop' the term 'ulnaris loop' is suggested for specimens with a lateral root.     

Biomechanical adaptation of ulnar cross-sectional morphology in brachiating primates

The forelimbs of hylobatids (gibbons and siamang) are distinctive among tetrapods in that they are loaded in overall tension during normal locomotion. While hylobatid ulnae must also encounter bending stresses in the course of their full range of locomotor behavior, their loading regime differs from that of quadrupedal anthropoids in that these bending stresses are distributed evenly along the bone, are not exerted in a preferred plane, and are probably of generally lower magnitude. This study examines the degree to which hylobatid ulnae are adapted to this suspensory loading regime. We obtained cross-sections of ulnae at various increments along the length of the bone using CAT scans. The sample comprises 476 cross-sections representing the ulnae of 25 individuals from five species of comparable body size. We show that in gibbons and siamang, the patterning of ulnar cross-sectional area and resistance to bending in the dorsoventral plane along the ulnar diaphysis differ from that of similarly sized quadrupedal anthropoids in the manner predicted by a suspensory loading regime. We also find the same pattern for the ulnae of Ateles, whose loading regime may be fairly similar to that of hylobatids. However, we find that the cross-sectional shape of the ulnar diaphysis in hylobatids and Ateles does not differ from that of quadrupedal monkeys in the manner predicted by a suspensory loading regime. © 1995 Wiley-Liss, Inc.     

A reverse ulnar hypothenar flap for finger reconstruction

A reverse-flow island flap from the hypothenar eminence of the hand was applied in 11 patients to treat palmar skin defects, amputation injuries, or flexion contractures of the little finger. There were three female and eight male patients, and their ages at the time of surgery averaged 46 years. A 3 x 1.5 to 5 X 2 cm fasciocutaneous flap from the ulnar aspect of the hypothenar eminence, which was located over the abductor digiti minimi muscle, was designed and transferred in a retrograde fashion to cover the skin and soft-tissue defects of the little finger. The flap was based on the ulnar palmar digital artery of the little finger and in three patients was sensated by the dorsal branch of the ulnar nerve or by branches of the ulnar palmar digital nerve of the little finger. Follow-up periods averaged 42 months. The postoperative course was uneventful for all patients, and all of the flaps survived without complications. The donor site was closed primarily in all cases, and no patient complained of significant donor-site problems. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer, as indicated by 5 mm of moving two-point discrimination. A reverse island flap from the hypothenar eminence is easily elevated, contains durable fasciocutaneous structures, and has a good color and texture match to the finger pulp. This flap is a good alternative for reconstruction of palmar skin and soft-tissue defects of the little finger.     

Neurochemistry of the dorsal horn

The dorsal horn region of the spinal cord, particularly the dorsal root entry zone (DREZ), represents the first central integration center for nociceptive afferent impulses. Here, the excitatory neurotransmitters/modulators, products of the primary sensory neurons, are released, the segmental interneuronal influences pertain, and the descending bulbospinal tracts terminate. A vast variety of compounds are thus involved in the processing of nociceptive information in these areas, among which are the 'classical' neurotransmitters and the more recently described neuropeptides. A continued vast interest exists concerning the chemistry of the dorsal horn/DREZ region. The current developments and understanding regarding the pharmacology of this region are presented. Particular emphasis is given to the interactions among the various compounds, the coexistence of some of these within single neuronal populations, the importance of the opiate receptor subtypes, and the actions and localizations of some of the newly discovered neuropeptides.