The promising potential of intra-articular losartan combined with scaffold implantation for osteochondral repair: a comparative study in a rabbit model against osteochondral autograft transplantation.

Purpose: This study aimed to compare the radiological, macroscopic, biomechanical and histological outcomes of osteochondral autograft transplantation (OAT) and a combination of intralesional scaffold with intra-articular losartan injection in a rabbit model of osteochondral injury. Methods: Twelve rabbits received bilateral osteochondral defects (4 × 4 mm) in the trochlear region of both knees and were divided into two groups. Group A received scaffold implantation with intra-articular losartan (1 mg per knee, injected in 0.1 mL of solution), while Group B underwent OAT with re-implantation of the original plug. After 6 months, bilateral knee magnetic resonance imaging (MRI), macroscopic, histological and biomechanical assessments were performed. Results: Macroscopic examination demonstrated that the defect areas were filled and integrated with the surrounding cartilage. MRI evaluations revealed complete closure of the osteochondral defects. Histological evaluation using Wakitani scores showed no statistically significant difference between the groups (Group A: 3.63 ± 2.13, Group B: 2.63 ± 2.01, p = 0.423). Finally, no significant difference was observed in biomechanical load testing between the groups (Group A: 219.2 ± 72.9 N, Group B: 270.8 ± 67.6 N, p = 0.149). Conclusions: The scaffold-losartan combination may offer a promising, less invasive alternative to traditional OAT for osteochondral defect repair. Level of Evidence: N/A.