Treatment Of Infected Bone Defects Research Articles

Vancomycin-impregnated electrospun polycaprolactone (PCL) membrane for the treatment of infected bone defects: An animal study.

There is no consensus for the management of critical infected bone defects. The purpose of this study was to produce a vancomycin-impregnated electrospun polycaprolactone (PCL) membrane for the treatment of infected critical bone defects, and test it in a rabbit model. Electrospinning produced a resorbable PCL fiber membrane containing vancomycin approximately 1 mm in thickness, with a pore diameter of <10 μm. Femur defects were made in the limbs of 18 rabbits and infected with Staphylococcus aureus. The rabbits were divided into three groups according to treatment: (1) Experimental group: rabbit freeze-dried allogeneic bone graft and the vancomycin-PCL membrane. (2) Control group 1: bone graft. (3) Control group 2: vancomycin-PCL membrane only. Culture showed no difference in osteoclast activity between the three groups. Transwell testing showed that almost no fibroblasts passed through the membrane during the first 24 h, but some fibroblasts were able to pass it after 72 h. At 12 weeks after surgery, there was significantly less inflammatory cell infiltration in the experimental compared to the control groups. New bone formation and fracture bone callus were greater in the experimental group than control groups. We thus conclude the resorbable electrospun vancomycin-impregnated PCL membrane was effective at controlling bone infection, and in the regeneration of bone in a critical bone defect animal model.

Xenogenic bone with chitosan/norvancomycin sustained-release system for treatment of infectious bone defects in rabbits

Objective To investigate the effects of xenogenic bone with chitosan/norvancomycin sustained-release biomaterials in treating infectious bone defects in rabbits. Methods Xenogenic bone with chitosan/norvancomycin sustained-release biomaterials was made by electrospinning technique. Rabbit infectious bone defect models were made by Methicillin-resistant Staphylococcus aureus. A successful model was evaluated with the standard of more than three points in Norden score assessment. All models were divided into two groups by random number table method, with eight models in each. The control group was treated with surgical debridement, and the experimental group was implanted with bone particles of xenogenic bone with chitosan/norvancomycin sustained-release system after debridement. Postoperatively, general conditions, X-ray, histological results of HE staining, and bacteriological examination results of the rabbits were observed. Results X-ray showed significant bone defects, sequestration, periosteal reaction, and soft tissue swelling after one month of modeling, with Norden score of (3.84±0.52)points. The general conditions were good and the sinus tracts were healed in experimental group after two months of treatment. The control group demonstrated generally poor conditions with swollen sinus and purulent discharge. Two rabbits were died of sepsis. The pathological scores of tibial were (0.41±0.08)points in experimental group, and (3.27±0.26)points in control group by gross observation. The pathological score of experimental group was significantly lower than control group(P<0.05). The bone defects were basically repaired in experimental group. The longest diameter of bone defect in experimental group was (0.11±0.02)cm, significantly smaller than (0.48±0.06)cm in control group (P<0.05). There were no obvious signs of osteomyelitis and the bone defects were well repaired in experimental group. Periosteal reaction, soft tissue swelling, a substantial number of bone destruction, and sequestration were observed in control group. The Norden score was (1.32±0.23)points in experimental group, lower than (5.21±0.48)points in control group(P<0.05). HE staining showed a large amount of trabecular bone formation, bone cell formation, and fibrous hyperplasia in experimental group, with no obvious signs of infection. On the other hand, infiltration of inflammatory cells, necrotic tissue, and sequestration were observed in control group. The histological score was(0.61±0.10) points in experimental group, lower than (4.21±0.41) points in control group (P<0.05). The negative rate of bacterial culture in experimental group was 33%, lower than 100% in control group (P<0.05). Conclusion Xenogenic bone with chitosan/norvancomycin sustained-release biomaterials has excellent effect in infection clearance and bone defect reparation in treatment of infectious bone defects in rabbits. Key words: Osteomyelitis; Chitosan; Anti-bacterial agents; Drug delivery systems

Mesoporous silica nanoparticles/gelatin porous composite scaffolds with localized and sustained release of vancomycin for treatment of infected bone defects.

