Jay S. Wunder

Background: The Reconstructive Allograft Preparation by Toronto Sarcoma (RAPTORS) protocol is reliable and reproducible without substantially adding to the surgical reconstruction time or cost. Our technique includes clearance of debris, lavage of the medullary canal, pressurized filling of the medullary canal with antibiotic-laden cement for its mechanical and antimicrobial properties, and insertion of cancellous autograft at the allograft-host junctional ends prior to dual-plate compression to fix the allograft into the defect 1–3 . Our experience with large intercalary allograft reconstruction has demonstrated high rates of long-term success and addresses the most common causes of large allograft failure (infection, fracture, and nonunion) 4 , as shown in our long-term outcome study 1 . Description: Once the tumor is resected, it is used as a template for cutting and shaping the allograft to fit the bone defect and to restore length and anatomy. The frozen allograft is thawed in a container with povidone iodine and bacitracin saline solution until it reaches room temperature. The allograft is size-matched, and clearance of its intramedullary marrow contents is performed with use of curets and intramedullary reamers 7 . If 1 end of the allograft includes the metaphysis and is covered by dense cancellous bone, we try not to ream through this end because maintaining this metaphyseal cancellous surface will expedite bone healing. The segment is then thoroughly lavaged with “triple wash” solutions to clear out any remaining marrow contents and to ensure sterilization of the allograft. This serial-wash technique involves the use of 3 discrete antiseptic modalities and has been utilized at our institution with low rates of allograft infection. These antiseptic modalities include 10% weight-per-volume povidone iodine diluted 1:1 with normal saline solution, 3% weight-per-volume hydrogen peroxide diluted 1:1 with normal saline solution, and 50,000 units of sterile bacitracin lyophilized powder dissolved in 500 mL of normal saline solution. Following the triple wash, the medullary canal is filled with antibiotic-laden methylmethacrylate bone cement. If both ends are open, the far end of the segment is first plugged with the surgeon’s finger or with gauze, or if 1 end is covered with cancellous bone, then retrograde filling of the canal with cement is performed from the open end. The cement is then pressurized to ensure complete filling of the intramedullary space. Before it sets, 1 cm of cement is removed from each open end of the allograft to allow for packing of autograft bone cancellous chips and to ensure that cement does not impede anatomic reduction of the allograft-host bone junction. For this step, cancellous autograft from the iliac crest is harvested with use of a separate sterile surgical setup in order to prevent contamination of the autograft site by instruments used for tumor resection. The cancellous autograft is packed into the space created after recessing the cement at the end(s) of the allograft and, using a bone tamp, the autograft is compressed into this cavity and into the corresponding end of the host long bone in order to improve the healing potential at the allograft-host bone junction(s) 8 . Finally, a dual compression plate construct is utilized for upper as well as lower-extremity reconstruc