Distraction Osteogenesis and Ramus Onlay Bone Grafting using Autologous Platelet Concentrate Enriched with Growth Factors (APC+) CRAIG M. MISCH, DDS, MDS Sarasota Medical Center 5741 Bee Ridge Road, Suite 220, Sarasota, FL 34233 Phone: 941-379-4244, Fax: 941-379-5764, e-mail: email@example.com INTRODUCTION A 38 year old female was involved in a motor vehicle accident and suffered several injuries including a mandible fracture and traumatic avulsion of several mandibular and maxillary teeth. These injuries re- sulted in scarring and severe alveolar bone loss especially in the ante- rior mandible (Figs. 1, 2). The patient was referred to Dr. Craig Misch for treatment of the injuries. OBJECTIVE Figure 1 Figure 2 The patient was offered three options to reconstruct the mandibular defect including: 1) implant placement in the residual mandible and restoration with a fixed detachable prosthesis; 2) iliac bone grafting to reconstruct the defect and implant placement for a fixed bridge; or 3) osseous distraction of the anterior mandible to repair the vertical bone defect followed by onlay grafting with intraoral bone to place implants for a fixed bridge. The patient had suffered pelvic injuries and declined the iliac bone graft option. She preferred reconstruction of the defect and an implant bridge so distraction osteogenesis was planned. The scar tissue from the injury limited lip movement and was a healing concern. Figure 3 Figure 4 Figure 5 MATERIALS AND METHODS Approximately 50cc of intravenous blood was drawn pre-operatively and processed using an automated dual spin process (SmartPRePTM, Harvest Technologies, Inc., Plymouth, MA). The 12 minute process produced 10cc of autologous platelet concentrate enriched with growth factors (APC+) and approximately 20cc of platelet poor plasma (PPP). A vestibular incision was made in the anterior mandible and the bone plate from the fracture repair was removed. The mandible fracture had healed well. Osteotomies were performed with a sagittal saw to allow distraction of the pedicled ossicle in the anterior mandible (Fig. 3). A distraction device (KLS Martin, LP) was adapted to the mandible and fixated into place (Fig. 4). APC+ was injected between the osteotomies and over the device (Fig. 5) to accelerate bone development. Figure 6 Figure 7 Figure 8 Following a six day latency period distraction of the ossicle was begun. The segment was moved verti- cally 9.0 millimeters over a 9 day period (Figs. 6, 7). The ossicle was allowed to consolidate in the new position for 10 weeks and the device was removed (Fig. 8). The vertical dimension of the defect was completely repaired but a horizontal discrepancy remained. The defect was planned for onlay grafting to three dimensionally reconstruct the mandible. A large cortical bone graft was harvested from the mandibular ramus (Fig. 9). Figure 9 Approximately 50cc of intravenous blood was again drawn preoperatively and processed using the SMartPrep system. Platelet poor plasma was placed into the ramus donor site to aid in hemostasis. The ramus graft was contoured and adapted to the defect and fixated into place with screws (Fig. 10). A template fabricated from a diagnostic wax up confirmed the horizontal repair of the defect (Fig. 11). A APC+ membrane was made to place over the grafted site (Figs. 12, 13). Figure 10 Figure 11 Figure 13 Figure 12 The soft tissue over the graft healed well and the onlay bone graft was allowed to heal for four months (Fig. 14, 15). The ramus graft was well incorporated and revealed minimal resorption (Fig. 16). Figure 14 Figure 15 Figure 16 Three Steri-Oss Replace (Nobel Biocare, Yorba Linda, CA) implants were placed into the reconstructed mandible (Figs. 17, 18). Following a four month healing period the implants were restored with a provisional prosthesis and fabrication of the implant bridge was commenced (Fig. 19). Figure 17 Figure 18 Figure 19 Figure 20 DISCUSSION The use of APC+ has several indications in reconstructive surgery. The concentration of autologous growth factors has been shown to enhance the biologic events in bone and soft tissue healing. Although TGFB and PDGF are not osteoinductive they are capable of promoting bone regeneration and fracture healing. With distraction osteogenesis the normal process of fracture healing is interrupted by gradual traction on the soft bone callus. This tension causes the fibroblast-like cells within the callus to form collagen fibrils between the segments of bone. Osteoblasts located along the collagen fibers produce osteoid and become enveloped by the developing bone spicules. The autologous growth factors within the platelet concentrate enhance cellular recruitment and proliferation as well as rapid angiogenesis of the distraction gap and early development of the callus. In the second phase of reconstruction an APC+ biological membrane was used over the onlay bone graft to enhance the soft tissue healing in the compromised site. Studies have found that increasing the concentration of TFGB and PDGF in surgical incisions will accelerate healing and strengthen wound repair. Wound repair normally begins with clot formation and platelet degranulation which releases growth factors. The various cytokines and mediators found in the alpha granules of the platelets promote angiogenesis and collagen synthesis. Adding a prepared concentrate of the patients platelets to the bone grafted site can accelerate and improve soft tissue wound healing. Even with abundant scar tissue an excellent healing of the surgical wound was noted over the graft. The platelet-poor plasma (PPP) component from the processed blood sample was also used for graft donor site hemostasis. The fibrinogen within the PPP is activated by thrombin to polymerize into a fibrin clot. Postoperative control of bleeding appears to be similar to collagen hemostastic agents. CONCLUSION The use of APC+ improved the outcome in this challenging reconstructive case. In a compromised wound healing environment, from trauma and/or previous surgery, autologous growth factors optimize wound healing. These cytokines are especially important in the first weeks of distraction and or the early soft tissue healing over onlay bone grafts. The incorporation of APC+ and PPP for a distraction oseogenesis and ramus buckle onlay grafting has been observed by the author in 5 silimalr procedures to accelerate both soft tissue healing and bone maturation.