Treatment of infected bone defects still remains a formidable clinical challenge, the design of bone implants with the controlled release of antibiotics is now regarded as a powerful strategy for infection control and bone healing. In this study, we fabricated a composite scaffold based on vancomycin (Van) loaded mesoporous silica nanoparticles (Van@MSNs) and a gelatin matrix. The microscopic structure of the gelatin-based composite scaffolds was characterized as highly porous. By the addition of MSNs, an enhancement in the compression property of MSNs-incorporated composite scaffolds was observed. The Van could release from the Van@MSNs incorporated composite scaffold in a sustained-release manner with a minimal burst, and thus effectively inhibit the growth of Staphylococcus aureus in a subsequent in vitro antibacterial study. In addition, the drug-loaded composite scaffold showed no unfavorable effects on the proliferation and differentiation of bone mesenchymal stem cells (BMSCs), confirming good biocompatibility. Moreover, in vivo results demonstrated that the antibiotic-loaded composite scaffold could significantly reduce bacterial contamination while promoting bone healing. Thus, our results suggest that the fabricated Van@MSNs/Gelatin composite scaffold with a localized and sustained release of antibiotics is a promising biomaterial for treating infected bone defects.

Osteogenic and antibacterial properties of vancomycin-laden mesoporous bioglass/PLGA composite scaffolds for bone regeneration in infected bone defects

Chronic osteomyelitis and infected bone defects are substantial challenges faced by orthopaedic surgeons. In this study, vancomycin was loaded into mesoporous bioactive glass (MBG) to form a local antibiotic delivery system and then a bone tissue-engineering scaffold combining MBG and poly-(L-lactic-co-glycolic acid) (PLGA) was prepared by freeze-drying fabrication. In vitro degradation and water contact angle analysis suggested that the MBG-incorporated PLGA scaffold exhibited controlled degradability, stabilizing the pH of the surrounding environment and improved the hydrophilicity. Moreover, the presence of MBG provides a well-interconnected pore structure, to which human bone marrow-derived mesenchymal stem cells can attach, spread and proliferate, promoting upregulation of the expression of osteogenic markers. Thus, MBG/PLGA scaffolds exhibit better cytocompatibility and osteoblastic difierentiation properties compared with pure PLGA scaffolds. Vancomycin-loaded scaffolds have been found to yield sustained release that lasts for more than eight weeks in vitro. We tested the antibacterial performance of vancomycin-loaded scaffolds against Staphylococcus aureus, the most common bacteria isolated from infected bone. In vitro experiments demonstrated that loading vancomycin onto the scaffold promoted antibacterial activity and inhibited biofilm formation without deleterious effect on cytocompatibility. In conclusion, the novel inorganic-organic composites are considered potential materials for the treatment of infected bone defects.

Testing of a bioactive, moldable bone graft substitute in an infected, critically sized segmental defect model.

Large infected bone defects, often resulting from high energy traumas, are difficult to treat due to their variability in complexity and location. Standard treatment for infected bone defects begins with a protocol that includes a series of debridements in conjunction with an extended course of systemic antibiotics. Only after the infection has been eliminated will repair of the defect commence, typically with implantation of autologous bone. To address some of the shortcomings of the standard treatment methods, such as serial procedures, limited grafting material, and the need for a second surgical site for autologous bone, a sequential, dual drug-releasing, moldable, calcium sulfate-based bone graft substitute was developed previously. In the present studies, the effectiveness of the material for treating both the infection with vancomycin and bone defect with simvastatin was evaluated in vivo using a critically sized, infected segmental defect model in rat femurs. Although the infection was not fully eliminated, the local release of vancomycin increased survivorship of infected animals by 464% compared to nontreated controls. Infected animals receiving antimicrobial treatment showed comparable amounts of new bone formation within the defect site when compared to noninfected controls. Incorporating agents capable of disrupting established biofilms into bone graft substitutes may enhance effectiveness in treating a biofilm infection within a bone defect. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1878-1886, 2018.

