Therapeutic effects comparison and revision case analysis of unicompartmental knee arthroplasty and open wedge high tibial osteotomy in treating medial knee osteoarthritis in patients under 60 years: a 2-6-year follow-up study - Ziqi, Z; Yufeng, M; Lei, Z; Chunsheng, W; Pei, Y; Kunzheng, W (Orthop Surg, 2020)