Fig. 2.

Representative photographs of operated joints of the sham- (a–c), meniscectomy- (d–f), and implant group (g–i). a Femoral cartilage without surface roughening after sham surgery. d, g Femoral cartilage displaying elongated surface roughening over the articulating area (black boxes) after meniscectomy and meniscal replacement. b Softening of the tibial cartilage, limited to the Eminentia intercondylaris (black arrowhead). e, h Extended softening of medial tibial cartilage (black arrowheads) after meniscectomy and meniscal replacement, including broadening of the joint surface in the implant group (dotted line). c Physiological medial meniscus of a sham animal. f Large subtotal meniscal defect and considerable cartilage erosion (dotted line). i Silk fibroin implant for subtotal medial meniscal replacement, displaying a radial rupture at the transition between the middle and posterior zone (dotted line)