This biomechanical study uses a validated epoxy shoulder model implanted with a reverse prosthesis to determine whether latissimus dorsi transfer (LDT) can restore external rotation when RSA is used for shoulder pseudoparesis, and which of three insertion sites on the humerus provides the greatest mechanical advantage.
When performing RSA for pseudoparesis with deficient external rotation, this study supports adding latissimus dorsi transfer with reinsertion on the posterior greater tuberosity — adjacent to the teres minor footprint — to maximize the external rotation moment arm; routing the tendon around rather than over the tuberosity is the geometric key to the mechanical advantage.
This biomechanical study uses a validated epoxy shoulder model implanted with a reverse prosthesis to determine whether latissimus dorsi transfer (LDT) can restore external rotation when RSA is used for shoulder pseudoparesis, and which of three insertion sites on the humerus provides the greatest mechanical advantage.
When performing RSA for pseudoparesis with deficient external rotation, this study supports adding latissimus dorsi transfer with reinsertion on the posterior greater tuberosity — adjacent to the teres minor footprint — to maximize the external rotation moment arm; routing the tendon around rather than over the tuberosity is the geometric key to the mechanical advantage.