In short. Why early treatment of a divided tendon matters, how flexor and extensor repairs differ, and why rehabilitation decides the result more than the suture technique.
Key points
- A technically perfect tendon repair can still end in a stiff finger.
- Tendon healing is a race between the repair gaining strength and the tendon sticking to its surroundings.
- Modern practice uses a strong core suture with a fine circumferential stitch, then begins controlled movement within days under a therapist’s protocol.
Tendons connect muscle to bone and transmit the force that moves a finger. When a tendon is cut, the finger stops moving — not because the finger itself is injured, but because the cable that pulls it has been divided. A hand with an intact finger and a divided tendon is a hand that cannot grip.
Flexor and extensor injuries
Tendons on the palm side bend the fingers and are called flexors; those on the back straighten them and are called extensors. A cut on the palm side of the wrist or finger usually divides flexors, often more than one, and may also divide the digital nerves and arteries that run beside them. Extensor injuries on the back of the hand are, in general, more forgiving. A clean injury from a blade behaves differently from a crush injury or a rupture where a tendon tears against bone.
Why early treatment matters
Tendons retract when divided, scar quickly, and lose their smooth gliding surface if they are left. The longer the delay, the more the tendon ends retract and adhere, and the harder it becomes to restore smooth movement. Clean cuts are ideally repaired within days, in an operating theatre, with the wound explored so that nerve and artery injuries are not missed.
Therapy decides the result
A technically perfect tendon repair can still end in a stiff finger. Tendon healing is a race between the repair gaining strength and the tendon sticking to its surroundings. Modern practice uses a strong core suture with a fine circumferential stitch, then begins controlled movement within days under a therapist’s protocol. Movement stops adhesions forming, and the protection built around that movement stops the repair pulling apart.
What repair can and cannot achieve
It can restore continuity and, with therapy, restore useful movement. It cannot restore a normal tendon. Repaired tendons are not as strong as uninjured ones for many months, and a repair can rupture if the hand is used forcefully too early, which is a specific and avoidable complication. In some fingers, particularly where both flexor tendons are divided inside the sheath, a staged reconstruction with a tendon graft is needed instead.
Recovery and follow-up
Strict splinting and graded exercise continue for six to twelve weeks, with hand therapy throughout. Strengthening comes later, and full use returns over several months. Final assessment is made at twelve months or longer. Stiffness is the commonest problem, and therapy is what prevents it.
Seek care urgently if
- Movement is suddenly lost after tendon repair, or a pop is felt in the finger.
- The hand becomes pale, cold, blue, or numb, or bleeding will not stop with pressure.
- The wound becomes red, hot, or discharging, or a fever develops.
Frequently asked questions
Why does a cut tendon need repairing quickly?
Tendons retract when divided, scar quickly and lose their smooth gliding surface if left. The longer the delay, the more the ends retract and adhere, and the harder it becomes to restore smooth movement.
What is the biggest risk after tendon repair?
Rupture, which happens when the hand is used forcefully too early. Repaired tendons are not as strong as uninjured ones for many months, which is why splinting and a graded exercise programme are followed strictly.
Does a good tendon repair guarantee a good result?
No. A technically perfect repair can still end in a stiff finger, because healing is a race between the repair gaining strength and the tendon sticking to its surroundings. Therapy is what decides the outcome.
Risks & Limitations
- Incomplete return of sensation or movement. Nerve recovery is slow — roughly a millimetre a day — and some feeling or movement may never come back.
- Stiffness and contracture. A stiff hand is the commonest reason a technically good operation gives a disappointing result.
- Rupture of a tendon repair with forceful use too early in the protected period.
- Infection, which may require antibiotics and further surgery.
- Scarring and scar contracture. Scars are permanent, may stay sensitive or cold-intolerant, and can tether a joint or a web space.
- Growth disturbance in children, which may require later surgery as the hand grows.
- Prolonged hand therapy. Splinting and graded exercise are part of the treatment, not optional aftercare.
- No outcome is guaranteed. Final assessment is made at 12 months or longer, and longer still in growing children.
When to Seek Care
- A hand that becomes pale, cold, blue or numb, or fingers that change colour.
- A wound that becomes red, hot or discharging, or a fever above 38 °C.
- Sudden loss of movement after tendon repair, or a pop felt in the finger.
- Severe pain or swelling in a cast or splint, or a splint that has become too tight.
- Bleeding that does not stop with gentle pressure.
- New or worsening numbness or weakness at any stage after surgery.
References & Further Reading
- American Society for Surgery of the Hand (ASSH) — hand and upper limb condition guidance
- American Society of Plastic Surgeons (ASPS) — reconstructive and hand surgery guidance
- Cochrane Library — systematic reviews in hand surgery and hand therapy
- Chinese Medical Association, Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.