Glenoid notching after reverse shoulder arthroplasty: The influence of different neck-shaft angles.

Background: The implications of notching in reverse shoulder arthroplasty (RSA), and its relation with the rate of complications are still unclear. Our main aim was to retrospectively study the notching incidence in the three most used implants in our practice, considering their different neck-shaft angle (NSA) and determine its relation with implant failure, or other complications.

Methods: We retrospectively reviewed medical and imaging records of 259 patients who underwent RSA in our hospital, including surgery reports, prosthesis designs and techniques. We assessed all radiographs taken during the follow up to evaluate notching incidence, progression and signs of failure.

Results: Notching occurred in 35% cases. The average time to notch development was 19 months. Implants with a lower NSA showed significantly lower incidence of notching when compared to other implants ( < 0.001). In a multivariate analysis, the NSA proved to be an independent predictor for the occurrence of notching in this series.

Discussion: According to our results, higher NSA is an independent predictor of the occurrence of notching. There was significant increase in the notching rate with follow up. In the future, larger case series with longer follow-up are necessary to evaluate the relation between notching and radiological and clinical complications.