519 Outcomes of Management with Ilizarov Frames in Bone Infection: An Observational Study

Aim The successful treatment and eradication of bone infection requires a multifaceted approach and may recur even after excision if resultant bone void is not managed effectively. This paper aims to review the clinical effectiveness of antibiotic-impregnated bone void filler and current empirical antibiotic guidelines. Method We report a retrospective study of 18 patients with chronic osteomyelitis following injury or surgery managed via Ilizarov Ring Fixator (IRF). All patients were managed by IRF stabilisation procedures with debridement, microbiological sampling, and bone void filling with antibiotic-impregnated biocomposite material, in addition to culture-specific systemic antimicrobial therapy. Results Patients were followed up for a mean of 15.9 months. Infection was eradicated in 94.1% of patients in a grossly comorbid demographic. Comorbidities associated with increased risk of osteomyelitis were noted in 72.2% of patients. Anaerobic bacteria were identified in culture for four (22.2%) of the 18 patients. Conclusions We detected a higher than suspected growth of anaerobes in our samples, suggesting the need for metronidazole in empirical antibiotic treatment. This study would suggest that the use of STIMULAN® may be preferable in this National Health Service from a cost-effect perspective, as our results are comparable to those using other bone void fillers.

Ceramic composite with gentamicin decreases persistent infection and increases bone formation in a rat model of debrided osteomyelitis

Introduction: Current methods of managing osteomyelitic voids after debridement are inadequate and result in significant morbidity to patients. Synthetic ceramic void fillers are appropriate for non-infected bone defects but serve as a nidus of re-infection in osteomyelitis after debridement. CERAMENT G (CG) is an injectable ceramic bone void filler which contains gentamicin and is currently being evaluated for use in osteomyelitic environments after debridement due to its theoretical ability to serve as a scaffold for healing while eliminating residual bacteria after debridement through the elution of antibiotics. The goal of this study was to evaluate (1) the rate of persistent infection and (2) new bone growth of a debrided osteomyelitic defect in a rat model which has been treated with either gentamicin-impregnated ceramic cement (CERAMENT G) or the same void filler without antibiotics (CERAMENT, CBVF). Methods: Osteomyelitis was generated in the proximal tibia of Sprague Dawley rats, subsequently debrided, and the defect filled with either (1) CG (n=20), (2) CBVF (n=20), or (3) nothing (n=20). Each group was euthanized after 6 weeks. Infection was detected through bacterial culture and histology. Bone growth was quantified using microCT. Results: Infection was not detected in defects treated with CG as compared with 35 % of defects (7/20) treated with CBVF and 50 % (10/20) of empty defects (p=0.001). Bone volume in the defect of CG-treated rats was greater than the CBVF (0.21 vs. 0.17, p=0.021) and empty groups (0.21 vs. 0.11, p<0.001) at 6 weeks after implantation. Conclusions: Ceramic void filler with gentamicin (CERAMENT G) decreased the rate of persistent infection and increased new bone growth as compared to the same void filler without antibiotics (CERAMENT) and an empty defect in a rat model of debrided osteomyelitis.

Improving Outcomes for Osteomyelitis After Partial Bone Resection: A Preliminary Report

Following partial bone resection for osteomyelitis, continued osteomyelitis in the remaining bone is common and problematic. Shortcomings in available surgical techniques to combat this also contribute to this problem. Presented are two case studies using a solution to this problem with a different type of bone void filler as a carrier vehicle for delivering antibiotics into the remaining infected bone to eradicate any residual bacteria in the remaining bone.

Reconstruction of anterior frontal wall and contours defects using bone substitute

