Treatment of Osteochondral Defects with Perichondrial Cells Embedded in Alginate Beads in Rabbit

Ahn, Hyun Jeong; Kim, Eun Mi; Jung, Mee Hyun; Jo, Hyun Chul; Lee, In Bum; Seong, Sang Cheol; Lee, Myung Chul

Abstract

PURPOSE
The objective of this study was to investigate the use of cultured rib perichondrial cells embedded in alginate bead on healing in a rabbit osteochondral defect model. The degree of articular cartilage repair was evaluated histologically, histomorphometrically, and biochemical characteristics of the neocartilage.
MATERIALS AND METHODS
A single defect, 3.5 mm wide by 3 mm deep, was created in the weight bearing area of the medial femoral chondyle in thirty New Zealand rabbits. The right defect filled with two alginate beads embedded with rabbit rib perichondrial cells, the left defect was empty as the control. The animals were killed at 1, 3, and 12 months, and the repair tissues were examined histologically, and histomorphometric differences were evaluated by an image analysis system. The defects also were examined biochemically for the glycosaminoglycan (GAG) and type II collagen to compare the results with normal articular cartilage.
RESULTS
The attachment of repair tissue with the surrounding host tissue was incomplete, many specimens exhibited degenerative changes in adjacent tissue over a post transplant time period. Histomorphometric results showed that the repair groups (0.24+/-0.11 mm, -26.97 (25.62 mm) was decreased in surface roughness, and depression than controls (0.32+/-0.06 mm, -48.73 (32.59 mm) at 12 months. Repair area, repair area ratio, and repair thickness of the repair groups (6.89+/-2.1 mm2, 39.5+/-19.5%, 0.11 (0.01 mm) were increased than controls (2.65+/-2.35 mm2, 2.85+/-2%, 0.09+/-0.04 mm) at 12 months. After 12 months, the content of GAGs of neocartilage (36.45 microgram/mg) was similar to those of normal artilcular cartilage (36.74 microgram/mg), the percentage of type II collagen of the neocartilage increased up to 95%.
CONCLUSION
Transplanted rib perichondrial cells were seen to proliferate to fill the osteochodral defect with neocartilage. Histomorphometric analysis should allow a more quantitative described the degree of articular cartilage repair.