HEMI ARTHROPLASTY FOR 4 PART FRACTURE: HOW TO DO BETTER WITH A DEDICATED STEM AND TECHNIQUE: ANATOMICAL AND PRELIMINARY CLINICAL PROSPECTIVE MULTICENTRE STUDY

Introduction:Tuberosity healing is strongly correlated with functional results in all series of three- and four-part fractures of the proximal humerus treated by hemiarthroplasty. We formed a working group to improve position of the implant and fixation of the tuberosities on an implant specifically intended for traumatology.Material and Methods:An anatomic study on 11 cadavers and a prospective multicentre clinical study of 32 cases were performed to validate extrapolable original solutions at the patient scale: placement of the stem at a height indicated in relation to the insertion of the clavicular bundle of the pectoralis major, locking of the stem, placement (based on bone quality) of a variable volume metaphyseal frame (offset modular system® OMS®), avoiding medialisation of the tuberosities, and fixation of the tuberosities using strong looped sutures, brightly coloured so that they can be located more easily. Evaluation by Dash score and Constant score was correlated with positioning of the tuber...