The minipig model for experimental chondral and osteochondral defect repair in tissue engineering: Retrospective analysis of 180 defects

Abstract

SummaryArticular cartilage repair is still a challenge in orthopaedic surgery. Although many treatment options have been developed in the last decade, true regeneration of hyaline articular cartilage is yet to be accomplished. In vitro experiments are useful for evaluating cell -matrix interactions under controlled parameters. When introducing new treatment options into clinical routine, adequate animal models are capable of closing the gap between in vitro experiments and the clinical use in human beings. We developed an animal model in the Gö ttingen minipig (GMP) to evaluate the healing of osteochondral or full-thickness cartilage defects. The defects were located in the middle third of the medial portion of the patellofemoral joint at both distal femurs. Chondral defects were 6.3 mm, osteochondral defects either 5.4 or 6.3 mm in diameter and 8 or 10 mm deep. In both defects the endogenous repair response showed incomplete repair tissue formation up to 12 months postoperatively. Based on its limited capability for endogenous repair of chondral and osteochondral defects, the GMP is a useful model for critical assessment of new treatment strategies in articular cartilage tissue engineering.

Bone Marrow-Derived Cell Concentrates Have Limited Effects on Osteochondral Reconstructions in the Mini Pig

“…13 Even though in this study the diameter of the defects was maximized to 7 mm, there was a large variation in the endogenous healing response. Even in the empty or upside-down cylinder group, some defects healed nearly completely after only 3 months.…”

“…14 This study has several limitations: A longer follow up of 1 year would have been desirable. 13 Differences between the groups were small and are likely to have become smaller during further follow up.…”

“…11 In animal experiments, the mini pig has been frequently used to investigate osteochondral defects, as it is known that empty defects of 6 · 10 mm or beyond cause incomplete defect regeneration within 2 years. 12,13 Different biomaterials have been implanted in these defects with or without cells. 10,14 In contrast to isolated bone defects, autologous cell-seeded constructs do not improve the histological appearance of the regenerates.…”

The effect of defect localization on spontaneous repair of osteochondral defects in a Göttingen minipig model: a retrospective analysis of the medial patellar groove versus the medial femoral condyle

“…The smallest animals used were mice 6 and rats, 7 being followed by rabbits. 8 For more advanced preclinical studies, large animal models such as dogs, 9 goats, 10 pigs 11 or horses 12 were used.…”

Isolation and characterization of mesenchymal progenitors derived from the bone marrow of goats native from northeastern Brazil

“…There are numerous animal models, such as rodents 12,15 , swine 16 and canines [17][18][19] that have been used in experiments related to cell therapies. Regarding such animals, outcomes were found in studies about neurodegenerative injuries 12,13 , as well as in attempts to use cell therapy as a way to treat cardiovascular diseases 20 .…”