One of the drawback's of bone transplantation from one part of the body to another is the creation of a secondary bone defect to treat the primary defect. Patrick H. Warnke from the Department of Oral and Maxillofacial Surgery at the University of Kiel in Germany, and colleagues treated a 56-year-old man who had had part of his jaw bone removed due to cancer. Rather than obtaining a graft from another part of the patient's body, such as the hip bone, the investigators used 3D computed tomography (CT) scanning and computer-aided design techniques to produce a replacement for the jaw-bone defect.
These data were used to create a titanium mesh cage that was filled with bone mineral blocks and 7 mg recombinant human bone morphogenetic protein 7 and 20 mL of the patient's bone marrow. The transplant was implanted into the muscle below the patient's right shoulder blade, the latissimus dorsi muscle. Seven weeks later, the new bone graft was transplanted as a free bone-muscle flap to repair the jaw-bone defect.
Bone remodelling and mineralisation inside the transplant were evident both before and after transplantation. CT provided radiological evidence of new bone formation. The patient regained the ability to chew. By the 4th week post transplantation he enjoyed his first dinner in nine years - bread and sausages. Before reconstruction he had only been able to eat soft food and soup.
Dr. Warnke commented: "To the best of our knowledge, this case provides evidence that heterotopic bone induction to form a mandibular replacement inside the latissimus dorsi muscle in a human being with a prefabrication technique is possible. The prefabrication technique described, and subsequent free-flap reconstruction of the mandible, allows for a lower operative burden and a better three-dimensional outcome than conventional reconstruction techniques. We suggest that our results represent a proof of principle. Many vital questions still remain unanswered. The exciting nature of the result achieved in this patient to date has prompted our group to extend this trial to include additional patients. For us to draw firm conclusions, an extended period of follow-up is necessary. We hope to present this patient's long-term outcome and those of future patients at a later date."
Stan Gronthos from the Hanson Institute in Adelaide, Australia, concluded in an accompanying commentary: "There is little doubt that scientists and clinicians alike will continue to challenge the benefits and merits of novel regenerative medical procedures for some time to come. Appropriate combinations of bio-engineering including biomaterials, growth factors, and stem cells, are essential for stable long-term function and integration of therapeutic implants. Meanwhile, as the debates continue, a patient who had previously lost his mandible through the result of a destructive tumour can now sit down to chew his first solid meals in nine years, courtesy of a new mandible-like structured implant, resulting in an improved quality of life for that individual."