Faculty Bibliography

Initial treatment of most compressive neuropathies at the elbow is nonoperative, consisting of rest, avoidance of elbow flexion, and, when necessary, temporary immobilization of the elbow and wrist. If symptoms persist, particularly when accompanied by muscle weakness, surgery is usually indicated. Operative procedures include decompression without transposition of the nerve (in situ or by means of medial epicondylectomy) and decompression with transposition of the nerve carried out in a subcutaneous, intramuscular, or submuscular fashion. The indications, advantages, disadvantages, and surgical technique of each operative procedure are discussed

In the past several years, the role of MR imaging in diagnosing pathologic conditions of the elbow has dramatically increased. Aside from imaging soft-tissue tumors, it can accurately visualize partial and complete tears of tendons and ligaments, as well as displacement of epiphyseal fractures in children. Its role in identifying loose bodies, particularly when they are nonosseous, and areas of osteochondritis dissecans has also increased. The use of MR imaging for diagnosing neuropathies, particularly when electrodiagnostic studies are negative, offers exciting possibilities as additional technical improvements are developed

We performed an in vitro study using canine flexor tendons to compare the tensile properties of a suture technique for flexor tendon repair with the standard modified Kessler technique. The technique employs a central wire loop that connects the two transverse limbs of the modified Kessler suture. Both techniques were studied with and without a Lembert epitendinous stitch. The technique combined with an epitendinous suture provided the strongest resistance to gap formation, and its load at gap initiation was 100% greater than the load in tendons repaired with the modified Kessler and an epitendinous suture. Because of its increased resistance to gap formation, this suture technique may provide a safer margin for controlled early active motion after flexor tendon repair.

An arteriovenous (AV) shunt as a method of restoring venous drainage during replantation was examined by use of the rabbit ear model. The results were compared to ears replanted using one vein (1:1) or two veins (2:1) for venous drainage. The success rate for AV shunt replantations was found similar to that of replantations with a 1:1 ratio, but lower than that of ears with a 2:1 ratio. Postoperatively, ears replanted using an AV shunt or a 1:1 ratio revealed more swelling and lower tissue oxygenation than ears with a 2:1 ratio. After 10-14 days, all ears that survived were similar in appearance, regardless of method of replantation. Microscopic venules crossing the replanted interface appeared at seven days following surgery in all groups. The authors conclude that the AV shunt method offers an alternative to venous anastomosis when vein-to-vein reconstruction cannot be established.

Tomography and magnetic resonance imaging (MRI) are important imaging techniques in the diagnosis and management of a wide variety of wrist disorders. They have been useful for evaluating fractures, tumors, arthritic conditions and avascular necrosis involving the carpal bones as well as injuries affecting the radiocarpal and intercarpal ligaments and the triangular fibrocartilage complex. The indications and clinical applications of each imaging technique will be discussed.

Tomography, which permits a far more accurate visualization of lesions than conventional radiographs, is conducted via several different methods, depending on the specific movement of the x-ray tube. Linear tomography is the simplest method but produces images that appear streaked. Zonotomography, which uses an elliptical or figure-8 movement of the x-ray tube, creates a uniform blurring of structures and a much clearer resolution of the plane of focus. Even sharper images are produced by multidirectional trispiral tomography, which is described as well as its application to specific anatomic areas of the wrist. The normal anatomy and a variety of problems of the wrist as visualized with magnetic resonance imaging are also described.

A new 'bloodless' technique (Ilizarov) was used to correct 36 limb deformities in 29 children. There were six leg length discrepancies, five achondroplasias, four deformed feet, five joint contractures, one rotational deformity of tibia, and in three the apparatus was used as an external fixator after corrective osteotomy. Lengthening was accomplished in 15 of the 16 procedures (93%). Average increase in femur length was 10 cm (32%), in tibial length 7.5 cm (30%), in humerus 11 cm (40%). Bony union was achieved in two out of five pseudoarthroses. Four deformed feet were fully corrected. Joint contractures were corrected in four out of five. The complication rate is as high as in other methods but with the Ilizarov apparatus, longer segments of bone were lengthened and more complex deformities were treated. Complications lessened as experience was gained

A fresh cadaver study of the effects of a variety of scaphoid stabilizations on wrist motions is reported. Scaphoid-trapezium-trapezoid stabilizations with the scaphoid in its normal anatomic position and the same stabilizations with the scaphoid in malposition, either vertical or horizontal in relation to the radius, were compared. Scaphoid-capitate stabilizations with the scaphoid in its normal position were also studied. With the scaphoid vertical, a scaphoid-trapezium-trapezoid stabilization resulted in greater loss of wrist flexion and ulnar deviation whereas, with the scaphoid horizontal, wrist extension and radial deviation were more severely affected than when the scaphoid was stabilized in its normal position. With the scaphoid in its anatomic position, both scaphoid-trapezium-trapezoid and scaphoid-capitate stabilizations resulted in similar patterns of wrist motion.

Human immunodeficiency virus type 1 (HIV-1) infection elicits neutralizing antibodies directed against two discrete regions of the gp120 exterior envelope glycoprotein: the third variable (V3) loop and the CD4 binding region. Monoclonal antibodies directed against these two regions demonstrated additive or, in some cases, weakly synergistic neutralization of HIV-1 infection. Cooperativity in virus neutralization was also observed for some gp120 mutants that, in the absence of anti-V3 loop antibodies, were relatively resistant to neutralization by antibodies directed against the CD4 binding region. Although the binding of some anti-V3 region monoclonal antibodies increased the recognition of the multimeric envelope glycoproteins by anti-CD4 binding antibodies, this enhanced binding was not predictive of the degree of cooperativity observed in virus neutralization. These results suggest that elicitation of both types of neutralizing antibodies should increase the efficacy of vaccine preparations