Biologic resurfacing of the patella with quadriceps tendon flap: a rabbit study

In this experimental study, 10 rabbits underwent arthrotomy with exposure of the patellar bone (group A), 10 rabbits underwent arthrotomy of the right knee without touching the patella (group B), and 10 rabbits comprised the control group (group C), which was included only for evaluation of functional scoring activities. A 2-mm thick flap of quadriceps tendon reflected downward to cover the patellar bone denuded of cartilage, which resulted in formation of hyaline cartilage in 87% of cases in group A and 89% in group B, incomplete differentiation of the mesenchymal tissue in 7% in group A and 9% in group B, and fibrous tissue or bone formation in 6% in group A and 2% in group B. In group A, 22% of formed cartilage had a regular surface, 22% had superficial horizontal lamination, 44% had fissuring, and 12% showed severe disruption. In group B, these values were 56%, 33%, 11%, and 0%, respectively. In group A, normal cellularity was noted in 33% of cases, slight hypocellularity in 67%, and no moderate hypocellularity. In group B, these values were 56%, 33%, and 11%, respectively. This procedure should be considered in young patients with loss of articular cartilage for whom other procedures or patellectomy are unsuitable solutions.