La prothèse d'épaule en 2010: Prothèse anatomique ou prothèse inversée? Indications et contre-indications

Abstract

Three different types of shoulder arthoplasty are currently used. Anatomical total shoulder arthroplasty, composed of two implants, which replicate normal anatomy: a humeral metallic stem ended with a hemisphere, which articulates with a concave polyethylene glenoid implant. Indications are arthropathies with functional rotator cuff: osteoarthritis, inflammatory arthropathies, aseptic osteonecrosis (grade 4 and 5 of Ficat-Arlet classification) and minor post-traumatic malunions. In those indications and without complication, pain relief is achieved in more than 90% of cases and active elevation reach in average 130°. Contra-indications are non-functional rotator cuff, insufficiency of glenoid bone stock and permanent glenohumeral instability. Reversed total shoulder arthroplasty, composed of a concave humeral implant, which articulates with a hemispherical glenoid implant. It is semi-constrained and indications are mainly cuff tear arthropathy, major post-traumatic malunions and the majority of prosthetic revisions. Results are in average excellent for pain relief, good for active elevation, more variable on internal rotation and active external rotation. Reverse arthroplasty offers solutions on previously unsolved problems. Some indications are not yet validated, as inflammatory arthropathies with deficient cuff and comminuted osteoporotic fractures in elderly patients. Contra-indication is non-functional deltoid. Excepted for particular cases, follow-up is currently too short to recommend reverse arthroplasty before 70 years. Hemiarthroplasty, which is the humeral part of the total anatomical prosthesis, articulates directly with glenoid cartilage or glenoid bone. It is indicated if glenoid side is intact as in aseptic osteonecrosis stage 2 or 3 in Ficat-Arlet classification or post-traumatic osteonecrosis. Humeral head fracture, very comminuted or with an important risk of necrosis, may be treated with a special hemiarthroplasty characterized by a large window, which helps for fixation and healing of tuberosities around the stem: this major goal is not always achieved, explaining very variable results in this indication. Hemiarthroplasty may be also a solution if conversely, glenoid bone stock is not sufficient to accept an implant, as in end stages of rheumatoid arthritis or end stage of cuff tear arthropathy: the goal is here only for pain relief. © 2010 Société française de rhumatologie.