Cancellous impaction grafting in the human femur - Histological and radiographic observations in 6 autopsy femurs and 8 biopsies

6 whole postmortem femurs and 8 femoral biopsies were studied histologicall y, 3 months to 8 years after cancellous impaction grafting with a cemented stem for aseptic loosening, All stems were stable. Radiographs showed corti cal healing in 5 cases, trabecular remodelling in 1, and trabecular incorpo ration in 9. There was a radiolucent line in 1 case. The histology varied. There was always a viable cortical shell around the g rafted area. 1 patient showed complete bony restitution. The others still h ad varying amounts of remaining graft in the neo-medullary cavity, even aft er 8 years. The graft particles were usually em bedded in dense fibrous tis sue, thus forming a supporting composite tissue capable of carrying load, T here was no time-dependent deterioration in the histological appearance. Radiographically, cortical healing and trabecular remodeling corresponded t o viable bone, The lack of a ra diolucent line said little about the viabil ity of the tissue closest to the cement. The radiographs did not detect thi n soft tissue membranes, Radiographic criteria used to assess primary total joint replacement do not necessarily apply to impaction grafting, and radiographic changes should b e interpreted cautiously, especially as regards tissue viability.