Minimum 5-year outcomes of pegged versus keeled all-polyethylene glenoids

Glenoid loosening remains one of the most common concerns at mid- to long-term follow-up after total shoulder arthroplasty (TSA). Pegged and keeled designs have been compared at short-term follow-up, but few studies have compared outcomes at mid-term follow-up. Our purpose was to compare minimum 5-year outcomes of pegged and keeled cemented, all-polyethylene glenoids in TSA. The hypothesis was that no difference in functional outcomes or loosening would be found between the 2 components.

We performed a multicenter retrospective study of TSAs with either a pegged or keeled cemented glenoid. At a minimum of 5 years postoperatively, functional outcomes and radiographic loosening were compared.

Forty-seven TSAs were available for follow-up, including 20 pegged and 27 keeled components, at a mean of 79 months (range, 60-114 months) postoperatively. Overall, functional outcomes improved in both groups from preoperatively to postoperatively, and no difference was found between the 2 groups. Radiographic glenoid loosening (score ≥ 3) was observed in 9 of 27 keeled glenoids (33.3%) compared with 5 of 20 pegged glenoids (25%) (P = .54). Loosening was associated with lower postoperative forward flexion (P = .026), lower American Shoulder and Elbow Surgeons scores (P = .030), and higher visual analog scale pain scores (P = .007).

Radiographic glenoid loosening of a cemented, all-polyethylene component was associated with decreased functional outcomes at minimum 5-year follow-up of TSAs. However, this study showed no difference in loosening rates between keeled and pegged components.