Abstract
PURPOSE: The aim of this systematic review is to analyze and provide an overview of the indications, contraindications and the clinical outcomes to bi-unicondylar knee arthroplasty (Bi-UKA). METHODS: A comprehensive search was conducted to identify original studies written in English reporting indication criteria or clinical outcomes on Bi-UKA) performed simultaneously or at two different stages. Studies reporting patellofemoral implants with medial or lateral implants, ex-vivo or cadaveric studies were excluded. The study was carried out in accordance with PRISMA guidelines, with the search covering studies up to February 2025. RESULTS: The literature search identified 783 articles, nine of which were included in this review. A total of 343 patients were identified, of which 257 patients underwent bi-UKA. Medial and lateral osteoarthritis (OA) are the main indications for Bi-UKA. The condition of the anterior cruciate ligament (ACL) was taken into consideration by eight studies and 49 patients (19.02%) presenting functional or macroscopic intact ACL were eligible for Bi-UKA. Age was considered as an eligibility criterion in one study alone. In all studies, Bi-UKA led to the improvement of clinical scores compared to their pre-operative values. CONCLUSIONS: Both staged and simultaneous Bi-UKA are viable options to treat knee osteoarthritis. However, further research is needed to better investigate bi-UKA. LEVEL OF EVIDENCE: Level III.