Review Question - QID 219880

This 64-year-old male patient presents with glenohumeral osteoarthritis. Patients with glenoid retroversion greater than 15 degrees often necessitate glenoid component augmentation (Answer 2) during total shoulder arthroplasty (TSA).

Glenohumeral arthritis is a commonly encountered entity in clinical practice, often necessitating surgical intervention in the form of TSA. In primary osteoarthritis patients, posterior erosion can occur on the glenoid, leading to asymmetric wear patterns and ultimately dysplastic glenoid bone stock, which most often manifests in excessive glenoid retroversion. Methods to address these deformities are largely dependent on the degree of retroversion. In those with less than 15 degrees, eccentric reaming can be performed to restore the native version, while those greater than 15 degrees often require glenoid augmentation. The 15-degree threshold was established because eccentric reaming greater than this is believed to compromise subchondral bone and risk glenoid vault penetration, ultimately compromising glenoid component fixation. Because of this, glenoid augmentation or bone grafting is recommended, with recent literature suggesting the former leads to reduced complication rates.

Luedke et al. performed a systematic review examining the management and outcomes of 239 patients with Walch B2 glenoid morphology undergoing TSA. Of the 239 patients, 127 underwent asymmetric reaming, 53 received bone grafting, and 34 received augments as management of their glenoid retroversion. While the authors note significant improvements in symptoms regardless of technique, they observed a revision rate of 15.6% for asymmetric reaming, 9.5% for posterior glenoid bone-grafting, and 0% for posteriorly augmented glenoids. The authors conclude glenoid retroversion continues to be a difficult problem to manage and is fraught with complications; however, augmentation may be superior for more severe deformity.

Denard and Walch reviewed the impact of B2 glenoid morphology on shoulder arthroplasty outcomes. The authors noted hemiarthroplasty can be performed in young adults, particularly when including the "ream and run" technique, but recognize results have been mixed. Therefore, the authors recommend TSA for those with mild deformity but acknowledge severe deformity (posterior humeral head subluxation > 80%, retroversion > 27 degrees) portend unacceptably high rates of complications and believe reverse TSA can be a viable alternative.

Figure A represents an AP view of the left shoulder demonstrating glenohumeral osteoarthritis with a maintained acromioclavicular interval. Illustration A demonstrates the Walch Classification.

Incorrect Answers:
Answer 1: retroversion of this magnitude can be remedied through eccentric reaming alone
Answers 3 and 4: these deformities can be addressed when performing the humeral head cut and positioning the stem
Answer 5: the presence of this characteristic suggests an incompetent rotator cuff, which necessitates reverse TSA.