Induced membrane technique combined with antibiotic calcium sulfate pellets in treating infected bone defect in lower extremity

Objective To evaluate the clinical effects of the Masquelet technique combined with antibiotic calcium sulfate pellets in treating infected bone defects. Methods From February 2014 to February 2016, 9 patients with infected bone defects were treated in our department, including 7 males and 2 females, with an average age of 37.0 years (range, 24-56 years). 6 cases were infected because of open fractures, 3 infected after internal fixation operation. All defects were located in the lower limb diaphysis and metaphysis (3 cases in femur, 6 cases in tibia). The length of the bone defects were 4-12 cm after debridement, all defects filled with PMMA loaded with Vancomycin, and fixed with external fixators. After 6-10 weeks, the bone cement spacers were taken out and the antibiotic calcium sulfate pellets were implanted into the membrane. A certain amount of autogenous cancellous bone granules would be mixed into the calcium sulfate pellets if the defect was larger than 6-8 cm. 5 cases remained fixed with external fixators, 3 cases replaced for plates, 1 case replaced for plaster external fixator. Regular X-ray follow-ups were taken and complications recorded as well. Evaluate the healing of bone defect and functional recovery of adjacent joints by Samantha X score system, visual analogue scale (VAS) and Paley method, respectively. Results The 9 cases were followed up for a mean duration of 9.3 months (range, 6-15 months). All bone defects healed after a mean time of 14 weeks (range, 10-24 weeks). The wound poor healing occurred in only 1 case in the first stage of surgery, and cured by dressing changes. No complications of the recurrence of infection and implant failure. At the last follow-up, the average Samantha X score was 4.9, the VAS score was 0 to 3 (average 1.5) for patients standing on crutches and all the bone defect healing graded excellent evaluated by Paley method, the functional recovery of the adjacent joints graded: excellent in 6 cases, good in 2 cases, and fair in 1 case (the excellent and good rate was 89%). Conclusion Masquelet technique combined with antibiotic calcium sulfate particles is effective in the treatment of infected bone defects. Key words: Lower extremity; Wounds and injuries; Infection; Anti-bacterial agents; Calcium sulfate

Controlled release of vancomycin from 3D porous graphene-based composites for dual-purpose treatment of infected bone defects

A vancomycin-loaded reduced graphene oxide/nano-hydroxyapatite (RGO–nHA) 3D porous composite for eradication of bone infection and facilitation of bone regeneration.

A solution to the vessel shortage during free vascularized fibular grafting for reconstructing infected bone defects of the femur: Bridging with vein transplantation

PurposeThe present study aimed to evaluate the feasibility and clinical efficacy of bridging vein transplantation to deal with the vessel shortage during free vascularized fibular grafting for reconstructing infected bone defects of the femur. MethodsTwelve patients (aged 15–58 years) with infected bone defects of the femur (between 6.0 and 18.0cm) were recruited in this study. Vacuum sealing drainage were applied after extensive debridement of the infected bone defects and irrigated with 0.9% sodium chloride solution for 1–2 weeks. After the drainage was clear and the focal infections were controlled, the free vascularized fibula was harvested for reconstructing the femoral bone defects. The vascularized fibula was grafted and fixated appropriately at the recipient site. The autogenous great saphenous vein was harvested, one end was anastomosed and bridged the vascular pedicles of the fibular grafts, and the other end anastomosed the artery and/or the vein in the recipient healthy site. ResultsMean length of vein transplantation with vascularized fibular graft was 10.2 cm (range 7–15cm). All patients had good radiological healing without recorded nonunion or malunion. No patient developed deep infection or implant failure. Primary bone healing was achieved in 10 patients; however, 2 grafted fibular formed pseudarthrosis with the recipient femoral and then healed after a secondary surgery. One patient suffered from graft stress fracture after bone healing and healed after external fixation. After the mean follow-up of 30 months (9–72 months), according to the Enneking scoring system, clinical outcomes were excellent in 7 patients, good in 4 and fair in one. The functional recovery rate of the lesion limb was 89.4%. ConclusionsFree vascularized fibular graft with vein transplantation bridged vascular pedicle can effectively repair the infected bone, improve blood supply to the bone defect site, and help control infection. It is a feasible and effective treatment for infected bone defects of the femur with poor soft tissue conditions, or blood supply vessel shortage.

