IMMUNE-RESPONSE INHIBITION BY IRRIGATING SUBCHONDRAL BONE WITH CYTOTOXIC AGENTS

Attempts have been made (in the recent past) to inhibit the immune res ponse to fresh osteoarticular (shell) allografts because the occurrenc e and the magnitude of this response is considerably greater and more harmful than that seen after frozen bone and soft tissue allografts, T o decrease the immunogenicity of these fresh grafts, the subchondral b one of rat distal femur allografts was irrigated with Betadine scrub s olution (n = 10) or Triton-X (n = 11) before transplantation (Study 1) . The Triton-X significantly reduced the immunogenicity of the grafts, but the Betadine scrub solution had no effect, A similar experiment w ith Triton-X was done in sheep where trochlear knee autografts (n = 3) were compared with unirrigated allografts (n = 3) and allografts rece iving irrigation with Triton-X (n = 3) (Study 2). All 3 Triton-X irrig ated allografts had no immune response, and showed much improved graft s compared with the control allografts (where an immune response devel oped in 2 of 3), Neither of the 2 allograft groups were as good as the autografts. These techniques may prove useful for inhibiting the reci pient immune responses to fresh osteoarticular allografts in humans re quiring partial joint reconstruction.