Functional Assessment in Hand with Flexor and Extensor Tendon Injuries

Abstract

Integrity of flexor and extensor tendons is a major prerequisite for dexterous hand function. While flexor tendons on the volar side of the forearm and hand flex the fingers for grasping, extensor tendons on the dorsum straighten the wrist and the fingers to release or reach the objects. Flexor tendons are usually injured by lacerations. Extensor tendons travel close to the skin on the dorsal surface of the hand. They are susceptible to crush injuries, as well as lacerations, burns, bites, or blunt trauma. Both tendons are divided into zones according to the anatomical characteristics of the structures they overlie or travel with. Flexor tendons are classified into five zones, while extensor tendons are evaluated and treated in seven zones. These accompanying structures which enable perfect hand function in healthy people may cause severe adhesions that may hinder tendon gliding after an injury. The primary aims of rehabilitation after tendon injury are to gain maximum tendon gliding, to ensure effective joint motion, and to restore hand function. It is also very important to prevent tendon rupture, contracture, and excessive scarring. In order to achieve these goals, various early active and passive mobilization methods for the first four postoperative weeks have been described. While the major advantage of early active mobilization protocols is to provide controlled active mobilization of the repaired tendon, it necessitates maximum cooperation of the patient and the rehabilitation team. The patient must understand that the optimum result depends on both home-based and also supervised exercises repeated daily for a few times. He should also be cautioned against the risk of tendon rupture during the first weeks of the repair. Strengthening exercises and splinting to prevent contractures are implemented after the eighth week. While the therapy focuses on maintaining the motion and strength of the injured hand, rehabilitation physician and the team members should direct the patient to use the unaffected body regions to decrease his disability due to trauma or disease. Disability may result both from physical limitations and from distortion of social and occupational roles. Although each has some limitations, hand function and disability are measured by validated and reliable methods and scales.