Minimizing the surgical approach in patients with spondylitis

Vancomycin-Loaded, Nanohydroxyapatite-Based Scaffold for Osteomyelitis Treatment: In Vivo Rabbit Toxicological Tests and In Vivo Efficacy Tests in a Sheep Model

The treatment for osteomyelitis consists of surgical debridement, filling of the dead space, soft tissue coverage, and intravenous administration of antimicrobial (AM) agents for long periods. Biomaterials for local delivery of AM agents, while providing controllable antibiotic release rates and simultaneously acting as a bone scaffold, may be a valuable alternative; thus, avoiding systemic AM side effects. V-HEPHAPC is a heparinized nanohydroxyapatite (nHA)/collagen biocomposite loaded with vancomycin that has been previously studied and tested in vitro. It enables a vancomycin-releasing profile with an intense initial burst, followed by a sustained release with concentrations above the Minimum Inhibitory Concentration (MIC) for MRSA. In vitro results have also shown that cellular viability is not compromised, suggesting that V-HEPHAPC granules may be a promising alternative device for the treatment of osteomyelitis. In the present study, V-HEPHAPC (HEPHAPC with vancomycin) granules were used as a vancomycin carrier to treat MRSA osteomyelitis. First, in vivo Good Laboratory Practice (GLP) toxicological tests were performed in a rabbit model, assuring that HEPHAPC and V-HEPHAPC have no relevant side effects. Second, V-HEPHAPC proved to be an efficient drug carrier and bone substitute to control MRSA infection and simultaneously reconstruct the bone cavity in a sheep model.

Tobramycin-impregnated calcium sulfate pellets for the treatment of chronic osteomyelitis in children and adolescents

The aim of this work was to evaluate the outcome and efficacy of treatment in a homogeneous group of skeletally immature patients with chronic osteomyelitis of the long bones managed by a combination of radical debridement and insertion of tobramycin-impregnated calcium sulfate pellets to fill the bone defect in a single-stage procedure. Between 2011 and 2016, 12 skeletally immature patients were treated surgically by the reported technique. Single-stage surgery using tobramycin-impregnated calcium sulfate pellets in association with systemic antibiotic therapy yields satisfactory outcomes in skeletally immature children presenting chronic osteomyelitis by reducing the risk of occurrence of comorbidities, hospital stays, and healthcare costs.

Single-Stage Surgery Using Calcium Sulfate Pellets in Association with Tumor Resection as Treatment for Intraosseous Hemangioma of the Radius Shaft in a 2-Year-Old Boy

Intraosseous hemangiomas are uncommon benign vascular tumors. Here the authors report a case of intraosseous hemangioma of the radial shaft in a 2-year-old boy, surgically treated by tumor mass resection and application of calcium sulfate pellets with no signs of relapse over a 2-year follow-up. Moreover, the lesion healed with new bone formation, and the last plain radiographs suggested homogenous normal trabecular bone density. The radius grew in length and remodeled to an almost normal shape. Clinically, elbow flexion-extension and forearm pronation and supination were within normal limits at the last follow-up visit. This report points to calcium sulfate pellets as a valid alternative to autologous bone grafting as void filler in large bone defects. Calcium sulfate pellets enable fast osteoinduction without interfering in follow-up imaging.

Clinical Application of Antimicrobial Bone Graft Substitute in Osteomyelitis Treatment: A Systematic Review of Different Bone Graft Substitutes Available in Clinical Treatment of Osteomyelitis

Osteomyelitis is a common occurrence in orthopaedic surgery, which is caused by different bacteria. Treatment of osteomyelitis patients aims to eradicate infection by debridement surgery and local and systemic antibiotic therapy. Local treatment increases success rates and can be performed with different antimicrobial bone graft substitutes. This review is performed to assess the level of evidence of synthetic bone graft substitutes in osteomyelitis treatment. According to the PRISMA statement for reporting systematic reviews, different types of clinical studies concerning treatment of osteomyelitis with bone graft substitutes are included. These studies are assessed on their methodological quality as level of evidence and bias and their clinical outcomes as eradication of infection. In the fifteen included studies, the levels of evidence were weak and in ten out of the fifteen studies there was a moderate to high risk of bias. However, first results of the eradication of infection in these studies showed promising results with their relatively high success rates and low complication rates. Due to the low levels of evidence and high risks of bias of the included studies, these results are inconclusive and no conclusions regarding the performed clinical studies of osteomyelitis treatment with antimicrobial bone graft substitutes can be drawn.

