title: Maturation-dependent spontaneous healing of partial thickness cartilage defects in infantile rats.
abstract: Partial-thickness articular cartilage defects (PTCDs) do not heal spontaneously and are thought to be a predisposing factor for the development of osteoarthritis. Younger and smaller animals have a better healing capacity for many types of injuries including those to articular cartilage. Our aim was to examine the longitudinal histological changes of immature murine articular cartilage after the creation of small PTCDs and to compare them to PTCDs in mature cartilage. Single linear PTCDs were created in 3-week-old and 16-week-old rats in the direction of joint motion. At 6 and 12 weeks after PTCD creation, histological changes were examined in the defect sites and surrounding cartilage. Immature cartilage showed a higher repair capability than mature cartilage. Although repaired immature cartilage had fibrocartilage, it exhibited better quality than any PTCD model, except for a fetus model and comparable quality to full-thickness cartilage defects (FTCD) after bone marrow stimulation. Elucidation of the underlining mechanisms that immature cartilage possesses for repairing PTCDs is necessary in order to aid the prevention or develop treatment for osteoarthritis.
authors: Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors: Hiroaki
authors: H
authors: Tsuruoka
authors: Takahisa
authors: T
authors: Sasho
authors: Satoshi
authors: S
authors: Yamaguchi
authors: Naoshi
authors: N
authors: Ikegawa
authors: Masahiko
authors: M
authors: Saito
authors: Ryuichiro
authors: R
authors: Akagi
authors: Nobuyasu
authors: N
authors: Ochiai
authors: Koichi
authors: K
authors: Nakagawa
authors: Arata
authors: A
authors: Nakajima
authors: Louay
authors: L
authors: Fallouh
authors: Kazuhisa
authors: K
authors: Takahashi
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002358:Cartilage, Articular / Q000254:growth & development* / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing