Limited integrative repair capacity of native cartilage autografts within cartilage defects in a sheep model

Abstract

The purpose of this study was to investigate integration and cellular outgrowth of native cartilage autografts transplanted into articular cartilage defects. Native cartilage autografts were applied into chondral defects in the femoral condyle of adult sheep. Within the defects, the calcified cartilage layer was either left intact or perforated to induce bone marrow stimulation. Empty defects served as controls. The joints were analyzed after 6 and 26 weeks by macroscopic and histological analysis using the ICRS II Score and Modified O'Driscoll Scores. Non-treated defects did not show any endogenous regenerative response and bone marrow stimulation induced fibrous repair tissue. Transplanted native cartilage grafts only insufficiently integrated with the defect borders. Cell death and loss of proteoglycans were present at the margins of the grafts at 6 weeks, which was only partially restored at 26 weeks. Significant cellular outgrowth from the grafts or defect borders could not be observed. Bonding of the grafts could be improved by additional bone marrow stimulation providing ingrowing cells that formed a fibrous interface predominantly composed of type I collagen. Transplanted native cartilage grafts remain as inert structures within cartilage defects and fail to induce integrative cartilage repair which rather demands additional cells provided by additional bone marrow stimulation. ß

Cationic contrast‐enhanced computed tomography distinguishes between reparative, degenerative, and healthy equine articular cartilage

“…Repair 1 tissue retains calcified cartilage in the defect. This technique is not used clinically because of the minimal tissue ingrowth with inferior tissue quality that forms, 24,37 as was corroborated by this study. Because we performed gentle debridement to retain calcified cartilage in Repair 1 defects, some noncalcified deep articular cartilage may have remained, 38 though it was not detected on histologic review.…”

“…Because we performed gentle debridement to retain calcified cartilage in Repair 1 defects, some noncalcified deep articular cartilage may have remained, 38 though it was not detected on histologic review. The Repair 2 group imitates calcified cartilage removal as would be performed before microfracture and marrow stimulation procedures used clinically 24,37 . The resultant tissue is fibrous to fibrocartilaginous on histological assessment.…”

Stimulation of a calcified cartilage connecting zone by GDF‐5‐augmented fibrin hydrogel in a novel layered ectopic in vivo model

“…Early implant loss and delamination are major challenges when fixing cartilage tissue engineering implants in cartilage defects via adhesives . Considering the central mechanical function of cartilage, early restoration of the physical hardness by stimulating calcification at the bottom of the repair tissue seems highly favorable.…”

“…Early implant loss and delamination are major challenges when fixing cartilage tissue engineering implants in cartilage defects via adhesives. [39][40][41] Considering the central mechanical function of cartilage, early restoration of the physical hardness by stimulating calcification at the bottom of the repair tissue seems highly favorable. Early formation of a robust intermediate layer of calcified cartilage has, thus, high potential to increase primary stability and mechanical resilience of the replacement tissue.…”

Creating Cartilage in Tissue-Engineered Chamber Using Platelet-Rich Plasma Without Cell Culture

“…After physically cutting the cartilage, small pieces of cartilage show outgrowth at the cutting edge in vivo 28 and in vitro. 29,30 Although some researchers have shown limited outgrowth, 31,32 no researchers have used scaffolds to optimize regeneration. Additionally, the reported observation times have always been <7 days, which is not sufficient for outgrowth.…”