A convertible shoulder system: is it useful in total shoulder arthroplasty revisions?

The frequency of total shoulder arthroplasty (TSA) implantation is constantly increasing. This leads to revisions because of stem or glenoid component loosening, infection, instability or glenoid subsidence. Significant rotator cuff lesions and/or bone loss necessitate reverse shoulder arthroplasty (RSA) with bone reconstruction, which is a demanding procedure. Our hypothesis is that a platform system (versatile humeral stem with metal back glenoid component) makes revision surgery less demanding and less time consuming, and helps reduce the risks of complication. The purpose of this study is to analyse our revision experience with such a system to support our hypothesis. We present 29 revision cases of a convertible platform shoulder system: five hemi arthroplasties (HA), eight TSA with cemented glenoid (TSACG) and 16 TSA with metal backed glenoid component (TSAMB). Three TSACG were switched to TSAMB, and 26 other arthroplasties were switched to RSA. The pre-operative Constant score was 27 (range, 0-38). Our revision incidence was 5.4 % (29 revisions out of 537 shoulder arthroplasties over five years). At revision, Constant score was 60 (range, 42-85). The humeral stem (versatile with TSA and RSA) was kept in three out of four cases. Most of the time it was changed because of too high a position, making it impossible to reduce the RSA. Nevertheless, 12 PTAMB were switched in 12 RSA without any metal backed revisions. A platform shoulder system allows much easier revisions.