A biodegradable antibiotic-eluting PLGA nanofiber-loaded deproteinized bone for treatment of infected rabbit bone defects.

We fabricated a biodegradable antibiotic-eluting poly(d,l)-lactide-co-glycolide nanofiber-loaded deproteinized bone (ANDB) scaffold that provided sustained delivery of vancomycin to repair methicillin-resistant Staphylococcus aureus bone defects. To fabricate the biodegradable ANDB, poly(d,l)-lactide-co-glycolide and vancomycin were first dissolved in 1,1,1,3,3,3-hexafluoro-2-propano. The solution was then electrospun to produce biodegradable antibiotic-eluting membranes that were deposited on the surface of bovine deproteinized cancellous bone. We used scanning electron microscopy to determine the properties of the scaffold. Both elution and high-performance liquid chromatography assays were used to evaluate the invitro vancomycin release rate from the ANDB scaffold. Three types of scaffolds were co-cultured with bacteria to confirm the invitro antibacterial activity. The infected bone defect rabbit model was induced by injecting 10(7) colony forming units of a methicillin-resistant Staphylococcus aureus strain into the radial defect of rabbits. Animals were then separated into treatment groups and implanted according to the following scheme: ANDB scaffold in group A, poly(d,l)-lactide-co-glycolide nanofiber-loaded deproteinized bone (NDB) scaffold with intravenous (i.v.) vancomycin in group B, and NDB scaffold alone in group C. Treatment efficacy was evaluated after eight weeks using radiological, microbiological, and histological examinations. Invitro results revealed that biodegradable ANDB scaffolds released concentrations of vancomycin that were greater than the minimum inhibitory concentration for more than four weeks. Bacterial inhibition tests also confirmed antibacterial efficacy lasted for approximately four weeks. Radiological and histological scores obtained invivo revealed significant differences between groups A, B and C. Importantly, group A had significantly lower bacterial load and better bone regeneration when compared to either group B or C. Collectively, these results show that our fabricated ANDB scaffolds possess: (1) effective bactericidal activity against methicillin-resistant Staphylococcus aureus, (2) the ability to promote site-specific bone regeneration, and (3) the potential for use in the treatment of infected bone defects.

Quick antiinfective spacer combined with Masquelet technique for treatment of infectious bone defects

Objective To investigate the efficacy of quick antiinfective spacer combined with Masquelet technique in the treatment of infectious bone defects. Methods From January 2006 to June 2013, we treated 52 patients with infectious bone defects. They were 46 men and 6 women, aged from 19 to 46 years (average, 31.3 years). They were treated by debridement and anti-infection therapy at the first stage when the individualized quick antiinfective spacers were prepared (a mixture of antibiotics and bone cement powder added by polymethyl methacrylate morphon). At the second stage, the bone defects were repaired using Masquelet technique before they were internally fixated. Results The 52 patients were followed up for an average time of 21 months (range, from 13 to 28 months). All the infectious bone defects were healed. X-ray examination showed that the bone mineral density at the bone grafting area increased significantly compared with pre-operation, suggesting granular bone resorption and new bone formation. All the fractures obtained bony union after 6 to 10 months (average, 7.5 months), without recurrence of infection or teratogenesis. Conclusions Quick antiinfective spacer can control local infection in the early period of bone defect by sustainable local release of effective antibiotics of high concentrations while it maintains limb length, increases the stability of fracture ends, and reduces contracture of bone and soft tissue. All these roles may create favorable conditions for late repair, reduce the infection rate and improve the efficacy of early management. Key words: Fractures, bone; Infection; Masquelet technique; Wound and injuries; Fracture fixation, internal

