The present invention has multiple aspects. In its simplest aspect, the present invention is directed to an intermediate
bone block comprising a machined segment of
cortical bone,
cancellous bone or both, the intermediate having a face comprising one to ten compression surfaces and one to ten cavities, the compression surfaces suitable for compressing
soft tissue, the cavities for receiving and holding overflow
soft tissue. The cavities are preferably channels, and more preferably channels having an
omega cross-sectional profile. Surprisingly, the cavities and channels, which reduced the compressed surface area between the intermediate
bone block and the
tendon, significantly improved
tendon load at failure. In standardized tests, an intermediate
bone block of this invention, when combined with
high surface area bone blocks of the prior art bone blocks, unexpectedly increased their load at failure. The invention is also directed to bone block assemblies suitable for binding to a
soft tissue to form an implantable graft, and to such implantable grafts. A particularly preferred graft is a bone-
tendon-bone graft.