Page 176 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Chapter 8
Our results suggest that cortical contact is an important factor for union of allograft-host junctions. The osteoconductive allograft acts as a sca old for host bone growth; the more contact there is between host bone and the sca old, and the closer the sca old is, the quicker incorporation may be expected26, 27. Enneking and Campanacci performed a clinicopathological study in 73 retrieved massive allografts. They observed that ‘accurate and intimate’ contact appeared to promote healing, although they described that incorporation may occur when gaps up to 4 mm are present, as long as the construct is securely immobilized28. We concur with Cascio et al, stating that attention should be paid to produce rigid, precise contact at the junction23. We recommend the use of uoroscopy in two directions to determine the degree of contact at the osteotomy level, and suggest that a revision of plate xation or addition of a second plate should be performed in cases in which less than 50% of cortical contact is observed intraoperatively.
In conclusion, the results of this study indicate that the degree of contact at the allograft-host junction is the most important factor for the risk of nonunion. Other factors that may contribute to the risk of nonunion are diaphyseal localization and patient age. Our novel classi cation system of grading allograft-host contact closely correlated with clinical outcome and demonstrated good interrater reliability. Although future, larger studies will have to con rm our ndings, this study suggests that care should be taken to obtain rm cortical contact at the junction.
Note: we thank Prof. A.H.M. Taminiau, emeritus professor at the Department of Orthopaedic Surgery of the Leiden University Medical Center, and Prof. D.L. Muscolo, professor at the Department of Orthopaedic Surgery of the Italian Hospital of Buenos Aires, for operating on a substantial number of patients included in this study.
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