title: Matrix-guided cartilage regeneration in chondral defects.
abstract: Small cartilage defects treated with microfracture show comparable clinical results to those treated with ACI (autologous chondrocyte implantation). Unfortunately, the regenerative tissue generated by microfracture treatment does not exhibit the structure and function of hyaline articular cartilage. Adult mesenchymal stem cells are supposed to be capable of differentiating according to mechanical stimuli, e.g. into chondrocytes, thus generating hyaline cartilage. The treatments used so far, such as the microfracture procedure, are only able to induce mechanically insufficient fibrocartilage. The purpose of the present study was to test the influence of a resorbable implant manufactured from PGLA (polyglycollic-co-lactic acid) fleece in combination with microfracture in the weight-bearing area of the femoral condyle of mature sheep on cartilage repair. Artificial chondral defects (diameter: 8 mm) were created and treated with microfracture, with a PGLA implant alone or with a combination of both (n=6 for each group). Untreated empty defects served as controls. Under thorough pain control, full weight bearing was permitted immediately after the operation. After 12 weeks, the animals were killed and the operated knees were removed and histologically processed. First, the degree of covering of the defect with regenerative tissue was measured; then, the quality of the regenerate was evaluated using the score of O'Driscoll, Keeley and Salter [(1986) J. Bone Joint Surg. Am. 68, 1017-1035], which was modified to include histochemical labelling results. The combination of PGLA implant and microfracture led to a significant improvement of the quality of the regenerate when compared with microfracturing alone.
authors.affiliation: Department of Orthopedics, Campus Grosshadern, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377 Munich, Federal Republic of Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wegener
authors.forename: Florian M
authors.initials: FM
authors.lastname: Schrimpf
authors.forename: Mathias F
authors.initials: MF
authors.lastname: Pietschmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Milz
authors.forename: Meike
authors.initials: M
authors.lastname: Berger-Lohr
authors.forename: Philipp
authors.initials: P
authors.lastname: Bergschmidt
authors.forename: Volkmar
authors.initials: V
authors.lastname: Jansson
authors.forename: Peter E
authors.initials: PE
authors.lastname: Müller
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D054544:Arthroplasty, Subchondral; D002358:Cartilage, Articular / Q000166:cytology / Q000293:injuries* / Q000502:physiology* / Q000648:ultrastructure; D019902:Chondrocytes / Q000166:cytology / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D048091:Guided Tissue Regeneration / Q000379:methods*; D020007:Implants, Experimental; D019344:Lactic Acid / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012756:Sheep; D018709:Statistics, Nonparametric; D013264:Stifle / Q000473:pathology; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen