Freek Hollman, Mohamad Jomaa, Richard Page, Marine Launay Jashint Maharaj, Kenneth Cutbush, Ashish Gupta
This study is conducted, by using data from the AOANJRR, to study the differences in survival rate for different types of glenoid components in all age groups.
Since the introduction of the total shoulder arthroplasty numerous designs have been proposed regarding the glenoid components. Currently, mainly three types of glenoids of are used in Australia (modular metal backed, all-polyethylene and non-modular metal backed). From previous literature, metal backed implants report lower implant survival as compared to all-polyethylene.
Data from the AOANJRR 2021 was used. In total 7850 patients were included in the database. Three types of glenoid components were compared regarding the revision rate (modular metal backed (n=2121), all-polyethylene (n=4817) and non-modular metal backed (n=912)). The highest revision rate is described for total shoulder arthroplasty amongst patients between 65-74 years (42%). Kaplan-Meier survivorship analysis was performed with revision as the endpoint.
At 10 years of follow-up the general revision rate was 8% (n=591). The cumulative revision rate at ten years for each type individually was: modular metal backed (21.3%), non-modular metal backed (8.5%) and all-polyethylene (6.9%). Additionally, modular metal backed glenoids showed a significantly increased risk for revision as compared to all polyethylene glenoids (HR = 3.34 (2.8-2.98; p < 0.001)) as well as compared to the non-modular metal backed glenoids (HR = 2.24 (1.7-2.96; p < 0.001)).
In conclusion, the AOANJRR from 2021 modular metal backed glenoids showed inferior survival rate as compared to all-polyethylene and non-modular metal backed glenoids. Long term results showed comparable results for all-polyethylene and non-modular metal backed glenoids. Therefore, caution is advised for the use of modular metal backed glenoids in total shoulder arthroplasty amongst patients with osteoarthritis