In vivo evaluation of autologous cartilage fragment-loaded scaffolds implanted into equine articular defects and compared with autologous chondrocyte implantation.

BACKGROUND: Current autologous chondrocyte implantation (ACI) techniques require 2 surgical procedures: 1 for cell harvest and 1 for reimplantation of cultured cells. A 1-step procedure is more desirable.
PURPOSE: A 1-step surgical procedure using autologous cartilage fragments on a polydioxanone scaffold, or CAIS (cartilage autograft implantation system), in a clinically relevant defect (15-mm diameter) within equine femoral trochlea was compared with a 2-step ACI technique as well as with empty defects and defects with polydioxanone foam scaffolds alone. STUDY
DESIGN: Controlled laboratory study.
METHODS: Ten skeletally mature horses were used. Articular cartilage from the lateral trochlea of the femur was harvested arthroscopically (n = 5), and chondrocytes were cultured on small intestinal submucosa to produce ACI constructs. The CAIS procedure had cartilage harvested during defect creation to prepare minced cartilage on polydioxanone-reinforced foam. The ACI and CAIS constructs were placed in defects using polydioxanone/polyglycolic acid staples. Defects were examined arthroscopically at 4, 8, and 12 months and with gross, histological, and immunohistochemical examination at 12 months.
RESULTS: Arthroscopic, histologic, and immunohistochemistry results show superiority of both implantation techniques (ACI and CAIS) compared with empty defects and defects with polydioxanone foam alone, with CAIS having the highest score.
CONCLUSION: This is the first demonstration of long-term healing with strenuous exercise using ACI and CAIS in a critically sized defect. CLINICAL RELEVANCE: Given these results with the CAIS procedure, testing in human patients is the next logical step (a phase 1 human clinical study has proceeded from this work).