title: The effect of defect localization on spontaneous repair of osteochondral defects in a Gottingen minipig model: a retrospective analysis of the medial patellar groove versus the medial femoral condyle.
abstract: Various animal models for experimental osteochondral defect healing have been used in orthopaedic research. Two main defect locations were chosen: the patellar groove or the central part of the medial femoral condyles (MFC). To date, it is not clear whether both locations display similar patterns in critical size osteochondral defect healing. We retrospectively analysed both locations in our minipig model hypothesizing that they show similar healing pattern. Thirty-five defects were analysed after three or 12 months. Osteochondral defects were 10 mm deep and 6.3 mm (MFC, n = 19) in diameter or 8 mm and 5.4 mm, respectively (trochlear groove [TG], n = 16). Semi-quantitative histological scoring and histomorphological evaluation were carried out. Both defect locations showed fillings of fibrous and fibrocartilage-like repair tissue. The osseous defect was closed by endochondral bone formation in the MFC. Semi-quantitative scoring did not show differences, whereas qualitative histomorphological analysis more frequently showed cartilaginous repair tissue in MFC defects. There was more frequent subchondral bone cyst formation in MFC location (P = 0.05), TG defects resulted in lower postoperative pain. Both defect localizations are suitable for studies on osteochondral healing. Since regenerating with less hyaline-like repair tissue and less subchondral cyst formation, TG is more favourable for experimental osteochondral defect healing in this model.
authors.affiliation: Orthopaedic University Hospital Heidelberg, Schlierbacher Landstr. 200a, 69118 Heidelberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Jung
authors.forename: Steffen
authors.initials: S
authors.lastname: Breusch
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Daecke
authors.forename: Tobias
authors.initials: T
authors.lastname: Gotterbarm
mesh_terms: D000818:Animals; D001847:Bone Diseases / Q000473:pathology*; D001861:Bone Regeneration; D002357:Cartilage Diseases / Q000473:pathology*; D004195:Disease Models, Animal; D005260:Female; D005269:Femur / Q000502:physiology* / Q000601:surgery; D006651:Histocytochemistry; D008297:Male; D010329:Patella / Q000502:physiology* / Q000601:surgery; D012189:Retrospective Studies; D013552:Swine; D013553:Swine Diseases / Q000473:pathology*; D013556:Swine, Miniature; D014945:Wound Healing / Q000502:physiology*