bubble_chart Overview

Hand tendon injuries are mostly open, with lacerations being the most common, often accompanied by neurovascular injuries or bone and joint injuries. Closed lacerations can also occur. After a tendon rupture, the corresponding joint loses its function. For example, if the flexor digitorum superficialis tendon is ruptured, the proximal interphalangeal joint of the corresponding finger cannot flex; if the flexor digitorum profundus tendon is ruptured, the distal interphalangeal joint cannot flex; if both the flexor digitorum superficialis and profundus tendons are ruptured, both the proximal and distal interphalangeal joints cannot flex. Since the intrinsic hand muscles remain intact, the flexion of the metacarpophalangeal joint is not affected. Ruptures of the extensor tendons at different locations result in the inability to extend the corresponding joints and may lead to deformities.

bubble_chart Treatment Measures

(1) Rupture of the Extensor Tendon Insertion Mostly caused by poking injuries, sudden flexion of the distal interphalangeal joint can avulse the extensor tendon attachment, and local cutting injuries can also sever it. It manifests as a mallet finger deformity, with some patients accompanied by avulsion fractures.

1. Open Wounds After debridement, suture the tendon, position the finger in hyperextension of the distal interphalangeal joint and flexion of the proximal interphalangeal joint to relax the extensor tendon, and fix with gypsum or aluminum splint for 4-6 weeks.

2. Closed Wounds Fix in the above position for 4-6 weeks. If accompanied by a large avulsion fracture, early surgery can be performed using the "pull-out wire method" to fix the fracture fragment, with external gypsum or aluminum splint fixation.

3. Old Injuries The proximal tendon retracts, forming a scar at the rupture site, relaxing the tendon. If the functional impact is minimal, no treatment is needed. If the functional impact is significant, surgical treatment is required, making an S-shaped incision on the dorsal side of the distal interphalangeal joint, flipping the skin flap, and overlapping suture of the muscle membrane. Postoperatively, fix in the above position for 4-6 weeks.

(2) Rupture of the Central Slip of the Extensor Tendon During finger flexion, the dorsal side of the proximal interphalangeal joint protrudes, making it prone to injury, often accompanied by central slip rupture. Normally, the central slip and the lateral slips are on the dorsal side of the finger's long axis. After central slip rupture, the lateral slips can still extend the finger. If the central slip is not repaired, with finger flexion, the lateral slips gradually slide toward the palmar side, and then the lateral slips cannot extend the finger, instead causing flexion of the proximal interphalangeal joint and hyperextension of the distal interphalangeal joint, forming a typical "boutonniere" deformity.

(3) Injuries to the Extensor Tendons on the Dorsum of the Hand, Wrist, and Forearm All should undergo primary suture of the ruptured extensor tendons, with good results. When ruptured at the dorsum of the wrist, the corresponding part of the dorsal transverse ligament and synovial sheath should be incised to place the tendon directly under the skin.