FELINE MODEL FOR THE STUDY OF FROZEN OSTEOARTICULAR HEMIJOINT TRANSPLANTATION - QUALITATIVE AND QUANTITATIVE ASSESSMENT OF BONE HEALING

Abstract

Outbred cats (24) underwent massive osteoarticular allograft and control autograft transplantation, using the right distal femur with its articular cartilage, capsule, and medial collateral ligament intact. The cats were monitored clinically and radiographically for 1 yr. Groups of cats (4 allografts and 2 control autografts) were euthanatized at 3-, 6-, 9- and 12-mo. intervals. At necropsy, the grafts were photographed and assessed for bone healing and replacement by standard radiography, quantitative 99mTc bone scans, microradiograhy and histologic examination of decalcified and nondecalcified specimens. The osteosynthesis site of the allografts usually healed by 5 mo., compared with the autografts that healed by 3 mo. As illustrated by quantitative bone scans, creeping appositional new bone slowly invaded and replaced the allograft bone. Seemingly, the cat can be used as an acceptable and clinically comparable model for the massive osteoarticular allografts currently being used for the reconstruction of joints damaged or destroyed by neoplasm surgery in limb-sparing procedures in human beings. This model may also be used to assess the rate and method of bone healing.