Chitosan coating to enhance the therapeutic efficacy of calcium sulfate-based antibiotic therapy in the treatment of chronic osteomyelitis

We demonstrate that coating calcium sulfate with deacetylated chitosan enhances the elution profile of daptomycin by prolonging the period during which high concentrations of antibiotic are released. Coatings reduced initial bolus release of daptomycin by a factor of 10 to approximately 1000 µg/ml, and levels remained above 100 µg/ml for up to 10 days. Chitosan-coated and uncoated calcium sulfate implants with and without 15% daptomycin were evaluated in an experimental model of staphylococcal osteomyelitis through bacteriology scores, radiology, histopathology, and Gram staining. Significant reduction in bacteriology scores was observed for implants containing daptomycin and coated with chitosan compared with all the other groups. We confirm that the use of chitosan-coated calcium sulfate beads for local antibiotic delivery can be correlated with an improved therapeutic outcome following surgical debridement in the treatment of chronic osteomyelitis.

Tissue engineering of bone: material and matrix considerations

When the normal physiologic reaction to fracture does not occur, such as in fracture nonunions or large-scale traumatic bone injury, surgical intervention is warranted. Autografts and allografts represent current strategies for surgical intervention and subsequent bone repair, but each possesses limitations, such as donor-site morbidity with the use of autograft and the risk of disease transmission with the use of allograft. Synthetic bone-graft substitutes, developed in an effort to overcome the inherent limitations of autograft and allograft, represent an alternative strategy. These synthetic graft substitutes, or matrices, are formed from a variety of materials, including natural and synthetic polymers, ceramics, and composites, that are designed to mimic the three-dimensional characteristics of autograft tissue while maintaining viable cell populations. Matrices also act as delivery vehicles for factors, antibiotics, and chemotherapeutic agents, depending on the nature of the injury to be repaired. This intersection of matrices, cells, and therapeutic molecules has collectively been termed tissue engineering. Depending on the specific application of the matrix, certain materials may be more or less well suited to the final structure; these include polymers, ceramics, and composites of the two. Each category is represented by matrices that can form either solid preformed structures or injectable forms that harden in situ. This article discusses the myriad design considerations that are relevant to successful bone repair with tissue-engineered matrices and provides an overview of several manufacturing techniques that allow for the actualization of critical design parameters.

Effectiveness of commercially-available antibiotic-impregnated implants

The aim of this study was to determine the effectiveness of antibiotic-impregnated implants in the prevention of bone infection. We used a model of contaminated fracture in goats to evaluate four treatment groups: no treatment, hand-made tobramycin-impregnated polymethylmethacrylate beads, commercially-available tobramycin-impregnated calcium sulphate pellets and commercially-available tobramycin-impregnated polymethylmethacrylate beads. Three weeks after intraosseous inoculation with streptomycin-resistant Staphylococcus aureus tissue cultures showed no evidence of infection in any of the antibiotic-treated groups. All of the cultures were positive in the untreated group. These results show that effective local antibiotic delivery can be obtained with both commercially-available products and with hand-made polymethylmethacrylate beads. The calcium sulphate pellets have the advantage of being bioabsorbable, thereby obviating the need for a second procedure to remove them.

Recent advances: Infections of the spine

The global increase of spinal infections is concomitant with the rise of its risk factors, including HIV/AIDS, diabetes mellitus, intravenous drug use, advanced age, and gunshot wounds to the spine. Because spinal infections have a wide span of presentation, early detection and differentiation are notoriously challenging. Current advances in laboratory and imaging techniques, such as polymerase chain reaction, fluorodeoxyglucose positron emission tomography, and 99mTc-ciprofloxacin scintigraphy, allow for better diagnostic rendering of the infection and its degree of spinal involvement. Less invasive surgical procedures and preventive surgical management have helped reduce spinal infection morbidities such as deformity and neurologic deficit. Although proper antibiotic regimen and correct surgical management are of vital importance to successful patient outcome, early detection remains the most critical factor.