Operative Treatment of Complex Hand Injuries Using Microsurgery and External Fixator

Introduction: Reliable initial treatment with a view toward 2-stage reconstruction and a treatment plan centered on postoperative rehabilitation are important to improving the function of replanted fingers and reconstructed hand after severe trauma.

Methodology and Material: 1) Thirty one cases including incomplete amputation, severe crush injury, burn at the level of the forearm and the hand underwent reconstruction by free or pedicled tissue transfer. Twenty two cases underwent tissue transfer secondary to replacement of severe scarring which had caused adhesion of tendon and nerve in the traumatized tissue. Nine cases underwent tissue transfer in the emergency operation to avoid the occurrence of severe scar formation which is believed to cause loss of tendon and nerve function in the future.

2) Thirteen replanted fingers who wore a hinge type external fixator for the purpose of traction of a proximal interphalangeal (PIP) or metacarpophalangeal (MP) joint and ROM exercise. The structure of the modified Ilizarov minifixator ™ for joint ROM (Global hinge fixator ™) was unique. We can use this fixator for solid bone fixation at the primary operation and change its structure 2 to 4 weeks later to make it suitable for ROM exercises without taking off the wires.

The patients ranged in age from 15 to 72 years old (mean: 48 years).　Postoperative follow-up periods after secondary reconstruction ranged from 4 to 61 months.

Results: Functional outcome of major group was estimated by Chen’s criteria. The final outcome was as follows, 5 cases in grade Ⅳ, 8 cases in grade Ⅲ, 9 cases in grade Ⅱ and 9 cases in grade Ⅰ. The average TAM of the replanted finger was 56.5%. Functional assessment by the Japanese Society for the Surgery of the Hand yielded a score of 65 points (Good).

Conclusions: To reconstruct the function of the traumatized forearm and hand, it is necessary to prevent the occurrence of severe adhesion around the tendon and nerve by replacing the scar tissue using flaps. To acquire better joint function, it is logical to start using an adjustable external fixator that allows ROM exercise while exerting traction on the finger joint before bone union.