Abstract:[Objective] To compared the clinical outcome of mobile bearing (MB) and fixed bearing (FB) platforms in unicompartmentalknee arthroplasty (UKA) in the treatment of medial compartment osteoarthritis of the knee. [Methods] A retrospective study was conductedon 102 patients who received UKA for medial compartment osteoarthritis of the knee in our hospital from January 2020 to January 2023. Ac-cording to preoperative doctor-patient communication, 54 patients received MB prosthesis and 48 patients received FB prosthesis. The peri-operative period, follow-up and imaging data of the two groups were compared. [Results] All patients in both groups had UKA performed suc-cessfully with no significant differences in operation time, incision length, intraoperative blood loss, postoperative drainage volume, walkingtime and hospital stay between the two groups (P>0.05). However, the treatment cost in MB group was significantly lower than that in FBgroup [(5.1±0.2) 10k yuan vs (5.5±0.3) 10k yuan, P<0.001]. The mean follow-up time was of (26.5±3.0) months, and there was no significantdifference in the time to regain full weight-bearing activities between the two groups (P>0.05). The VAS score, WOMAC score, HSS scoreand extension-flexion range of motion (ROM) were significantly improved in both groups over time postoperatively (P<0.05), whereas whichwere not statistically significant between the two groups at any corresponding time points (P>0.05). As for imaging, femorotibial angle (FTA),hip-knee-ankle (HKA) and medial proximal tibial angle (MPTA) were significantly improved in both groups at the latest follow-up com-pared with those preoperatively (P<0.05), whereas there were no significant changes in posterior tibial slope (PTS) (P>0.05). At any timepoints accordingly, there were no significant differences in the above image indicators between the two groups (P>0.05). [Conclusion] TheMB UKA and FB UKA achieve comparable clinical consequences for medial compartment osteoarthritis of the knee.