Aim: The aim of this article is to report on the safety and long-term efficacy of Cerament® BoneVoid Filler bone substitute for repairing craniofacial bone defects. Post-traumatic cranioplasty is a complex and challenging procedure for all maxillo-craniofacial surgeons and neurosurgeons, especially when repairing large areas. The standard criterion for repairing small cranial defects is the use autogenous bone from the iliac crest or split calvarial grafts. Autogenous grafts may result in donor-site morbidity, increased surgical time, reabsorption, blood loss, and longer recovery time . Alloplastic materials used for bone repair, such as methyl methacrylate, hydroxyapatite, titanium, or porous polyethylene, are expected to have optimal properties, including easy adaptation, biocompatibility, ingrowth of new tissue, stability of shape, and low rate of reabsorption. A cranial implant should be easily shaped and positioned, allowing easy tissue growth. In very wide cranium defects the new technology is a custom made cranial implant constructed three-dimensionally with different types of materials. However, this procedure is very expensive with various infection rates depending on the kind of material used and on the chemicophysical composition of the implant. Methods: The authors report the case of a 50-year-old man with a severe deformity of the forehead-supra orbital area as a result of a previous complex fronto-facial trauma treated in an emergency Unit. Secondary correction and reconstruction of the residual deformities were performed by using Cerament® Bone Void Filler, an alloplastic biphasic material, composed of 40% hydroxyapatite, 60% calcium sulfate and the radio-contrast agent iohexol. The unique ratio of hydroxyapatite and calcium sulfate is designed to enable Cerament to resorb at the same rate that bone forms. Calcium sulfate acts as a resorbable carrier for hydroxyapatite which is highly osteoconductive, promoting bone ingrowth.It seems to be a promising bone graft substitute in the management of bony irregularities in the fronto-orbital area. Conclusion: The patient was first hospitalized as the result of a serious craniofacial trauma. One year after the first emergency cranio-orbital reconstructive operation, a marked deformity of the frontal region appeared with a “grid effect” due to the inadequate plate-bony fixation of the fractures applied during the first bony recomposition and because it was not as rigid as it should have been . A secondary surgery for deformity correction was performed. The hardware was totally removed and the bony deformity smoothed, reshaped, covered and filled using Cerament® Bone Void Filler, a biomaterial. The patient recovered with a satisfactory cranium-forehead shape, no complications, and complete disappearance of a frowning look of the fronto-orbital region. Recently, increased use of bone substitutes in the reconstruction of bone defects has been fuelled by donor site complications associated with autologous bone harvesting. Cerament® BoneVoid Filler is a biphasic and injectable bone substitute that has a highly compressive strength and the ability to promote cancellous bone healing

Electrospun, synthetic bone void filler promotes human MSC function and BMP-2 mediated spinal fusion

Introduction Synthetic bone grafts are often used to achieve a well-consolidated fusion mass in spinal fusion procedures. These bone grafts function as scaffolds, and ideally support cell function and facilitate protein binding. Objective The aim was to characterize an electrospun, synthetic bone void filler (Reb) for its bone morphogenetic protein (BMP)-2 release properties and support of human mesenchymal stem cell (hMSC) function in vitro, and its efficacy in promoting BMP-2-/bone marrow aspirate-(BMA)-mediated posterolateral spinal fusion (PLF) in vivo. Methods BMP-2 release kinetics from Reb versus standard absorbable collagen sponge (ACS) was determined. hMSC adhesion and proliferation on Reb was tested using cell counting, fluorescence microscopy and MTS. Cell osteogenic differentiation was quantified via cellular alkaline phosphatase (ALP) activity. For in vivo analysis, 18 Lewis rats were treated during PLF surgery with the following groups: (I) Reb + BMA, (II) Reb + BMA + BMP-2 and (III) BMA. A safe, minimally effective dose of BMP-2 was used. Fusion consolidation was followed for 3 months using radiography and micro-CT. After sacrifice, fusion rate and biomechanical stiffness was determined using manual palpation, biomechanical tests and histology. Results In vitro, BMP-2 release kinetics were similar between Reb versus ACS. MSC proliferation and differentiation were increased in the presence of Reb. At 3 months post-surgery, fusion rates were 29% (group I), 100% (group II), and 0% (group III). Biomechanical stiffness was higher in group II versus I. Micro-CT showed an increased bone volume and connectivity density in group II. Trabecular thickness was increased in group I versus II. H&E staining showed newly formed bone in group II only. Conclusions Reb possesses a high protein binding affinity and promotes hMSC function. Combination with BMA and minimal dose BMP-2 allowed for 100% bone fusion in vivo. This data suggests that a minimally effective dose of BMP-2 can be used when combined with Reb.