You Cut Your Hand and Now a Finger Will Not Move Normally: Could It Be a Tendon Injury?

A small cut on the hand can hide a much more significant injury underneath the skin.

This is particularly important when the wound crosses an area containing one of the tendons responsible for moving the fingers.

Dr Daniel Durand’s practice treats ligament, tendon and nerve injuries as part of its hand and wrist surgery services, and the existing blog already introduces tendon injuries as an important cause of impaired hand function.

One of the clearest warning signs is simple: after an injury, a finger suddenly does not bend or straighten the way it did before.

Tendons are the mechanical connection between muscle and finger movement

The muscles that move many of the finger joints are located partly in the forearm.

Long tendons transmit the force generated by those muscles to the fingers.

Flexor tendons allow the fingers to bend. Extensor tendons contribute to straightening them.

If a tendon is significantly damaged or completely divided, that mechanical connection can be disrupted. The resulting loss of movement may be immediate.

Why the skin wound can be misleading

A sharp object can pass through a relatively small opening in the skin while damaging deeper structures.

Depending on the location and depth of the injury, tendons, nerves, blood vessels or combinations of these structures may be involved.

This is why the external appearance of a cut does not necessarily indicate the seriousness of what occurred underneath.

A wound that looks modest but is followed by an inability to move a finger normally deserves appropriate assessment.

What does a flexor tendon injury look like?

Flexor tendon injuries affect the structures that bend the fingers.

After a significant injury, one finger may rest differently from the others or fail to bend normally when the person attempts to make a fist.

Partial tendon injuries can be more subtle. Movement may still be possible but painful or abnormal.

Because several tendons and joints contribute to normal finger flexion, identifying the exact structure involved requires more than simply asking whether the finger moves at all.

Extensor injuries can present differently

The extensor mechanism is located along the back of the hand and fingers and is responsible for straightening the digits.

Damage at different levels can produce different patterns of weakness or deformity.

Mallet finger, for example, involves disruption of the extensor mechanism near the fingertip and can cause the end of the finger to droop. It is one of the conditions already discussed in Dr Durand’s patient education material.

Other extensor tendon injuries occur closer to the hand or wrist and can affect movement differently.

Numbness after a cut deserves attention too

Loss of motion is not the only warning sign.

If a cut is followed by numbness on one side of a finger or another clearly defined area, a digital nerve may also have been injured.

Tendon and nerve injuries can occur together because these structures travel close to one another within the hand.

A patient may therefore have both a mechanical problem with finger movement and a sensory problem after the same injury.

Why timing can matter

Hand injuries can become more complicated as swelling, scar tissue and tissue changes develop.

That does not mean every hand cut requires surgery. Many superficial injuries do not involve important deeper structures.

The concern is a wound associated with new loss of movement, abnormal finger position, persistent numbness or another significant functional change.

Those findings warrant timely medical assessment rather than waiting several weeks to see whether normal function spontaneously returns.

Returning function is the priority

The hand is a tightly organized anatomical system. Tendons must glide through specific pathways, nerves must transmit sensation and motor signals, and joints must remain mobile.

Repairing an injured structure is therefore only one part of recovery. Protecting the repair while eventually restoring controlled movement can also be important.

The rehabilitation requirements depend on the structure injured and the type of treatment performed.

Tendon and nerve injury assessment in Montreal

Dr Daniel Durand’s practice includes treatment of complex nerve injuries as well as repair of ligaments, tendons and nerves. Clinic locations are listed in Montreal, Laval and Châteauguay, with patients also seen from elsewhere in Quebec and Canada.