Histologic analysis

After euthanasia, each knee was carefully stripped from the surrounding soft tissues except from the autograft itself (Fig. 3). For histopathologic examination of the knee joints, each sample was fixed in 10% buffered formalin. The specimens were decalcified in a decalcifying agent (Calci-Clear Rapid, National Diagnostics, GA) for 12 hours, cut along the grafted tendon in the oblique-sagittal direction, and embedded in paraffin. The paraffin block were sectioned at a 3 μm thickness using a microtome (Leica Microsystems, Inc, Wetzlar, Germany) and each section was stained with Hematoxylin and Eosin (H & E). The stained slides of the knee joint sections were observed under a light microscope and were read by a pathologist.

(A) Gross photo and (B) oblique-sagittal section appearance showing reconstruced ACL on knee joint of rabbit.