Shoulder arthrodesis using a vascularized scapular pillar graft: Cadaver study and surgical technique

Abstract

Introduction: Whether secondary to trauma, infection or tumor invasion, a complex reconstruction procedure is required after proximal humerus resection. Among the reconstruction options, there are few published reports of a vascularized scapular pillar graft being used. The goal of our study was to describe the surgical technique for shoulder arthrodesis using a vascularized scapular pillar based on an anatomical study of this graft.

Materials and methods: This anatomical and surgical study involved both shoulders from seven separate cadavers (14 shoulders). Two shoulders were used for trials. Four shoulders were injected with latex to describe the vascularization of the composite scapular pillar graft. Five fresh shoulders were then used to define the optimal orientation of the osteotomy and rotation of the scapular pillar. Each vascularization element was then isolated and measured. The shoulder arthrodesis procedure using a composite scapular pillar graft was performed on three shoulders in order to describe the steps of this procedure.

Results: The angular branch of the thoracodorsal artery was 8.25±1.5 cm long and reached the lateral angle of the scapula 1.6±1.1 cm above its antero-inferior edge. The mean length of the circumflex scapular artery was 5.25±1 cm with 3 cm separating the inferior edge of the glenoid and the end of the artery in question. Optimal graft positioning was achieved with a glenoid osteotomy of the pillar that was horizontal in the frontal plane and angled 20° downward and forward in the sagittal plane. This resulted in the pillar being turned 240° medially (internal rotation).

Discussion: The latex injection study confirmed that the scapular pillar always has two vascularization sources: circumflex scapular artery and angular branch of the thoracodorsal artery. While there are anatomical variations, the scapular pillar shares its vascularization with the latissimus dorsi and teres major muscles. It can be preserved when transferring the graft for reconstruction. Our anatomical description of shoulder arthrodesis using this composite graft allows surgeons to anticipate potential technical and anatomical problems that could be encountered during this complex surgical procedure.

Keywords: Anatomical study; Proximal humerus reconstruction; Scapula; Shoulder arthrodesis.