Tendon and Nerve

Tendon Transfer

Pre-requites for a successful tendon transfer

• Stability of proximal joints
• Prior correction of any fixed deformity
• At least grade 4/5 power
• Direct line of pull
• Firm point of fixation - preferably bone

Joint mobility is maintained pre-operatively by physiotherapy. There can be no fixed contractures. Postoperatively the joint is splinted for at least six weeks.

The best way of attaching tendon to bone is to drill a tunnel through the bone and loop the tendon back onto itself and then suture the tendon to itself.

Suture of tendons

Severed tendons are best sutured primarily. In some situations such as Zone 2 (under the flexor pulleys in the palm) special suture techniques such as the Kessler suture allow a less bulky suture line.

Nerve Repair

Classification of nerve damage

1. Neurotmesis (complete division) Usually seen in open wounds e.g. knife wound. The nerve is completely severed.
2. Axonotmesis (incomplete division) Only the axoms are divided. Usually in traction and closed injuries. Clinically it in indistinguishable from axomomesis, but complete recovery is likely
3. Neurapraxia (physiological interruption) The axoms are intact and the only injury is degradation of the axon sheaths. Motor loss is usually seen and sensory loss is less common.

Nerve Suture

Nerve Suture. Fascicles are matched and epineuruim sutured   with 6/0 or finer material

Timing of repair

• Immediate exploration and suture of open injuries
• Closed nerve injuries can be treated conservatively (i.e. splints and physiotherapy) and observed for signs of recovery. Repair is undertaken at 6 weeks to a few months later if necessary.

Signs of nerve recovery

• Return of sensory or motor function
• Progressive Tinnel sign  ( point of percussion tenderness over nerve course) migration distally.
• Speed of growth about 6mm per week. The distance to the target organ is thus critical. The higher the lesion, the worse the prognosis.