Repairing infected bone defects with compounds of autologous micromorselized bone and poly(D,L-lactide-co-glycolide) microspheres loaded with hydrochloric vancomycin

Objective To evaluate the effect of compounds of autologous micromorselized bone and [poly(D,L-lactide-co-glycolide),PLGA] microspheres loaded with hydrochloric vancomycin on repairing infected bone defects.Methods PLGA microspheres loaded with vancomycin were manufactured.Animal models of chronic osteomyelitis were created at the middle and upper segments of bilateral radii in 48 white rabbits.The rabbit models were randomized into 3 equal groups (16 in each).Bone defects were made one month later by topical debridement.In group A,tiny autogenous granular bone was implanted into the defects; in group B,autogenous bone microspheres loaded with vancomycin were implanted; in group C,compounds of autogenous tiny granular bone and vancomycin-loaded PLGA microspheres were implanted.The serum c-reaction protein (CRP) and erythrocyte sedimentation rate (ESR) were detected in each group at preoperation,1,3,7 days,2 and 4 weeks postoperation.Four rabbits were sacrificed each time at 2,4,8 and 12 weeks postoperation for gross observation,X-ray and histopathological examinations of the implant areas.Results At 3,7 days postoperation,the CRP level in group B was significantly lower than that in group A,but significantly higher than that in group C (P ＜ 0.05).At 1,3 days,2,4 weeks postoperation,the ESR in groups B and C was significantly lower than that in group A; at 7 days and 2 weeks postoperation,the ESR in group C was significantly lower than that in group B (P ＜ 0.05).At 2,4,8 weeks postoperation,groups B and C scored significantly better than group A in X-ray assessment (P ＜ 0.05).At 12 weeks postoperation,there was no significant difference in X-ray assessment between groups A,B and C (P ＞ 0.05).At 2,4,8,12 weeks postoperation,the histological scores for groups B and C were significantly higher than those for group A(P ＜ 0.05).Conclusion In treatment of infected bone defects in rabbits,compounds of autologous micromorselized bone and PLGA microspheres loaded with hydrochloric vancomycin are similar to autogenous bone microspheres loaded with vancomycin in therapeutic effect but better than tiny autogenous granular bone. Key words: Vancomycin; Polyglactin 910; Bone transplantation; Bone defects; Rabbits

Temporal separation in the release of bioactive molecules from a moldable calcium sulfate bone graft substitute.

Treatment of infected bone defects presents a considerable challenge due to the complications that occur from significant bone damage concomitant with contaminated tissue. These wounds are most often treated in a two-step sequence, where the infection is first eliminated before any attempt to repair the bone is undertaken. In order to combine these two treatment steps into one procedure, a moldable bone grafting material was developed to deliver drugs in a temporally separated manner. This was accomplished by a two-layered calcium sulfate composite consisting of a moldable outer shell containing antibiotic-loaded poly(lactic-co-glycolic acid) microspheres wrapped around a preformed core containing an osteogenic drug. The release of vancomycin from the shell portion began immediately and continued over the course of 6 weeks, while the release of simvastatin from the core was delayed for 12 days before being released over the next 4 weeks. Bioactivity of vancomycin was shown in modified Kirby-Bauer experiments in which whole samples inhibited Staphylococcus aureus (S. aureus) growth for 2 weeks. This two-layered system is capable of delivering antibiotics locally for clinically relevant periods of time and delaying the release of osteogenic drugs to mimic a two-step procedure that has potential for treating infected bone defects.

