Trapezius muscle transfer for external shoulder rotation: anatomical study

Abstract

OBJECTIVE: To compare the viability of transferring the lower and transverse trapezius to the greater tuberosity using three different techniques. METHODS: Twelve shoulders from six cadavers were used. The primary outcome was to assess the suture viability of the trapezius muscle transfer to the greater tuberosity in the insertion topography of the infraspinatus, with the arm adducted during internal rotation (hand on the abdomen) and maximum scapular retraction. Three transfers were applied to each shoulder: the lower and transverse trapezius distal insertion (Group 1); lower trapezius alone (Group 2); and lower trapezius insertion and origin (Group 3). Accessory nerve integrity was assessed before and after transfers. RESULTS: Sutures were viable in 42% (5/12) and 58% (7/12) on Groups 1 and 3, respectively, with no statistically significant difference (Fisher's test, p=0.558); Group 3 exhibited frequent neurologic injury (11/12). Group 2 was the least successful; the tendon did not reach the greater tuberosity, and no sutures were viable. CONCLUSION: Groups 1 and 3 exhibited the best nongrafting suture viability to the greater tuberosity; however, Group 3 was associated to frequent spinal accessory nerve injury. Level of Evidence IV, Anatomical Study

Rotator cuff irreparability or failure of repair (re-tear): technical note on middle trapezius tendon transfer for reproduction of supraspinatus function

“….To overcome the latter limitation of LTTT, MTTT to SSP footprint is to exert a force vector almost collinear to that of SSP; so offering a biomechanical rationale for MTTT as a management option of irreparable SSP tear [ 8 , 13 ].…”

“….In spite of this limited release, effective excursion of the released tendon portion can be achieved by wide blunt dissection of its undersurface from underlying SSP; however, this release should not be advanced beyond the medial scapular border to avoid injury of the spinal accessory nerve as the latter courses 1–2 cm medial to that border [ 8 , 13 ].…”

“…Moroder et al showed that in retracted-scapular position; acromial portion of the middle trapezius can be directly transferred to RC footprint without interposition tendon graft; however, this was not feasible in protracted-scapular position; concluding that need for interposition graft remains questionable and should be intraoperatively-considered on dynamic basis to negate excessive tension over the tendon reconstruct. Similarly, in a Newcastle shoulder model of virtual LTTT; Reddy et al demonstrated necessity of interposition allograft to minimize risk of trapezius over-tensioning [ 8 , 13 , 15 ].…”

“…Compared with that of Moroder et al, current description is technically safer; as it doesn’t violate acromio-clavicular joint for maximizing length of the harvested trapezius tendon. Besides, interposed hamstring sheet is to effectively lengthen the transferred tendon of the middle trapezius; thus, lessening sub-periosteal dissection of the trapezius, reducing tension over the tendon reconstruct and minimizing displacement of trapezius neuro-vascular bundle [ 8 , 13 , 15 ].…”

“….For reproduction of SSP function; middle trapezius tendon transfer (MTTT) might offer a number of potential biomechanical (e.g., almost collinear force vector with that of SSP), biological (e.g., abundant blood supply) and technical (e.g., simplified tendon harvest/convenient room of SSP fossa for gliding motion of tendon reconstruct) advantages which in turn are to result in almost re-normalized gleno-humeral (GH) kinematics and satisfactory clinical outcomes especially with regard to restoration of active GH elevation [ 8 , 13 , 14 , 18 ].…”