Fig. (2) Subgroup analysis of the clinical outcome after five years as assessed by KOOS. Patients’ KOOS data were stratified according to the degenerative status of the operated knee (Kellgren-Lawrence grading 0-1 versus Kellgren-Lawrence grading of 2-3), defect size (≤ 3 cm² versus > 3 cm²), defect localization (femoral versus tibial localization), gender (females versus males), age (≤ 45 years versus > 45 years), and BMI (< 25 versus ≥ 25). The columns represent the mean and error bars define SD. Asterisks indicate significant (p < 0.05) differences.