Local delivery systems for the treatment of infected bone defects

The treatments of infected bone defects are still a major clinical problem.In recent years,local delivery systems applied as anti-infection and bone repair material become a hot research topic.In this review,we discuss various influence factors such as osteoinductive growth factors,antibiotics,cartier material,extended release methods.We also introduce the recent progress in the development of local delivery system for the treatment of infected bone defects. Key words: Infected bone defects; Local delivery systems; Artificial bone material

In Vitro and In Vivo Analysis of a Biodegradable Poly(lactide-co-glycolide) Copolymer Capsule and Collagen Composite System for Antibiotics and Bone Cells Delivery

The authors investigated poly(lactide-co-glycolide) (PLGA) capsule and collagen composite system for antibiotics and bone cells delivery to treat infected bone defects. Poly(lactide-co-glycolide) was mixed with vancomycin and hot compressing molded to form an antibiotic capsule. Rabbit mesenchymal stem cells (MSCs) were entrapped in collagen gel phase and dispersed throughout the void volume of capsule. In vitro study, the composite systems were cultured in complete or osteogenic medium for 21 days. The profiles of vancomycin released from the systems were evaluated using the high-performance liquid chromatography method. Relative activity of vancomycin against Staphylococcus aureus was determined by an antibiotic disk diffusion method. The expression of osteogenic gene was determined by reverse-transcription polymerase chain reaction. The alkaline phosphatase activity and calcium level of the MSCs were assessed. Analytical results demonstrated that the concentrations of vancomycin eluted from the composite system were above the minimal inhibitory concentration for 21 days. Sample inhibition zone was 10 to 24 mm, and the relative activity was 17.6% to 100%. mRNA of Cbfa1 and osteocalcin were detected, and increased alkaline phosphatase activity and calcium levels were noted. In in vivo investigation, the PKH 26-labeled MSCs and composite systems were implanted in the distal femoral cavities of four rabbits. The local concentration of vancomycin was above the minimal inhibitory concentration for 56 days. Sample inhibition zone was 9 mm to 24 mm, and the relative activity was 11.8% to 100%. Implanted PKH 26-labeled MSCs were identified in the newly formed bony trabeculae in specimens at 2 and 4 months after implantation. The results offer a potential approach to meet clinical requirements in the treatment of infected bone defects.

Sustained release of vancomycin from polyurethane scaffolds inhibits infection of bone wounds in a rat femoral segmental defect model

Infection is a common complication in open fractures that compromises the healing of bone and can result in loss of limb or life. Currently, the clinical standard of care for treating contaminated open fractures comprises a staged approach, wherein the wound is first treated with non-biodegradable antibiotic-laden poly(methyl methacrylate) (PMMA) beads to control the infection followed by bone grafting. Considering that tissue regeneration is associated with new blood vessel formation, which takes up to 6 weeks in segmental defects, a biodegradable bone graft with sustained release of an antibiotic is desired to prevent the implant from becoming infected, thus allowing the processes of both vascularization and new bone formation to occur unimpeded. In the present study, we utilized biodegradable porous polyurethane (PUR) scaffolds as the delivery vehicle for vancomycin. Hydrophobic vancomycin free base (V-FB) was obtained by precipitating the hydrophilic vancomycin hydrochloride (V-HCl) at pH 8. The decreased solubility of V-FB resulted in an extended vancomycin release profile in vitro, as evidenced by the fact that active vancomycin was released for up to 8 weeks at concentrations well above both the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Using PUR prepared from lysine triisocyanate (LTI) (PUR(LTI)), the extended in vitro release profile observed for V-FB translated to improved infection control in vivo compared to V-HCl in a contaminated critical-sized fat femoral segmental defect. The performance of PUR(LTI)/V-FB was comparable to PMMA/V-HCl beads in vivo. However, compared with PMMA, PUR is a biodegradable system which does not require the extra surgical removal step in clinical use. These results suggest that PUR scaffolds incorporating V-FB could be a potential clinical therapy for treatment of infected bone defects.

