Tendon injuries of the hand

Abstract

Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients. Most injuries are open injuries to the flexor or extensor tendons, but less frequent injuries, e.g., damage to the functional system tendon sheath and pulley or dull avulsions, also need to be considered. After clinical examination, ultrasound and magnetic resonance imaging have proved to be important diagnostic tools. Tendon injuries mostly require surgical repair, dull avulsions of the distal phalanges extensor tendon can receive conservative therapy. Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair. In the postoperative course of flexor tendon injuries, the principle of early passive movement is important to trigger an "intrinsic" tendon healing to guarantee a good outcome. Many substances were evaluated to see if they improved tendon healing; however, little evidence was found. Nevertheless, hyaluronic acid may improve intrinsic tendon healing.

Keywords: Extensor tendon; Flexor tendon; Pulley injury; Tendon lesion; Tendon sheath.

Figure 1

The pulley system of the long fingers (modified according to Schmidt and Lanz[8]).

Figure 2

Complete pulley system during a stress test in the biomechanical laboratory. (Figure with permission of Schöffl V, MD, PhD, Institute of Anatomy, University of Erlangen-Nuremberg, Germany[9]).

Figure 3

A2-pulley rupture during a stress test in the biomechanical laboratory. Note the increased distance between the flexor tendons and the bone. The A3-pulley is unharmed. (Figure with permission of Schöffl V, MD, PhD, Institute of Anatomy, University of Erlangen-Nuremberg, Germany[9]).

Figure 4

Closed flexor tendon rupture of the flexor digitorum profundus at the level of the middle phalanx (rock climber)[9].

Figure 5

Lumbrical tendon rupture (note the edema and the dislocated lumbrical tendon from the flexor tendon).

Figure 6

Degenerative flexor tendon rupture in a long term rock climber with chronic tendinosis.

Figure 7

Degenerative flexor tendon rupture in a long term rock climber with chronic tendinosis. The histology showed a mucoid degeneration with numerous blood vessel proliferations and a siderosis as a sign of an older bleed[9].

Figure 8

Ruptured A3 pulley (the tendon sheath with chronic inflammation is already removed).

Figure 9

Algorithm for pulley injuries[3]. MRI: Magnetic resonance imaging.