Extensor tendon injuries: acute management and secondary reconstruction.
OBJECTIVE
After reviewing the article, the participant should be able to: (1) Describe the anatomy of the extensor tendons at the level of the forearm, wrist, hand, and fingers. (2) Recognize variations in the anatomy. (3) Master the hand examination and define the relevant findings in acute injuries of the extensor tendon(s). (4) Delineate the techniques for extensor repair in both acute and secondary (delayed) management.


CONCLUSIONS
Extension of the fingers is an intricate process that reflects the combined action of two independent systems. The interossei and lumbricals constitute the intrinsic musculature of the hand. These muscles innervated by the median and ulnar nerves extend the proximal interphalangeal and distal interphalangeal joints and flex the metacarpophalangeal joints. The extrinsic extensors are a group of muscles innervated by the radial nerve, originating proximal to the forearm. The extrinsic digital extensor muscles include the extensor digitorum communis, extensor indicis proprius, and extensor digiti quinti. The digital extensors function primarily to extend the metacarpophalangeal joints, but also extend the proximal interphalangeal and distal interphalangeal joints. Normal extensor physiology reflects a delicate balance between these two unique extensor systems. In the injured hand, a functioning intrinsic system may potentially compensate for an extrinsic deficit. An understanding of the relevant anatomy and an appreciation for the complex interplay involved in extensor physiology is necessary to recognize and manage these injuries.
Hanz
Kevin R
KR
Dallas, Texas From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, and the Parkland Health and Hospital System.
Saint-Cyr
Michel
M
Semmler
Maynard J
MJ
Rohrich
Rod J
RJ
D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology; D010808:Physical Examination; D019651:Plastic Surgery Procedures; D013708:Tendon Injuries / Q000175:diagnosis / Q000534:rehabilitation / Q000601:surgery / Q000628:therapy*; D013710:Tendons / Q000033:anatomy & histology*; D034941:Upper Extremity / Q000033:anatomy & histology*