UKA or HTO? What, why, and when

BACKGROUND: Medial compartment OA is the most frequent pattern of knee degeneration. When conservative options such as physical therapy or injections are exhausted, joint-preserving or resurfacing procedures become indicated. This review compares unicompartmental knee arthroplasty (UKA) and opening-wedge high tibial osteotomy (OWHTO) in terms of indications, biomechanics, outcomes, and complications, providing practical guidance for patient-specific decision-making.METHODS: A structured review of PubMed, Scopus, and Web of Science (2000-2025) was performed following PRISMA-ScR guidelines standards.RESULTS: UKA achieves superior early recovery and kinematic restoration in well-selected elderly patients, whereas OWHTO provides long-lasting joint preservation in younger, active patients.CONCLUSIONS: The choice between UKA and OWHTO must be individualized. These techniques should be viewed as sequential steps in a continuum of care rather than as competing interventions.