Flexor and Extensor Tendon Lacerations
What Happens If You Cut a Tendon in Your Hand?
A cut, laceration, or forceful injury that prevents a finger from bending or straightening normally may involve a flexor or extensor tendon — the tendons responsible for finger movement — and typically requires prompt evaluation, since tendon injuries generally need surgical repair and don't heal well on their own.
Flexor vs. extensor
Flexor tendons run along the palm side of the fingers and bend them; extensor tendons run along the back of the hand and fingers and straighten them. Injury to either can come from a cut, a crush injury, or in some cases a forceful jamming injury (as with a "jersey finger" flexor injury in sports).
Diagnosis and Treatment:
Diagnosis is largely clinical — testing whether the finger can actively bend or straighten at each joint reveals which tendon(s) are involved. Repair generally requires surgery to reconnect the tendon ends, followed by a carefully structured hand therapy protocol, since tendons need controlled early motion to heal without becoming stiff or re-rupturing.
Frequently Asked Questions:
Can a tendon injury heal without surgery?
Most complete tendon lacerations need surgical repair — without it, the finger typically won't regain normal bending or straightening.
Why is hand therapy so important after tendon repair?
A structured, carefully progressed motion protocol prevents the repaired tendon from becoming stiff or scarred while protecting it from re-rupture during early healing.