Anterior deltoid insertion distance to various bony landmarks before and after humeral head lateralization

Abstract

Aim: Moment arm of anterior part of deltoid muscle is increased as working principle of reverse shoulder arthroplasty and anterior part of deltoid muscle insertion could be damaged during proximal humerus surgery. The purpose of the present study was to report distances from various bony landmarks to anterior, superior, medial insertion points of deltoid before and after implantation 5mm thick glenoid implant. Patients and Methods: 12 shoulders of formalin fixed adult cadavers were used at the present study. The distances from greater tubercle to deltoid insertion, anterior-lateral corner of acromion to deltoid insertion, coracoid tip to deltoid insertion, upper pole of glenoid to deltoid insertion, and humeral length (greater tubercle to lateral epicondyle) were measured using digital caliper and measurement tape before and after implantation of 5mm thick pegged glenoid trial (Bigliani/Flatow Total shoulder arthroplasty, Zimmer, Warsaw, IN). Results: At tape measurement, glenoid to deltoid insertion distance was higher at post implant group at right shoulders (p:0.04). When all shoulders were compared, coracoid to deltoid insertion distance was higher at implanted group (p:0.04). Conclusion: Deltoid insertion lateralization could be detected from the bony landmarks around the glenoid especially the coracoid tip.

Keywords

• deltoid
• insertion
• coracoid
• acromion
• great tubercle
• deltoid
• insersiyo
• korakoid
• akromiyon
• tüberkulum majus