These authors point out that glenoid component loosening is a primary cause of failure of anatomical total shoulder arthroplasty (aTSA) and is commonly associated with glenoid bone loss.
They evaluated the outcome and survival following revision to a reverse total shoulder arthroplasty (RSA) for the treatment of loosening of a polyethylene cemented glenoid component in the setting of failed aTSA in 127 shoulders.
The mean age at the time of surgery was 70 years (range, 41 to 93 years). In all cases, the humeral component was revised and a standard glenoid baseplate was utilized. Bone graft was used at the discretion of the treating surgeon. The mean duration of follow-up was 35 months (range, 24 to 84 months).
Overall, revision to RSA resulted in significant improvements in terms of pain and motion, however on average patients did not achieve over 90 degrees of elevation.
Sixteen shoulders (13%) underwent re-revision surgery for the treatment of baseplate loosening.
Radiographic baseplate loosening was present in 6 additional shoulders (overall rate of baseplate loosening, 17%).
Intraoperative fracture or fragmentation of the greater tuberosity occurred in 30 shoulders (24%).
Other reoperations included resection for deep infection (3 shoulders), arthroscopic biopsies for unexplained persistent pain (2 shoulders), humeral tray exchange for dislocation (2 shoulders), revision for humeral loosening (1 shoulder), irrigation and debridement for hematoma (1 shoulder), and internal fixation of periprosthetic fracture (1 shoulder) (overall reoperation rate, 20%).
Among shoulders with surviving implants at the time of the most recent follow-up, pain was rated as none or mild in 83 shoulders (65.4%) and the average active elevation and external rotation were 132 and 38, respectively.
The authors conclude that loosening of glenoid components following aTSA remains a challenging problem. While revision to RSA is a viable treatment option, great care must be taken to ensure primary stability of the reverse baseplate. As a result, they have become more cautious when considering revision to RSA in shoulders with severe glenoid bone loss and consider arthroscopic glenoid removal or revision to an appropriately sized hemiarthroplasty as alternative options for the treatment of this challenging clinical problem in patients with severe glenoid bone loss.
Another recent article, The effect of glenoid bone loss and rotator cuff status in failed anatomic shoulder arthroplasty after revision to reverse shoulder arthroplasty also evaluated outcomes and the risk of re-revision in patients with a failed anatomic total shoulder arthroplasty (aTSA) that were revised to a reverse shoulder arthroplasty (RSA) based on rotator cuff deficiency and glenoid bone loss. They found that the overall re-revision rate was 11.4%, with a mean time to re-revision of 22 months (range, 0-89 months). The odds ratio was 1.786 for subsequent revision in patients with glenoid loosening compared with those without loose glenoids on preoperative radiographs.
Comment: We have found that many patients with glenoid component failure can be safely and effectively managed by glenoid component removal, smoothing of the residual glenoid bone and inserting a humeral head component with a large diameter of curvature. Here are three example cases.
So, as emphasized by these authors, a patient with a failed glenoid aTSA glenoid component should not reflexively be treated by revision to a reverse. In selected individuals, safer alternatives may exist.
