[Bone substitute materials as local drug carriers : Current status of substitutes of various origins]. / Knochenersatzwerkstoffe als lokale Wirkstoffträger : Aktueller Stand bei Ersatzstoffen verschiedenen Ursprungs.

BACKGROUND: Autologous bone grafts (autografts) are used in surgery for defect filling and impaction grafting during hip socket and femur reconstruction. Because of their superior osteoinductive capacity, autografts are considered the "gold standard" for these treatments. However, because of a better cost-benefit ratio, allografts are also often used. In the case of limited donor availability for autologous or allogenic bone grafts, bone substitute materials (BSMs) are a reasonable alternative or supplement. BSM are based on or combine different substances. Growth factors of the bone morphogenetic protein family BMP are recombinant proteins that specifically induce the growth of bone and cartilage tissue. CHARACTERISTICS: One advantage of BSM is the option to combine them with several anti-infective agents. The choice of the anti-infective substance should not only be based on the antimicrobial efficacy, but should also take into account possible dose-dependent cellular and pharmacological side effects at the implantation site. Thus, microbiologists, pharmacists and surgeons should decide together which combination is the most appropriate. COMBINATION PRODUCTS: BSM with active agent additives are considered combination products that are characterized by a main effect (bone replacement function) and a secondary effect (prophylaxis of bacterial recolonization of BSM). Both functions must be thoroughly (clinically) evidenced in the course of the registration process as a class III medical device. Drug authorities evaluate the active agents, their function and corresponding indication. Currently, only a few combination products are available on the market. As a consequence of the only limited availability of such commercial combination products, surgeons in clinical practice often manually add the active agent to BSM in the theatre prior to implantation. However, such a customized addition of antibiotics places the surgeon in a situation of a manufacturer where he assumes liability for the product.

Clinical use and safety of a novel gentamicin-releasing resorbable bone graft substitute in the treatment of osteomyelitis/osteitis.

OBJECTIVE: A clinical investigation into a new bone void filler is giving first data on systemic and local exposure to the anti-infective substance after implantation. METHOD: A total of 20 patients with post-traumatic/post-operative bone infections were enrolled in this open-label, prospective study. After radical surgical debridement, the bone cavity was filled with this material. The 21-day hospitalisation phase included determination of gentamicin concentrations in plasma, urine and wound exudate, assessment of wound healing, infection parameters, implant resorption, laboratory parameters, and adverse event monitoring. The follow-up period was six months. RESULTS: Systemic exposure to gentamicin after implantation was very low as local gentamicin concentrations were measured in wound exudate after six to ten hours. There were no signs of infectious complication throughout the clinical phase. Four patients had recurrent infections several weeks to months after implantation. The outcome was deemed successful by remission of infection in 16 (80%) of these problematic long-term treated patients. Safety laboratory measurements did not indicate nephrotoxic or hepatotoxic effects. CONCLUSIONS: Local application of calcium sulphate/carbonate bone void filler comprising gentamicin revealed sufficient active local levels of the antibiotic by simultaneous significant low systemic exposure in patients with mostly chronic osteomyelitis/osteitis. The material was safe and well tolerated. Cite this article: Bone Joint Res 2014;3:223-9.

The use of a Type-I lyophilisate collagen as an osteoinductive factor in pseudarthroses of the forearm.

The purpose of this study was to assess the use of a novel bone void filler consisting of Type I collagen and various growth factors (VEGF, TGFß-1, TGFß-2, IGF-1, BMP-2, BMP-3, and BMP-7) and surgical fixation to treat diaphyseal forearm pseudarthroses. Eleven patients underwent an osteosynthesis procedure for isolated pseudarthrosis fractures of the forearm (six radial and five ulnar diaphysis). The mean duration between the initial failed surgical fixation and re-operation was 38 weeks. Radiographic signs of fracture healing after the application of the bone void filler were noted at a mean of 5 weeks, and complete fracture consolidation was achieved at a mean of 6 weeks. All patients demonstrated improved range of motion and grip strength. Additionally, all patients were pain-free by 6 weeks. The combination of a novel bovine bone-derived bone void filler and stable internal fixation led to union and rapid healing of forearm pseudarthroses.

[Perioperative antibiotic prophylaxis in orthodontic bone operations of the facial skull]. / Perioperative Antibiotikaprophylaxe bei skelettverlagernden Operationen des Gesichtsschädels.

Intraoral orthognathic surgical procedures are clean-contaminated operations because of the facultative pathogenic flora of the oral cavity. Without antibiotic prophylaxis in this kind of operation a postoperative wound infection can be expected in 20-31% of cases. Therefore, a retrospective analysis of the clinical course of 545 patients with various dentofacial deformities was performed to evaluate the importance of perioperative antibiotic prophylaxis. The total rate of wound infections was 2.8% and lower than rates published in other comparable studies without antibiotic prophylaxis. The rate of wound infection after single mandibular osteotomy (4.1%) was significantly higher than the analogous amount after single maxillary osteotomy (0.8%) because of the mechanical strain of the surgical wound in the region of the mandibular angle and because of the high retention of food particles and other decay products in this area. The recognized rise in the wound infection rate by increasing the length of operation demonstrates that the extent of bacterial contamination of the surgical wound depends on the dimension and duration of surgery. Bacterial flora caused the noticed wound infections in 61.5% of cases aerobic-anaerobic mixed infections, which is in accordance with the results of similar publications. With increasing length of antibiotic prophylaxis, an increase in the incidence of antibiotic-associated side effects and in the wound infection rate could be observed. Therefore, an antibiotic prophylaxis which exceeds 3 days does not seem to be useful. In this study, in which cephalosporins were mostly used, the total rate of antibiotic-associated side effects (4.6%) was lower than analogous amounts of other groups of antibiotics. The analysis demonstrates that a short-term prophylaxis with broad-spectrum cephalosporins such as cefatoxime of 48 h is very effective and useful.