[Free functional gracilis muscle transplantation for reconstruction of active elbow flexion in posttraumatic brachial plexus lesions].

OBJECTIVE

Reconstruction of powerful active elbow flexion. Reconstruction of missing muscle unit by neurovascular pedicled functional muscle transplantation.

INDICATIONS

Treatment of last choice for --secondary reconstruction of active elbow flexion in case of complete lesion of the brachial plexus or musculocutaneous nerve (M0 muscle function = replacement indication), partial but incomplete lesion of the brachial plexus or musculocutaneous nerve (M1-(3) muscle function = augmentation indication); --replacement of the elbow flexor muscles in case of primary muscle loss (tumor, trauma).

CONTRAINDICATIONS

Concomitant lesions of the axillary artery. No adequate donor nerve. Relative: no sensibility at all at the forearm and hand.

SURGICAL TECHNIQUE

Free functional biarticular myocutaneous transplantation of gracilis muscle. A myocutaneous gracilis flap is raised at the thigh. At the upper arm the flap is fixed proximally to the coracoid process or the lateral clavicle. The distal insertion is sutured to the distal biceps tendon. Vascular anastomoses are carried out in end-to-side fashion with the brachial artery and vein. Nerval coaptation is done in end-to-end technique using the muculocutaneous nerve.

POSTOPERATIVE MANAGEMENT

Complete immobilization for 6 weeks. Dorsal upper arm splint until sufficient muscle power (M(4)). Progressive increase of active range of motion for another 6 weeks. Continuation of physiotherapy for 12-18 months. Postoperative standardized compression therapy, combined with scar therapy (silicone sheet).

RESULTS

Functionally useful results can be expected in 60-75% of patients, especially if there is some residual function (M1 or M2) left ("augmentation indication"). Early free functional muscle transplantation shows best results in patients with direct muscle defect, because all vascular and neuronal structures are still available, and no secondary changes such as fibrosis or joint stiffness are present yet. There are inconsistent results for patients with neurologic insufficiency (i.e., total brachial plexus palsy) or mixed neuromuscular insufficiency, such as compartment syndrome. Especially in complete brachial plexus lesion, free functional muscle transfer is often the only treatment option. Provided there is a good patient selection, satisfactory results can be achieved for elbow flexion. Whether a higher number of axons, as provided by the contralateral C7 transfer, will lead to better results is the topic of an ongoing study.