Functional assessment of ray transfer for central digital loss

Nineteen patients who had ray transposition for central digital loss were evaluated retrospectively with regard to postoperative function and appearance. Pinch and grip recoveries were better in patients with small-to-ring finger transfers than in those with index-to-long finger transfers. Total average pinch recovery measured 83.3% of the nonoperated side. Total grip recovery was 80.2% of the nonoperated side. Average ranges of motion for all transferred digits were 77.6 degrees (metacarpophalangeal joint), 87.6 degrees (proximal interphalangeal joint), and 80.8 degrees (distal interphalangeal joint). Overall results judged by a five-component assessment scale were excellent.     

Effect of intravenous glucagon on the survival of rats after acute occlusive mesenteric ischemia

The purpose of this study was to determine the optimal timing of intravenous glucagon infusion for the treatment of acute occlusive mesenteric ischemia. The superior mesenteric artery (SMA) was occluded for 85 min in 106 Sprague-Dawley anesthetized rats. The animals were divided into 12 treatment groups according to the timing of glucagon and saline administration, and survival was measured to 48 hr. Without treatment, all rats died within 24 hr. Intravenous saline (10 ml/kg/hr) for 2 hr did not significantly improve 48-hr survival (17-33%). Glucagon (1.6 micrograms/kg/min iv) plus saline (10 mg/kg/hr iv) for 2 hr after SMA occlusion significantly improved survival from 33% (saline control) to 83% (P less than 0.02). The same treatment begun 1 hr before SMA release (during ischemia) did not significantly improve survival (33% at 48 hr). Glucagon infusion during occlusive mesenteric ischemia was detrimental when added to effective postischemia treatment, reducing survival from 83 to 33% (P less than 0.02). Adequate saline infusion was required for glucagon efficacy after ischemia, as shown by an intermediate 48-hr survival of 50% when only maintenance saline (1.5 ml/kg/hr) was given. These data suggest that glucagon therapy should be delayed until after operative release of an acute SMA occlusion and should be accompanied by vigorous volume expansion.     

Nonoperative management of adult splenic injury due to blunt trauma: a warning

An analysis of 11 patients with splenic injury initially receiving nonoperative treatment revealed that 73 percent subsequently required surgery for delayed hemorrhage. The influence of age and the anatomic differences between the adult's spleen and child's spleen may account for the increased incidence of delayed bleeding seen in this series. Which patients might avoid surgical intervention cannot be predicted with certainty from the mechanism of injury or the lack of early physical signs and symptoms. The corresponding medical problems that often exist with the older patient may make nonoperative management, with the inherent risk of hypotension and large transfusion requirements, inappropriate. Although not advocating immediate splenectomy, we encourage early operative intervention with splenorrhaphy. Although improved diagnostic techniques will uncover a greater incidence of splenic injury, the inability to identify the nonoperative patient remains a clinical dilemma. The true role of nonoperative management of splenic injuries in the adult and the criteria for selection need to be further defined with larger prospective series. Although this approach may be useful for some patients, its application cannot be universal, and one must be willing to accept the consequences of delayed hemorrhage.     

The effect of devascularization on the regeneration of lacerated peripheral nerves: an experimental study.

The functional, biochemical, and histological changes in a severed median nerve, 9 months after epineurial repair, were studied in 14 monkeys. In seven the mesoneurium had been stripped 5 cm proximal and 5 cm distal to the site of repair, and in seven the nerve had been stripped only over a 0.5 cm area, just enough to allow repair. In the first group the mean muscular strength in the abductor pollicis brevis was 197 gm, as compared to 257 gm in the second group. The amount of collagen in the perineurium was 57 microgram/mg, as compared to 43 microgram/mg, and the incidence of the h-l-h-nl cross-link was 16% to 21%, as compared to 9% to 11%. If the regeneration of the lacerated nerve was compromised by the deposition of collagen resulting from mobilization of the distal segment, as suggested by the decrease in the strength of the abductor pollicis brevis muscle, then any mobilization of a nerve necessary to obtain a sutured junction with minimum tension should be limited to the proximal segment.     

The mechanism of the intrinsic-minus finger: a biomechanical study

To demonstrate in the cadaver model that the sequence of extension of the flexed metacarpophalangeal and proximal interphalangeal joints of the intrinsic-minus finger can be explained on the basis of moment ratios about these joints, the engineering concept of free body analysis was applied. Intrinsic-minus fingers, i.e., fingers of a cadaver in which all forces exerted by the intrinsic muscles were removed, were observed to hyperextend maximally at the metacarpophalangeal joint before extension of the proximal interphalangeal joint began. Mathematical calculation of moments provides an explanation of this sequence. This study confirmed that, when an equilibrium of forces at the hyperextended metacarpophalangeal joint is reached, the proximal interphalangeal joint is incompletely extended. These forces include: (1) the proximal pull of the extensor tendon; (2) the distal loading of the extensor tendon by the flexor tendons; (3) the force preventing spanning of the laminae.     

Opposition of the thumb: an anatomic and biomechanical study of tendon transfers

Tendon transfers for opposition of the thumb were anatomically and biomechanically studied to help determine the optimal criteria for selecting the best motor unit for a transfer. Forearm and hand muscle volume, mean fiber length, and cross-sectional area were measured in eight fresh specimens of the upper extremity to determine which muscles best replace lost thenar muscle strength. In a separate group of 18 specimens, the effective moment arms for abduction and flexion of the first metacarpal were calculated in vitro and from biplanar radiographic techniques to determine the effect of eight different opposition transfers on thumb abduction, rotation, and strength. Results of these studies demonstrate that the transfers of flexor digitorum superficialis (FDS) of the long finger and extensor carpi ulnaris best replaced lost thenar muscle strength and provided maximal abduction and near full thumb rotation. The transfers of the extensor carpi radialis longus and the FDS of the ring finger replaced 60% and 40% of required thenar muscle strength, respectively. The palmaris longus was the least effective transfer, having good abduction but weak flexion and opposition. Motion, balance, and strength of tendon transfers must be considered for effective thumb opposition.     

Carpenter's nails, phonograph needles, piano wires, and safety pins: the history of operative fixation of metacarpal and phalangeal fractures

This century has witnessed advances in basic sciences that have led to and resulted from advances in operative fixation of fractures. In addition to the sweeping changes in medicine and surgery, the development of corrosion-resistant alloys underpins all current concepts of fracture surgery. Most of the techniques were originally borrowed from work on large bones and most of the materials came from workshops or sewing boxes. Today, as improved understanding of bone healing and appropriate application of mechanical principles to skeletal injuries have become indispensable for appreciating the relative value of these techniques, operative fixation of hand fractures has emerged as a science in its own right.     

Preiser's disease: a case report

Preiser's disease, or avascular necrosis of the scaphoid, is an exceedingly rare although debilitating pathologic process. A case of progressive avascular necrosis of the carpal scaphoid is presented together with a review of the possible etiology of this rare syndrome. Histologic evaluations of resected specimens have demonstrated a localized sequestrum of necrotic bone, leading to the belief that disruption of blood supply is a major predisposing factor. The diagnosis of Preiser's disease or avascular necrosis of the carpal scaphoid should be exclusively reserved to those cases that demonstrate a progressive clinical and radiographic sequence of osteosclerosis and subsequent fragmentation of the scaphoid.