Osteochondral Lesion of Talus

The goal of this clinical trial is to establish a multicenter prospective cohort of patients with severe osteochondral lesion of the talus (OLT), evaluate the clinical efficacy of autologous osteoperiosteal transplantation and the incidence of postoperative donor-site morbidity. The main questions it aims to answer are: Does autologous osteoperiosteal transplantation have good clinical outcomes in the treatment of severe OLT? Does autologous osteoperiosteal transplantation treat severe OLT with fewer postoperative complications? Participants will: Undergo autologous osteoperiosteal transplantation for OLT Receive clinical follow-up 3, 6, 12, and 24 months after surgery and answer scales of ankle function assessment Take CT and MRI preoperatively and 12 and 24 months after surgery

The goal of this clinical trial is to learn if combined local injection of platelet rich plasma (PRP) gel adds clinical efficacy to isolated arthroscopic microfracture in treatment of osteochondral lesion of the talus (OLT). The interface integration of the injured area will also be assessed via radiographic follow-up. The main questions it aims to answer are: * Does arthroscopic microfracture combined with PRP gel injection improve ankle function of participants based on American Orthopedic Foot and Ankle Society (AOFAS) Score? * Does arthroscopic microfracture combined with PRP gel injection improve interface integration of the injured cartilage on magnetic resonance imaging (MRI)? Researchers will compare arthroscopic microfracture with concomitant local injection of PRP gel to isolated microfracture to see if intraoperative PRP gel injection adds clinical efficacy to isolated arthroscopic microfracture in treatment of OLT. Participants will: * Undergo either isolated arthroscopic microfracture or microfracture with intraoperative injection of PRP gel * Receive clinical follow-up 3, 6, 12, and 24 months after surgery and answer scales of ankle function assessment * Take MRI preoperatively and 6, 12 and 24 months after surgery