Glenoid perforation with pegged components during total shoulder arthroplasty

Abstract

A subset of patients undergoing primary total shoulder arthroplasty (TSA) have a medialized joint line secondary to glenoid wear. In some cases, the central pegs or peripheral pegs of a peg design glenoid component may violate the medial cortex of the glenoid vault. It is unknown whether this leads to early failure. The objectives of this study were to determine (1) whether glenoid components with uncontained pegs would be associated with a high rate of failure and (2) whether peg perforation would be associated with inferior clinical outcomes. The authors performed a case-control retrospective review comparing 25 TSAs in which one or multiple pegs perforated the medial glenoid vault (uncontained group) with 25 TSAs without peg perforation (contained group). Implant survival was calculated with revision for glenoid component loosening as the primary outcome variable. Clinical outcomes were determined using American Shoulder and Elbow Surgeons (ASES) and Penn Shoulder Scores. Average follow-up was more than 5 years. No patient in either group had symptomatic glenoid loosening. Two (8%) patients in the uncontained group required revision for rotator cuff tears. Penn and ASES scores were significantly lower in the uncontained group (Penn, P=.002; ASES, P=.004). Pain and satisfaction subscores were similar between the groups, but function subscores were significantly lower in the uncontained group (Penn, P=.002; ASES, P=.005). Uncontained pegs of an anchor peg glenoid component are not associated with early glenoid loosening. Similar pain relief is obtained when compared with contained glenoid components, but shoulder function is significantly lower in patients with uncontained pegs.