gms | German Medical Science

Objectives/Interrogation: Functional muscle transfers (FMT) are an option for the management of the paralytic shoulder in brachial plexus lesions that are not candidates for nerve transfers. FMT can be associated with other muscle or nerve transfers in the upper limb to improve the overall function of the upper extremity. Given that in different biomechanical studies the theoretical advantage of the lower trapezius muscle has been demonstrated with respect to the latissimus dorsi as a donor, the objective of this work is to know the surgical anatomy of the dynamic transfer of the ipsilateral and contralateral lower trapezius, and to identify advantages and disadvantages of These two techniques.

Methods: Descriptive study, dissection in cadaveres

Results and Conclusions: A descriptive anatomical study was performed on 20 cadaveric specimens with the transfer of the lower trapezius to the contralateral shoulder (10 specimens) and ipsilateral (10 specimens). The contralateral transfer is indicated when there is paralysis of the ipsilateral trapezius muscle in the paralyzed shoulder or when the function or power of the ipsilateral trapezius it's not enough to be transfer, in the other hand the ipsilateral transfer does not compromise the healthy upper limb of the patient. It was found that in the ipsilateral FMT the spinal accesory nerve should always be visualized and protected during the procedure; as well as performing augmentation with allograft of the Achilles tendon to reach the necessary length when performing posterior or posterosuperior tenodesis to the rotator cuff, this is not necessary in the contralateral technique, since with the extension towards the lumbar fascia that is performed in the dissection as described in the art, sufficient length is achieved to perform the tenodesis. Both techniques allow transfer at the posterior (infraspinatus) or posterosuperior (between supraspinatus and infraspinatus) level of the shoulder. During the dissections, infraspinatus and supraspinatus tendons were always found to perform tenodesis, however in vivo, given the atrophy that the rotator cuff may have, we recommend having anchoring sutures at hand to reinsert the donor tendon directly to the humeral head in case of be necessary. It becomes very important to achieve an adequate tension and tenodesis effect, the position of the shoulder in external rotation and abduction.