Tendon Transfer Options for Trapezius Paralysis: A Biomechanical Study.

Abstract

The purpose of this study was to evaluate the biomechanical effectiveness regarding scapulothoracic (ST) upward rotation of two different tendon transfer procedures involving the levator scapulae, rhomboid major, and rhomboid minor to restore the function of the paralyzed trapezius. Six fresh frozen hemithoraces were mounted on a custom-built apparatus. A three-dimensional electromagnetic tracking system was used to record ST upward/downward rotation of the (1) normal trapezius, levator scapulae, rhomboid minor, and rhomboid major; (2) Eden-Lange (EL) transferl and (3) a modified EL transfer (triple transfer). The normal trapezius was found to be an upward rotator of the scapula and led to a mean ST rotation angle of 26.98°. Similarly, the modified triple transfer led to an upward rotation of the scapula, with a mean ST rotation angle of 22.23°, whereas the EL led to an initial downward rotation of the scapula to -6.69°, with a mean scapulothoracic displacement angle of 1.13°. The upward rotation of the scapula from the modified transfer mimicked the function of the normal trapezius better than did the traditional EL transfer. Level V, biomechanical study.