Efficiency of 3D Implants with Bioactive Properties for Treatment of Extensive Bone Defects: Experimental Study

Background. The problem of replacing extensive bone defects remains relevant. The use of implant structures with bioactive properties can stimulate osteogenesis, which will improve the final treatment result.The aim of the study. In an in vivo experiment, to study the possibility of replacing an extensive defect in the bone diaphysis with a personal bioactive cellular 3D implant and evaluate the long-term results of its use.Materials and Methods. In an in vivo experiment, adult large mongrel dogs (n = 8) were modeled with an extensive segmental defect of the tibial diaphysis measuring 4 cm. The defect was replaced with a cellular bioactive 3D implant made of titanium alloy Ti6Al4V, manufactured using the additive technology. The diameter of the cells was 1.5 mm on average. The walls of the implant had pores of 100– 300 μm in size. The inner and outer surfaces were coated with a calcium phosphate layer formed by micro-arc oxidation. The primary fixation was provided with the Ilizarov apparatus. In the early postoperative period, antibiotic prophylaxis with broad-spectrum drugs was performed. Clinical, X-ray, histological and statistical methods were used to analyze the results. The main control points were considered: the end of external fixation with the Ilizarov apparatus, after 180 days and 1 year after the termination of external fixation.Results. During the experiment, the death of animals and complications were not observed. The spatial location of the implant was preserved. The formation of a strong bone-implantation block occurred 37.2±6.3 days after the operation. During this period, the external fixation apparatus was dismantled. Osseointegration was provided under conditions of sufficient primary mechanical stability, due to the cellular structure of the implant, the presence of pores on its walls, and the osteoinductive properties of the applied calcium phosphate coating. The achieved degree of osseointegration persisted in long-term periods (6 months and 1 year after the termination of external fixation). The osteoinductive properties of the calcium phosphate coating were confirmed by the expression of osteopontin cells at all stages of the experiment. Outflow of Ca and P from bone fragments was not observed. An elastic sheath was formed on the surface of the implant, similar in structure to the periosteum. The implant cells were filled with a well-vascularized bone substrate. In the projection of the intermediate zone, compact bone tissue was formed, and in the projection of the medullary canal — reticulofibrous bone marrow. This indicates the possibility of organotypic remodeling of bone structures inside the implant.Conclusion. The results of the study showed the effectiveness of using a bioactive cellular 3D implant to replace an extensive defect in the shaft of the bone. The architectonics and osteoinductive properties of the implant surface contributed to the formation of complete osseointegration in a short time, while maintaining the achieved result in long-term periods.

Propeller Dorsal Intercostal Artery Perforator Flap for an Extensive Defect on the Back Following Malignant Peripheral Nerve Sheath Tumor Resection: A Case Report

Posterior trunk defects have been a challenging anatomical area to cover in reconstructive surgery. The use of local myocutaneous flaps has been described extensively in the literature to cover these defects, but these techniques are associated with significant donor-site morbidity, including functional loss of muscle units. Freestyle perforator flaps enable local tissue recruitment with skin of a similar color and texture in diverse anatomic areas, but there is a shortage of case series on posterior trunk defects using propeller dorsal intercostal artery perforator (DICAP) flaps, particularly when the defects are extensive. In this report, the authors present a successful case of a DICAP propeller flap for an extensive defect on the upper back following a malignant peripheral nerve sheath tumor resection.

Shin both bones open fracture, complicated by purulent infection, complex surgical treatment

The article presents a clinical case of a successful multi-stage surgical treatment of a patient with shin both bones open fracture and an extensive defect of skin and soft tissues in the fracture zone, complicated by the development of purulent infection.