Abstract
Purpose: Surgical prosthetic treatment of excentred degeneration of the shoulder joint has long been limited to simple humeral prostheses. Inverted total shoulder arthroplasty (ITSA) using the Grammont system appears to provide real improvement. What is the comparative outcome? Does the Grammont prosthesis give constant results? Is the simple humeral prosthesis still indicated for selected cases? In order to respond to these questions, we reviewed 84 patients who had undergone surgery between 1986 and 2000 for implantation of 52 simple humeral prostheses (mean follow-up 7.1 years) and 32 ITSA (mean follow-up 4.3 years).
Material and methods: Between 1986 and 1995, all patients with excentred degeneration of the shoulder joint were treated with a simple humeral prosthesis (36 cases). Between 1995 and 2000, either ITSA or simple humeral prosthesis (16 cases) was used. For the ITSA, indications were limited to excentred degeneration in patients aged over 70 years with a painful pseudoparalytic shoulder or contraindication for a simple prosthesis (alteration of the acromiocorocoid vault or the subscapular area). Simple prostheses were used either when an ITSA could not be implanted (patient too young, overly deteriorated glenoid, deltoid insufficiency) or when there was a preferential indication (excentred degeneration in young patients < 65 years, preservation of active motion, Favard type 1 or 2 glenoid…).
Results: For the simple humeral prosthesis series (1986–1995): the Constant score improved from 16.4 preoperatively to 489.6 postoperatively; radiographically there were one humeral loosening, three superior migrations, and three glenoid degenerations; three revision procedures were required. For the ITSA: the Constant score improved from 14.2 preoperatively to 61.6 postoperatively; radiographically there was one humeral loosening; 32% glenoid alterations in Nérot grades 3 and 4; one revision procedure was required. For the later simple humeral protheses (1995–2000): the Constant score improved from 18.2 preoperatively to 56.4 postoperatively (60.2 excluding cases with a simple prosthesis due to contraindication of an ITSA); radiologically there were one superior migration and two glenoid deteriorations.
Discussion: For a given indication, the results with the ITSA were better than with the simple prosthesis (p < 0.001). However, excluding salvage procedures where the ITSA could not be used, simple prostheses inserted for precise indications provided results nearly equivalent to the ITSA (p < 0.05) with less uncertainty concerning the future. For us, the inverted total shoulder prosthesis and the simple humeral prosthesis share indications for surgical repair of excentred degeneration of the shoulder joint.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
