Overlapping allograft for primary or salvage bone tumor reconstruction

Background Compared with end-to-end allograft coaptation, overlapping allograft offer a superior union rate by increasing the contact area. However, reports on overlapping allograft are scarce. Therefore, we attempted to confirm the usefulness of this technique either after primary tumor resection or in salvaging a failed reconstruction. Methods We analyzed the outcome of 35 overlapping allografts reconstructions. Indications were primary reconstruction of a skeletal defect (n=19) and salvage of a failed reconstruction (n=16). Graft survival, union rate, and time to union were evaluated as a function of clinical variables such as age, use of chemotherapy, type of junction, method of fixation, length of overlapped bone, and method of overlapping. Results All 35 overlapping allografts showed union at a mean of 5.6 months (range, 3-14 months). One allograft was removed with local recurrence at 19 months post-operatively. Average length of overlapped bone was 3.5cm (range, 1.4-6.5cm). Patient age <15-years (P=0.001) and circumferential overlapping (P=0.011) shortened the time to union. Conclusions In terms of graft failure rate, union rate, and time to union, overlapping allograft is an excellent technique, which overcomes the limitations of end-to-end fixation. J. Surg. Oncol. 2014; 110:366-371. (c) 2014 Wiley Periodicals, Inc.