Abstract:To explore the clinical effect of arthroscopic exploration in medial unicondylar replacement of knee osteoarthritis (OA). Methods Arthroscopy-assisted medial unicondylar arthroplasty was performed in 36 patients who met the criteria for medial unicondylar arthroplasty of the knee joint, then observe the curative effect. Results All these cases were followed up effectively. All the patients' pain was relieved effectively. X-ray showed that the prosthesis position was good, the lower limb force line was restored, the pain and deformity of knee joint were alleviated, and the range of motion of joint was good. The average score of knee joint function before and after operation was (60.3 ± 5.1) point and (91.1 ± 3.2) point. There were significant differences in knee score (HSS) before and after surgery (t = 30.13, P = 0.002); preoperative range of motion (105.3 ± 5.6)°, and postoperative range of motion (116.2 ± 4.2)°. The difference was statistically significant (t = 10.29, P = 0.004). The preoperative inversion angle of the weight-bearing position (12.3 ± 3.0)°, it was significantly different from that of the postoperatively average (3.5 ± 2.1)° (t = 12.35, P = 0.003). Conclusion Arthroscopy can effectively observe the structural integrity of the lateral compartment of knee joint and patellofemoral joint before unilateral condylar replacement, improve the evidence support for unilateral condylar replacement, at the same time, deal with the meniscus, synovium and free body of the lateral compartment, effectively improve the internal environment of the lateral compartment, and alleviate arthritis, compression, pain and further improve the effect of UKA.