Subchondral Drilling Diameter During CARTISTEM Implantation for Knee Cartilage Defects

This prospective, randomized study at Severance Hospital compares two subchondral drilling techniques during CARTISTEM implantation for symptomatic medial-compartment knee articular cartilage defects. Sixty participants will be allocated 1:1 to drilling with a 2-mm drill alone or sequential drilling with 4-mm and 2-mm drills. CARTISTEM preparation and implantation will be the same in both groups. High tibial osteotomy may be performed when needed to correct alignment. The primary endpoint is the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation score at 12 months after surgery. The study will assess non-inferiority of the 2-mm technique using a prespecified margin of 10.3 points. Secondary assessments include pain and knee function, MRI cartilage repair and subchondral bone findings, radiographic osteoarthritis and alignment, and second-look arthroscopy in participants undergoing plate removal after high tibial osteotomy.