ABSTRACTObjectiveCompare the results of medial unicompartmental knee arthroplasty (UKA) using a mobile platform and total knee arthroplasty (TKA) in patients with isolated medial osteoarthritis.MethodsRetrospectivecross-sectional study. Preoperative radiographs of 602 patientswho underwent knee arthroplastybetween February 2017 and February 2020 were evaluated. Isolated medial osteoarthritis was found in 125 patients. Of these, 57 underwent UKA and 68 TKA. With chart analysis and telephone interviews, we compared patients’ clinical outcomes and degree of satisfaction. The statistical analysis used a confidence level of 5%.ResultsThe group of UKA patients obtained 65.8% of favorable results against 79.1% of those undergoing TKA in the function questionnaire (p<0.0001). The complication rate was statistically similar between the groups(p>0.5). Most patients were satisfied or very satisfied in both groups (88.6% of UKA and 91.2% of TKA) (p>0.999).ConclusionPatients submitted to UKA or TKA have presented the same degree of satisfaction and rate of postoperative complications when comparing patients with isolated medial osteoarthritis. UKA patients had less favorable results onthe clinical functional questionnaire than patients undergoing total arthroplasty. Level Of Evidence III;Retrospective Study.