To evaluate the biologic changes of xenograft (Lubboc, Transphyto S. A., Clermont-Ferrand, France) applied in the surgical treatment of calcaneal fractures.

Xenograft were used in twenty-five calcaneal fractures, as bone substitutes for mechanical support of the articular surface from March 1994 to December 1996. Twenty-four cases had obtained clinical and radiological bony union without complications. We performed biopsy at the xenograft area in eight cases when the hardware was removed. And then we took a magnetic resonance imaging of the calcaneus after the biopsy in three cases.

The pathologic findings of the xenografts showed dead bony trabeculae with inflammed fibrous tissue. There was no osteoblastic activity but some osteoclastic activity was seen in the graft-host junctional area. MRI findings showed that there was well-circumscribed, low-signal intensity in the xenograft area contrast to the normal bony signal intensity. Its lesion was equal to the sclerotic finding in the calcaneal radiograph.

Xenograft (LUBBOC'), which is used in the mechanical support of the articular surface, apparently lacks osteogenic capacity.