Twin-peg and single-peg unicompartmental knee arthroplasty designs show comparable clinical outcomes and radiographic results: A systematic review.

Purpose: This systematic review compares single-peg and twin-peg unicompartmental knee arthroplasty (UKA) implant designs with respect to radiographic findings, clinical outcomes and implant longevity. Methods: A search strategy was applied to four databases, including PubMed, Scopus, Embase, and Web of Science. Inclusion criteria focused on studies of the twin-peg and single-peg designs in the UKA. Two reviewers independently performed screening, data extraction, and quality assessment. Study characteristics, patient demographics, clinical outcomes, revision rate and radiographic differences were extracted. We utilized the Risk of Bias (RoB) 2 tool and Risk of Bias in Non-Randomized Studies of Intervention to assess the RoB in included studies. Results: Seven studies were included in the final review. Results varied in the case of radiographic scores, clinical outcomes and patient-reported outcome measures (PROMs). Some studies demonstrated advantages for twin-peg designs in component positioning, but others identified no significant differences. PROMs indicated improvements with both implants, but there was no evidence to clearly prefer one design over the other. Twin-peg designs showed slightly lower revision rates in some studies, but evidence remains inconclusive regarding overall superiority. Revision causes included pain, osteoarthritis (OA), instability, infection and aseptic loosening. Conclusions: The study found that twin-peg designs may have superior outcomes, but overall results did not support either design, conclusively. Level of Evidence: Level III, systematic review.