Conversion of Failed Anatomic Total Shoulder Replacement With Severe Glenoid Bone Defect to Humeral Hemiarthroplasty

Abstract

IntroductionGlenoid component loosening is a common cause of late failure after anatomic total shoulder arthroplasty (aTSA) and revision can be challenging due to glenoid bone loss. Revision to reverse shoulder arthroplasty (RSA) requiring glenoid bone graft is associated with relatively high failure rates. Revision to humeral hemiarthroplasty (HHA) is an alternative. The purpose of this study was to evaluate the outcomes of revision of failed aTSA, with severe glenoid bone loss and intact rotator cuff to HHA. MethodsThis was a retrospective study of 18 patients (12 males) with failed aTSA, intact rotator cuff, and severe glenoid bone loss who were revised to HHA at a mean age of 68.9 ± 9.2 years and 9.0 ± 4.1 years after index aTSA. Mean follow-up was 7.6 ± 5.7 years. Glenoid defects were uncontained in 6 (33%). Glenoid bone grafting was performed in 11 (61%). A larger humeral head was used in 15 (83%) cases. Outcomes were assessed with the Simple Shoulder Test (SST), VAS pain, VAS quality of life (QoL), and shoulder range of motion. Plain radiographs were analyzed. ResultsThere were significant improvements in SST (p=0.005) and VAS pain (p<0.001). Mean active forward elevation improved from 106 ± 36° to 120° ± 21° (p=0.062). MCID for SST was met in 7 (39%) and VAS pain in 11 (61%). At final follow-up, 11 patients (61%) were satisfied with their current symptoms, two (11%) rated their satisfaction as neutral, and five (28%) were dissatisfied. There was progressive humeral medialization in 8 that was not significantly associated with the use of glenoid bone grafting (p=0.912). Greater humeral medialization was strongly correlated with less improvement in SST (ρ= 0.68) and VAS QoL (ρ=-0.64). Seven patients had ≥ 2 positive intraoperative cultures, all Cutebacterium acnes. Three patients (17%) underwent subsequent revision to treat persistent pain and dysfunction; 1 to HHA, 2 to RSA. ConclusionRevision of failed aTSA with severe glenoid bone loss and functional rotator cuff to HHA can provide improved pain and patient reported outcome with low complication and re-revision rates, and should be considered in selected cases.