Manufacture of solvent‐free polylactic‐glycolic acid (PLGA) scaffolds for tissue engineering

AbstractConventional methods for fabricating polymeric scaffolds often use organic solvents which might be harmful to cells or tissues. The purpose of this report was to develop a solvent‐free method for the fabrication of three‐dimensional scaffolds for tissue engineering. To manufacture a scaffold, polylactide‐polyglycolide (PLGA) copolymers were premixed with sodium chloride particulates. The mixture was then compression molded and sintered to form a cylinder. After sintering, the cylinder was submerged in water for 48 h to leach out the particulates. The scaffold, with approximately 2 × 107 mesenchymal stem cells (MSCs) of the New Zealand rabbit, was then cultured in an osteogenic culture medium for 14 days. The alkaline phosphatase activity, calcium level, and the mineral deposition of cultured cells in the PLGA scaffolds were determined. The results showed that an increase of alkaline phosphatase activity and calcium levels, as well as abundant mineral deposition, was observed in the cultured mesenchymal stem cells. In addition, scaffolds with pore sizes of 88–125 µm showed the most number of cells during the period of culture. Developing solvent‐free biodegradable scaffolds for bone cells may provide a potential method for the treatment of infected bone defects. Copyright © 2008 Curtin University of Technology and John Wiley &amp; Sons, Ltd.

A biodegradable delivery system for antibiotics and recombinant human bone morphogenetic protein‐2: A potential treatment for infected bone defects

To produce an osteogenic and bacteriocidal biomaterial for the treatment of infected nonunions or bone defects, a synthetic degradable block copolymer of poly-D,L-lactic acid segments with randomly inserted p-dioxanone and polyethylene glycol (PLA-DX-PEG) segments was mixed with recombinant human BMP-2 (rhBMP-2) and antibiotics at high concentration. We then examined the in vitro elution profile of an antibiotic (teicoplanin) from the polymer, the effects of antibiotics on the bone-inducing capacity of rhBMP-2 or on ectopic new bone formation induced by the rhBMP, and the ability of the polymer to repair bone in a rat cranial defect model. Approximately 40% of teicoplanin was released within the first 24 h, with the remaining amount released steadily over 21 days with no loss of antibacterial activity. The polymer had disappeared by degradation in the phosphate buffered saline (pH 7.4) at the end of the incubation period. The in vivo performance of pellets with antibiotics and rhBMP-2 revealed no significant change in bone yield within the ossicles after 3 weeks. Also, antibiotics had no inhibitory effect on the ability of rhBMP2 to repair cranial defects. Indeed, when the defect was filled by a polymer disc loaded with rhBMP-2 with or without teicoplanin, the defect was repaired by new bone, and normal anatomy was restored within 6 weeks. In conclusion, the PLA/DX/PEG polymer appears to work as effectively for antibiotics as it does for rhBMP-2. Additionally, the biological activity of rhBMP-2 was retained irrespective of the presence of antibiotics.

One‐stage treatment of infected bone defects of the tibia with skin loss by free vascularized osteocutaneous grafts

Twenty-six patients who had an infected nonunion or segmental defect of the tibia with skin loss were treated in one stage with debridement and a free vascularized osteocutaneous fibula or iliac graft. Successful control of infection, closure of skin defects, and incorporation of bone union were achieved in all patients except one. In an average follow-up of 39 months, no recurrence of infection was seen. There were four stress fractures of the grafted fibula; these healed within 2 months with cast immobilization. Graft hypertrophy was common in the fibula grafts, but it took 1 1/2 years for hypertrophy of the graft to be strong enough to remove external supports without stress fracture or an additional cancellous bone graft. The use of a one-stage free vascularized osteocutaneous graft for the management of infected bone defects of the tibia with skin loss is effective because extensive debridement can remove all devitalized and infected tissue and can increase vascularity in the region of infection and osseous defect to enhance antibiotic delivery.

Surgical treatment of infected bone defects

International Abstracts of Plastic and Recontructive Surgery: Neoplasms: Surgical Management: Techniques and Instruments: PDF Only

Treatment of Infected Bone Defects with Cancellous Bone-Chip Grafts

Treatment of Infected Bone Defects with Cancellous Bone-Chip Grafts