Kinematics of the wrist with a new dynamic external fixation device

The kinematic properties of a new dynamic external fixator device for treatment of distal radial fractures are described. Using a combination of data obtained from computed tomography scans and high-speed video images, a three-dimensional reconstruction of carpal motion was made. To describe carpal motion, the radiolunate, capitolunate, and scapholunate angles were measured during flexion and extension and during radioulnar deviation. During these types of motion, the device changed normal carpal kinematics to a limited extent although the differences in kinematic pattern with and without the device were small. The results for flexion and extension correspond with data from previously published studies with other dynamic external fixators. However, because the new device (Flexafix) allows flexion and extension and radioulnar deviation, in contrast to other dynamic external fixation devices, with its use normal carpal kinematics can be approached more closely.

Innervation of the metacarpophalangeal and interphalangeal joints: a microanatomic and histologic study of the nerve endings

Six pairs of fresh human cadaver hands were dissected under the surgical microscope at x28 to x32 and selectively silver stained. In addition, 18 proximal interphalangeal and metacarpophalangeal joints of fresh cadaver hands were processed with protein gene product 9.5 for measurement and analysis of nerve endings in those joints. The results demonstrated that the proximal interphalangeal joints are innervated by 2 palmar articular nerves (mean diameter, 0.21-0.53 mm). Each metacarpophalangeal joint of the second through fifth fingers is predominantly supplied by 1 palmar articular nerve (mean diameter, 0.41-0.59 mm), which comes from the deep branches of the ulnar nerve, as well as by 2 dorsal articular nerves (mean diameter, 0.11-0.24 mm). The metacarpophalangeal joint of the thumb also had 2 dorsal articular nerves (mean diameter, 0.18-0.24 mm) and 2 palmar joint nerves (mean diameter, 0.29-0.31 mm). The mean densities of the type IV free nerve endings and the mean numbers of the encapsulated endings in the palmar capsules were consistently much greater than in the dorsal or lateral capsules. The majority of encapsulated endings were pacinian corpuscles. The anatomic and histologic information may help the surgeon avoid damaging these small joint nerves during operative procedures and to reconstruct or de-innervate them if necessary. (J Hand Surg 2000; 25A:128-133.

Pediatric throwing injuries about the elbow

Pediatric elbow injuries that result from repetitive throwing-type activities are common. These injuries differ from those seen in adults, because of anatomic differences. The purpose of this paper is twofold: first, to review the anatomy of the elbow and the mechanics of the throwing motion about the elbow, and second, to discuss the diagnosis, treatment, rehabilitation, and prevention of pediatric throwing injuries of the elbow.

Malignant eccrine poroma of the hand: a case report

Carcinoma of sweat glands is a very rare neoplasm that is difficult to diagnose clinically and histologically. This report presents a case of malignant eccrine poroma of the hand which is a distinct histologic subtype of sweat gland carcinoma with a high local recurrence rate. A distal radial artery based forearm flap was used to provide soft tissue coverage.

Anatomy of the palmar cutaneous branch of the median nerve: clinical significance

A detailed anatomic, histologic, and immunohistochemical study of the palmar cutaneous branch of the median nerve (PCBMN) and its distal arborization was undertaken on 12 fresh human cadaveric hands. Small unmyelinated fibers terminated in the superficial loose connective tissue of the transverse carpal ligament. There were no nerve fibers detected in the deep, dense collagen aspect of the ligament. Based on these findings, during open carpal tunnel release, the skin incision should be placed along the axis of the ring finger to avoid injury to the superficial branches of the PCBMN. When open release is used, the very small terminal branches in the loose tissue of the ligament will be transected; this may in part be responsible for postoperative soft tissue pain. For endoscopic releases, some risk for transection of the main trunk of the PCBMN at the proximal incision exists. Repeated passes of the endoscopic knife should be avoided in an attempt to limit damage to the small fibers in the superficial aspect of the ligament.