Whether a physician is working in a...

Whether a physician is working in a rural clinic or an urban academic center or is attending a high drill football game, acute injuries of the hand and wrist will be battleed Patients may not appreciate the severity of these injuries and are as likely to at hand in a clinic as in the necessity department. Timely diagnosis and treatment of upper extremity injuries are of paramount importance. Failure to diagnose, manage, and rehabilitate upper extremity injuries has the potential to deduction in permanent disability. (1)

Part single of this two-part article reviews an anatomic-based examination of the hand and wrist, allowing the physician to quickly evaluate a patient in a nonemergent setting. Part sum of two units (2) focuses on the emergent evaluation of hand and wrist injuries.

Anatomy

Many injuries of the hand and wrist are obvious, nevertheless subtle injuries can be missed without a systematic primary and secondary examination. There are eight carpal bone in the wrist, five metacarpals, and 14 nonsesamoid bone that comprise the phalanges. These 27 bone act dynamically to allow oppositional grip. (3) The proximal file of carpal bones includes the scaphoid (i.e., carpal navicular bone) lunate, triquetrum, and pisiform, which are closely approximated to the distal radius (Figure 1) The triangular fibrocartilage involved an articular disk located between the proximal uproar of carpals and the ulna, integrals the concave surface on which the carpals determine (Figure 2). The distal rank of carpals includes the hamate, capitate, trapezium, and trapezoid, which are closely approximated to the metacarpals. The scaphoid links the pair rows of carpals.

[FIGURES 1-2 OMITTED]

Each digit has sum of two units neurovascular bundles near the palmar aspect of the finger--one located radially and the other ulnarly. The neurovascular put into bundles includes the digital artery, vein, and hardihood (4)

Twelve extensor tendons of the wrist are arranged in six compartments along the dorsum of the wrist. There are multiple slips of the abductor pollicis longus and brace slips of the extensor digiti quinti. The extensors originate in the lateral and dorsal forearm, inserting upon the dorsal aspect of the hand. Twelve flexor tendons of the wrist originate in the medial part of the forearm and insert onward the palmar aspect of the hand and wrist. (5)

Each phalanx has a superficial flexor tendon that inserts at the base of the middle phalanx and a profundus flexor tendon that inserts at the base of the distal phalanx. Consequently injuries of the flexor tendons are more complicated to evaluate and repair than injuries of the extensor tendons.

The extrinsic extensor tendon attaches to the base of the dorsum of the middle phalanx, and bands from the intrinsic hand muscles attach to the distal phalanx. The tendons are cohereed by fibers that form a concealment over the proximal interphalangeal (IP) joint (6) (Figure 3)

[FIGURE 3 OMITTED]

In general, the radial energize accounts for wrist and finger extension, the ulnar endurance provides power grip, the median force allows for fine control of the pincer grip, and the median and ulnar firmnesss supply sensation to the palmar surface. However, to plainly place the hand in a functioning position, the entire upper extremity must be involved. The ulnar endurance enters the hand alongside the ulnar artery in consequence of Guyon's canal, located between the pisiform and the snare of the hamate and shrouded by the pisohamate ligament (Figure 4) The ulnar manhood supplies the intrinsic muscles of the hand as well as the extrinsic muscles for flexion of the fourth and fifth fingers to provide power grip. The ulnar manhood also innervates the adductor pollicis and first dorsal interosseous muscles, which allow pinch. The median steadiness passes into the hand via the carpal subterranean passage of the volar aspect of the wrist. The median steadiness supplies the thenar compartment, providing opposition and circumduction for fine hinder The radial nerve extends the fingers to enhance grasp with the ulnar nerve

[FIGURE 4 OMITTED]

Examination

An efficient way for evaluating the hand is to begin with a primary examine then perform a secondary scan Summaries of each examination are given in Tables 1 and 2

PRIMARY EXAMINATION

The primary contemplate includes evaluation of passive and active range of motion of the fingers and wrist while noting the resting position of the hand. Manipulation is not always necessary; to a great degree can be noted about the hand and fingers with simple observation.

A patient's inability to assume the "safe hand" position (Figure 5) may insinuate a tendon or nerve disruption. (7) If the hand is immobilized in the safe hand position, extension contractures of the metacarpophalangeal (MCP) joint and flexion contractures of the IP joints can be avoided. In normal anatomic position, the thumb is slightly abducted, the MCP joint is at 45 to 70 orders and each of the IP joints is slightly flex at 10 standings Physicians should be alerted to the possibility of tendon disruption if any of the fingers are not maintained in the position (8) (Figure 6) As the hand is clos fingers should point toward the base of the scaphoid (Figure 7)