Loosening and revision rates after total shoulder arthroplasty: a systematic review of cemented all-polyethylene glenoid and design of the modern metal-backed glenoid

Abstract

Background: Modern designs of metal-backed glenoids (MBG) have been devised to overcome flaws such as loosening and a high failure rate.This review aimed to compare rates of complications and revision surgeries between the modern metal-backed glenoid (MBG) and the cemented polyethylene glenoid (PEG).Methods: Literature search was carried out using PubMed, Cochrane Library, EMBASE, and Google Scholar using MeSH terms and natural keywords. A total of 1186 articles were screened. We descriptively analyzed numerical data between the groups and statistically analyzed the categorical data, such as the presence of radiolucent line, loosening, and revision surgery (failure). Articles were divided into 3 groups based on follow-up duration: short-term < 36 months, midterm 36-72 months, and long-term > 72 months.Results: This study included 35 articles (3769 shoulders); 25 on cemented PEG and ten on the modern MBG. Mean age was 66.4 (21-93) and 66.5 years (31-88). The mean duration of follow-up was 73.1 (12-211) and 56.1 months (24-100). Overall, the rate of the radiolucent line was 354/1302 (27%) and 47/282 (17%), the loosening rate was 465/3185 (15 %) and 22/449 (5%), and the failure rate was 189/3316 (6%) and 11/457 (2%), for PEG and MBG, respectively. The results of short-and mid-term FU studies showed lower rates of radiolucency and loosening in the cemented PEG group, but there was no significant difference in failure rate (P=0.754 and 0.829, respectively). In long-term FU, MBG was better in terms of loosening (P <0.001) and failure rates (P = 0.006). Conclusions: The modern MBG component, especially TM glenoid, seems to be a promising alternative to cemented PEGs, based on subgroup revision rates according to the follow-up duration and overall results of ROM and clinical scores. All polyethylene glenoids tend to increase loosening and failure over time. The modern MBG seems to have no difference in failure, at least in the short-and mid-term compared to the cemented PEG. More long-term follow-up studies on modern MBG should be ultimately conducted. 42 30 7 8 N 1 0