Figure 3: Gross morphological (A1–B4) findings of the subscapularis tendons in groups 1, 2, 3, and 4. (A1–A4) Pretreatment images. FTT is observed in all four groups. (B1–B4) Posttreatment images. FTT is shown and no gross morphologic changes between pretreatment and four weeks posttreatment in G1-SAL and G2-PDRN. There are significant differences in gross morphologic changes between pretreatment and four weeks posttreatment in G3-MSC and G4-MSC + PDRN. Normal saline (0.2 mL; group 1: SAL), PDRN (0.2 mL; group 2: PDRN), MSC (0.2 mL; group 3: MSC), and MSCs with PDRN (both 0.2 mL; group 4: MSC + PDRN). MSC: human umbilical cord blood-derived mesenchymal stem cell; PDRN: polydeoxyribonucleotide; FTT: full-thickness tendon tear.