What is it?
Extensor tendons are responsible for extension are located on the dorsal part of the hand. They extend fingers and the wrist. They may be compared to a string, this is connected with the muscle/motor located on the forearm on one side and a finger or the wrist on the other. The tendon transfers force from the motor to the effector.
The extensor tendons become flatter and thinner as they get nearer to the fingers. They form a very complicated finger extending system additionally supported by small muscles located inside the hand.
The most frequent cause of an extensor tendons damages are injury, e.g. incised or lacerated wounds. Their location, directly under the skin makes damaging them easy. A blow in the finger or a punch with the hand very often results in breaking the tendon. Very often, such braking is accompanied by bone damage.
Certain diseases predispose to spontaneous damage/ breaking of the tendons, e.g. RA, osteoarthritis, gout.
The symptoms are usually easy to recognize, because a patient notices reduced or lack of possibility to extend the finger. Finger drop can occur immediately after the injury, but sometimes, a few days after the injury, the patient finds that active extension of the finger is impossible.
Examination and diagnosing the disease
Diagnosing of the disease is based on the presented symptoms and on collecting a complete medical history describing the mechanism of the injury (a blow, crush, an incised or lacerated wound) and the time when it happened by the doctor. In case of a spontaneous breaking of the tendon, it is important to find the reason why it occurred: (RA, osteoarthritis, overburdening?
The choice of the method of treatment depends on the type of injury and time that elapsed from the moment of the event. Incised wounds resulting in breaking continuity of the tendon require suturing of the tendon. The sooner the surgery is performed, the better post-operative effect can be achieved. In case of extensive injury of the finger extensor tendons it may become impossible to suture the ends of the broken tendons – then it is necessary to apply extra-anatomical connecting of the tendons in order to reconstruct extension of the finger / wrist. Such conduct is often recommended in secondary/ delayed post-injury reconstructions of extensor tendons.
After the surgery, immobilization of the finger or hand is usually recommended (spatula, thermoplastic mass, plaster, orthosis) and then rehabilitation. In some cases, simultaneous immobilization may be recommended together with rehabilitation. Selection of the treatment proceedings depends on the decision of your doctor. Fusion of the sutured tendons is very often connected with fusion of the nearby tissues – formation of adhesions, which may limit or even block finger movement. In such cases, performance of other surgeries is necessary.
The most common injuries of extensor tendons
- Mallet finger – breaking of the distal section of the of the extensor tendon resulting in finger drop of last finger phalanx. Initially, the treatment is conservative – special immobilization of the finger for at least 6 weeks. In case of open wounds and when tendon breaking is accompanied by detachment of a bone fragment of the distal phalanx of the finger, it is recommended to perform the necessary surgery immediately after the injury.
- The so-called boutonnière deformity – breaking of the central band of the extensor apparatus of the finger resulting in bending the finger in the proximal inter-phalanx joint and the compensation hypertrophy in the distal inter-phalanx joint. Initially, the treatment is conservative – specialist immobilization of the finger with simultaneous exercising the distal inter-phalanx joint. In case of lack of positive result of the conservative treatment, your surgeon may suggest a surgery.
- Cutting or rupture of the extensor tendons - result in lack of extension of a finger, fingers or hand, depending on an extension of the injury. The best effects are obtained after immediate restoration-suturing of the continuity of the tendon. The treating surgeon decides whether a Patient needs immobilization and when the Patient can start his or her rehabilitation.