[Bone substitutes - basic principles and clinical applications]

[Reconstruction of posttraumatic deformities and defects]

The reconstruction of posttraumatic defects of bone and soft tissue, as well as residual deformities of the bone is often a lengthy and complicated procedure. Multiple surgical interventions are necessary to reconstruct the affected extremity and restore its functionality. To achieve an optimal result it often takes months or years and requires great patience and compliance of the patient. This treatment should be carried out in centers with the appropriate instrumental and human resources. Since the pathologies are often complex with bony deformities or loss of bone, as well as infections and soft tissue defects, the treatment should be carried out by very experienced surgeons to successfully manage these complex reconstructions. This often requires interdisciplinary cooperation, especially with experienced plastic surgeons. A soft tissue reconstruction for better blood circulation in the exposed bony structures, as well as the bony defects themselves, can be reconstructed at the same time.

World's First Clinical Case of Gene-Activated Bone Substitute Application

Treatment of patients with large bone defects is a complex clinical problem. We have initiated the first clinical study of a gene-activated bone substitute composed of the collagen-hydroxyapatite scaffold and plasmid DNA encoding vascular endothelial growth factor. The first patient with two nonunions of previously reconstructed mandible was enrolled into the study. Scar tissues were excised; bone defects (5–14 mm) between the mandibular fragments and nonvascularized rib-bone autograft were filled in with the gene-activated bone substitute. No adverse events were observed during 12 months of follow-up. In 3 months, the average density of newly formed tissues within the implantation zone was 402.21 ± 84.40 and 447.68 ± 106.75 HU in the frontal and distal regions, respectively, which correlated with the density of spongy bone. Complete distal bone defect repair with vestibular and lingual cortical plates formation was observed in 6 and 12 months after surgery; thereby the posterior nonunion was successfully eliminated. However, there was partial resorption of the proximal edge of the autograft entailed to relapse of the anterior nonunion. Thus, the first clinical data on the safety and efficacy of the gene-activated bone substitute were obtained. Given a high complexity of the clinical situation the treatment, results might be considered as promising. NCT02293031.