Hand & Wrist

Tendon Laceration

A tendon laceration is a cut through one or more of the tendons that control movement of the fingers or wrist. Whether from a kitchen knife, broken glass, a saw, or another sharp object, tendon lacerations in the hand are true surgical emergencies that require prompt evaluation. Delayed or inadequate repair leads to permanent loss of finger motion and grip strength. The hand surgeons at Maryland Orthopedic Specialists are experienced in both primary tendon repair and complex reconstructive procedures, and we are available for urgent consultations at our Bethesda and Germantown offices.

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What is tendon laceration?

Tendons are the fibrous cords that connect muscles to bone and transmit the forces needed to bend and straighten the fingers and wrist. Two systems govern finger movement: - Flexor tendons run along the palm side (volar surface) and bend the fingers.

Tendons are the fibrous cords that connect muscles to bone and transmit the forces needed to bend and straighten the fingers and wrist. Two systems govern finger movement:

Flexor tendons run along the palm side (volar surface) and bend the fingers. Each finger has two: the flexor digitorum profundus (FDP), which bends the fingertip, and the flexor digitorum superficialis (FDS), which bends the middle joint.
Extensor tendons run along the back of the hand and fingers (dorsal surface) and straighten them.

Flexor Tendon Zones

The flexor tendons are divided into five anatomic zones. Zone II (from the base of the finger to just below the finger's middle joint) is the most surgically demanding zone, historically called "no man's land." In Zone II, both FDP and FDS tendons travel through a tight fibro-osseous tunnel (the flexor tendon sheath) surrounded by a precise system of pulleys. Repair in this zone requires meticulous technique to restore the tendon's gliding surface and prevent adhesions.

Zone I: FDP only, distal to the FDS insertion; injury results in loss of DIP joint flexion.
Zone II: Both FDP and FDS in the fibro-osseous tunnel; highest risk for adhesion formation.
Zone III: Palm, between carpal tunnel exit and A1 pulley; more forgiving environment.
Zone IV: Within the carpal tunnel; multiple structures at risk.
Zone V: At the wrist and forearm level; typically associated with significant injuries.

Extensor Tendon Zones

Extensor tendons are divided into eight zones (odd numbers over joints, even numbers between joints). Extensor injuries are generally more accessible surgically than flexor injuries but require careful attention to tendon tension, as both excess length and shortening impair function.

Partial vs. Complete Lacerations

A partial laceration (less than ~60% of tendon substance) may not completely abolish motion but still requires careful assessment. Partial cuts weaken the tendon and create a risk of delayed rupture or triggering.

Symptoms — do you recognize these?

Inability to bend a finger at the DIP joint (FDP injury) or PIP joint (FDS injury)
Inability to straighten a finger (extensor tendon injury)
A visible cut on the palm, finger, or back of the hand
Pain, bleeding, and swelling following a laceration
Numbness or altered sensation alongside the finger (associated digital nerve injury)

Call us at (301) 515-0900. Same-day appointments available at our Bethesda and Germantown locations.

How we diagnose it

Diagnosis is primarily clinical:

Examination of active motion: Each tendon is tested in isolation. The FDP is tested by stabilizing the PIP joint and asking the patient to flex the DIP; the FDS is tested by holding all other fingers in extension and asking the patient to flex the injured finger at the PIP.
Wound exploration under tourniquet control: Wounds must be explored surgically to determine the extent of tendon damage, the retraction of tendon ends, and associated injuries to digital nerves, arteries, and pulleys.
X-rays: Obtained to identify associated fractures or foreign bodies (e.g., glass, metal fragments).
Neurovascular examination: Digital Allen's test and two-point discrimination assess arterial and nerve integrity.

The position of the hand at the time of injury is critical: tendons retract proximally when the hand is opened after injury, so the laceration in the skin does not align with the tendon injury location.

Treatment options

Non-Operative

Splinting alone is appropriate only for minor partial lacerations; most tendon lacerations require surgery.

Surgical Repair

Repairing the tendon within 10–14 days of injury gives the best results, and starting a supervised therapy program within days of surgery helps prevent scar tissue from limiting movement. When a significant delay or extensive scarring makes direct repair impossible, a two-stage reconstruction using a tendon graft restores function.

Recovery & rehabilitation

Flexor tendon recovery is one of the most demanding rehabilitation processes in hand surgery:

Immediate post-op: Dorsal protective splint; hand therapy begins within 3–5 days with an early active motion protocol.
0–6 weeks: Progressive active and passive mobilization under therapist supervision; no resistive exercises.
6–8 weeks: Splint weaned; progressive strengthening begins.
3–4 months: Return to most activities.
6–12 months: Final functional plateau. Extensor tendon repairs generally recover more quickly (8–12 weeks for return to activities), though distal injuries may require extended splinting.

Consistent attendance at hand therapy is the single most important predictor of a good outcome after tendon repair.

Frequently Asked Questions

My finger can still bend a little. Does that mean the tendon isn't cut?

Not necessarily. FDS function may be preserved if only the FDP is cut. Partial cuts may also allow some movement. Any wound near a tendon over a finger requires formal evaluation.

How long after injury can a tendon be repaired?

Primary repair is ideal within 10–14 days. Repairs are technically more difficult after 4–6 weeks due to scarring and tendon shortening, often requiring grafting.

Will I have normal finger movement after repair?

Many patients regain excellent function with proper repair and dedicated therapy. Zone II injuries have the most variable outcomes due to the complexity of the sheath and pulley system. Realistic expectations and early therapy engagement are essential.

Can a nerve also be cut at the same time?

Yes. Digital nerves run alongside the flexor tendons and are frequently injured together. Nerve repair is performed at the same time as tendon repair.

How long does recovery take after tendon repair in my hand, and when can I use my hand normally?

Recovery after flexor tendon repair in the hand requires a supervised hand therapy program beginning within days of surgery using a protective splint and a carefully controlled early motion protocol. The repaired tendon is protected from strong gripping for approximately six to eight weeks while it gains enough strength to tolerate loading. Light use of the hand typically resumes at eight to twelve weeks, with full grip strength and unrestricted use expected by four to six months. At MOS, your hand surgeon will coordinate your care with a certified hand therapist to maximize the chance of achieving excellent motion and prevent the tendon from rupturing or scarring down during the critical healing window.

Meet the specialists

Peter G. Fitzgibbons, MD

Hand Surgery · Orthopedic Surgery

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Medically reviewed by Peter G. Fitzgibbons, MD

Last reviewed May 1, 2026