Page 167 - Reconstructive Techniques in Musculoskeletal Tumor Surgery

Introduction
Primary malignant bone tumors of the metadiaphyseal or diaphyseal region of the long bones may be treated with joint-preserving intercalary resections1, 2. Many techniques have been described for reconstruction after such resections, of which allografts have been most commonly used. Nevertheless, intercalary allografts have been associated with substantial rates of complications. Nonunion is among the major complications (15-55%)1, 3-10 and failure mechanisms (5-7%) of these reconstructions1, 6.
Nonunion is assumed to result from a complex interplay between biological and mechanical factors, and its treatment is often problematic because one side of the junction is comprised of nonvascular bone11. Factors that have been associated with the risk of nonunion include the site of transplantation, use of chemotherapy, radiotherapy, patient age, localization of the osteotomy, and the use of intramedullary nails instead of plates1, 3, 6, 8, 11. In addition, it has been reported that failure to achieve stable xation or bone contact at the junction may result in nonunion12. However, most studies included small patient groups with heterogeneous reconstructions, and con icting results have been reported. Therefore, there is little solid evidence on risk factors for nonunion.
With this study, we aimed to evaluate the incidence of, and risk factors for,
nonunion in intercalary allograft reconstructions of weight-bearing bones. 8 Moreover, we aimed to evaluate if cortical contact at the allograft-host junction
results in a decreased likelihood of nonunion.
Patients and Methods
Patient selection
We present a retrospective case series of all patients with an intercalary (whole- circumference) allograft reconstruction for a primary bone tumor of the femur or tibia, from two tertiary referral centers of orthopaedic oncology. From center one, patients who had their operations between 1989 and 2012 were included. From center two, we only included patients who had their operations between 2008 and 2012 because before that time, digital radiographs were not available, and contact at the allograft-host junction could therefore not be determined in a uniform matter. Our primary end-point was union of the allograft-host junction.
Allograft nonunion
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