An in vivo study of a growth-factor enhanced, cell free, two-layered collagen-tricalcium phosphate in deep osteochondral defects.
Focal osteochondral defects are still a challenging problem in joint surgery. We have developed a two-layered implant consisting of a basal porous beta-tricalcium phosphate (TCP) for bone reconstruction and a superficial fibrous collagen type I/III layer for cartilage regeneration. Fifty-four osteochondral defects in the trochlear groove of 27 Göttinger Minipigs were created and either left untreated, treated with the implant alone, or the implant augmented with an additional growth factor mixture, which was assumed to stimulate cell and tissue differentiation. Follow-up was 6, 12 and 52 weeks with n=6 for each group. The repair tissue was evaluated for its gross appearance and biomechanical properties. Histological sections were semi-quantitatively scored for their histomorphological structure. Treatment with the two-layered implant improved defect filling and subchondral bone repair at 6 and 12 weeks follow-up. The TCP was replaced by cancellous bone at 52 weeks. Cartilage repair tissue mainly consisted of fibrocartilage and showed a moderate cell density up to the joint surface. Growth factor treatment improved the mechanical and histomorphological properties of the cartilage repair tissue at 12, but not at 52 weeks postoperatively. In conclusion, the two-layered collagen-TCP implant augmented with chondroinductive growth factors seems a promising new option for the treatment of deep osteochondral defects in joint surgery.
Department of Orthopaedics, University of Heidelberg, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany. T.Gotterbarm@gmx.de
Tobias
T
Gotterbarm
Wiltrud
W
Richter
Martin
M
Jung
Simona
S
Berardi Vilei
Pierre
P
Mainil-Varlet
Takeshi
T
Yamashita
Steffen J
SJ
Breusch
D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000737:chemistry / Q000627:therapeutic use; D001842:Bone and Bones / Q000473:pathology / Q000502:physiology; D002130:Calcium Phosphates / Q000737:chemistry* / Q000627:therapeutic use; D002358:Cartilage, Articular / Q000473:pathology / Q000502:physiology; D003094:Collagen / Q000737:chemistry* / Q000627:therapeutic use; D005260:Female; D006133:Growth Substances / Q000737:chemistry* / Q000627:therapeutic use; D007719:Knee Joint / Q000473:pathology; D008297:Male; D010007:Osteochondritis / Q000473:pathology / Q000628:therapy*; D019736:Prostheses and Implants; D012038:Regeneration; D013552:Swine; D013556:Swine, Miniature
D018786:Bone Substitutes; D002130:Calcium Phosphates; D006133:Growth Substances; C485817:beta-tricalcium phosphate; D003094:Collagen