Mechanical and functional properties of implanted freeze-dried flexor tendons

Tendons harvested from donor dogs were freeze-dried and implanted as free allografts in the paws of recipient experimental animals; the tendons were subsequently tested for mechanical properties, clinical function, and histologic appearance. Free tendon autografts, normal tendons in the operated experimental paw, and normal tendons in the unoperated paw were used as controls and compared with the allografts. Mechanically, the free tendon allografts and autografts were similar. The ultimate strength of the two grafts was statistically the same but significantly less, about one-third, than that of normal tendons. The implanted allografts appeared to be tolerated well by the host and to allow flexor tendon function similar to that allowed by autografts. The histologic appearance of the allograft and autograft tendons was similar at three and six months. Freeze-dried flexor tendon allografting is a satisfactory alternative to free tendon autografting.