Augmented vs. standard glenoid baseplate use in reverse total shoulder arthroplasty: a systematic review

Glenoid bone loss can be a challenging problem to address surgically in patients with glenohumeral joint arthritis and concomitant end-stage rotator cuff deficiency. Reverse total shoulder arthroplasty (rTSA) has emerged as a treatment to restore function in this patient population and has demonstrated good clinical outcomes. Addressing bone loss is essential to prevent complication such as glenoid baseplate loosening, scapular notching, and instability. Metal augmentation of glenoid baseplates has shown good clinical and functional outcomes with low complication rates. This systematic review analyzes the outcomes of patients undergoing rTSA with augmented baseplates vs. those treated with a standard glenoid baseplate. Pain, range of motion, patient reported outcomes scores, complication, and revision rates were assessed.

Four online literature databases (PubMed, MEDLINE, ScienceDirect, Scopus) were searched from database inception to July 1, 2024, for comparative studies evaluating outcomes between augmented and standard rTSA. Functional and clinical outcomes along with complication and revision rates were collected across studies. Frequency weighted means were used to synthesize data where appropriate.

Five manuscripts met final criteria for inclusion encompassing 2,331patients with a mean age of 71.3 years and mean follow-up time of 38.8 months. When compared to the standard baseplate group or those treated with bone graft augmentation, the metal augmentation group had comparable improvement in frequency weight means in forward elevation, abduction, and external rotation. Similarly, frequency weighted means of improvement were comprable in the augmented group with regards to American Shoulder and Elbow Surgeons, Simple Shoulder Test, and Constant scores. In studies directly comparing augmented to nonaugmented rTSA, there was a total of 167 (7.5%) reported complications: 132 (7.8%) in the standard and 35 (6.7%) in the augmented cohorts.

This systematic review demonstrates similar functional and clinical outcomes with the use of augmented glenoid baseplates to address glenoid bone loss in rTSA when compared to standard baseplates. Complications were comparable in the augmented baseplate group, with no difference in revision rates. These findings illustrate that augmented baseplates not only address bony defects but can provide good clinical and functional outcomes without the risk of increased complication in rTSA.