Treatment of chronic osteomyelitis with antibiotic-impregnated polymethyl methacrylate (PMMA) - the Cierny approach: is the second stage necessary?

Retention of Antibiotic Cement Delivery Implants in Orthopedic Infection Associated With United Fractures Does Not Increase Recurrence Risk

OBJECTIVES

To evaluate whether retention of antibiotic cement delivery devices after resolution of orthopaedic infection is associated with recurrence.

METHODS

DESIGN

Retrospective cohort.

SETTING

Academic medical center.

PATIENT SELECTION CRITERIA

Patients with a fracture definitively treated with internal fixation that went on to unite and develop a confirmed fracture-related infection or osteomyelitis after a remote fracture surgery and had implantation of antibiotic-impregnated cement for infection management.

OUTCOME MEASURES AND COMPARISONS

Patients were divided into whom the antibiotic implants were retained (Retained Cohort) and whom the antibiotic implants were removed (Removed Cohort). Outcome measures included clinical infection resolution, infection recurrence, time to resolution of infection signs, symptoms and laboratory values, reoperation and readmission rates, and need for soft tissue coverage (local flap vs. free tissue transfer) because of recurrence.

RESULTS

Of 98 patients treated for fracture-related infection in united fractures or osteomyelitis after a remote fracture surgery, 39 (39.8%) underwent implantation of antibiotic-impregnated cement delivery devices: 21 (21.4%) beads, 7 (7.1%) rods, and 11 (11.2%) blocks. Twenty patients (51.3%) comprised the Retained Cohort and 19 patients (48.7%) comprised the Removed Cohort. There were few differences in demographics ([American Society of Anesthesiology Score, P = 0.026] and [diabetes, P = 0.047]), infection location, and pathogenic profiles. The cohorts demonstrated no difference in eventual resolution of infection (100% in the Retained Cohort, 95% in the Removed Cohort, P = 0.487) and experienced similar time to clinical infection resolution, based on signs, symptoms, and laboratory values ( P = 0.360). There was no difference in incidence of subsequent infection recurrence after clinical infection resolution (1 recurrence Retained vs. 2 recurrences Removed, P = 0.605) for those considered "cured." Compared with the Retained Cohort, the Removed Cohort underwent more reoperations (0.40 vs. 1.84 reoperations, P < 0.001) and admissions after implantation ( P < 0.001).

CONCLUSIONS

Retention of antibiotic-impregnated cement delivery devices in patients with orthopaedic infection after fractured bones that have healed was not associated with infection recurrence. Additional surgical intervention with the sole purpose of removing antibiotic delivery devices may not be warranted.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Comparison of the Therapeutic Efficacy of Antibiotic-Loaded Polymeric Tissue Scaffold and Bone Cement in the Regeneration of Infected Bone Tissue

Background Local antibiotic applications have been used in chronic osteomyelitis and have been defined as an adjunctive treatment method. Biodegradable materials are also used for the same purpose by adding antibiotics. The fact that it does not require additional surgery to be removed is an important advantage. In this study, we intended to develop a new biodegradable drug-loaded polymeric scaffold with good antibiotic release and compare the microbiological results with antibiotic-impregnated bone cement. Methodology A tissue scaffold containing poly(2-hydroxyethyl methacrylate) (PHEMA) was prepared in our laboratory and loaded with ertapenem and daptomycin antibiotics. The surface morphology and pore geometries of drug-loaded and unloaded scaffolds were analyzed by a scanning electron microscope under vacuum. The dose-dependent antiproliferative effects of PHEMA scaffold, drug-loaded scaffold, cement, and drug-loaded cement on osteoblast cells were investigated. To evaluate drug release kinetics, the absorbance values of the scaffold loaded with ertapenem and daptomycin were measured with the spectrometer. For microbiological tests, ertapenem and daptomycin-impregnated cement and scaffold, as well as the control scaffold and cement samples, were investigated for their antibacterial activities on Staphylococcus aureus and Klebsiella pneumoniae strains using the disc diffusion method. These microorganisms are one of the most common microorganisms in osteomyelitis. Results The efficacy of antibiotic-impregnated scaffold and cement on both gram-negative and gram-positive microorganisms was investigated. The daptomycin zone diameter in S. aureus ATCC 29233 strain was 17 mm, whereas it was 24 mm for scaffold and 22 mm for cement. Scaffold was found to be more effective than cement against S. aureus strain. The K. pneumoniae ATCC BAA-2814 strain was found to be resistant to ertapenem, but the zone diameter was 21 mm for scaffold and 20 mm for cement. Ertapenem-loaded scaffold was found to be more effective than cement. It was found that the antimicrobial activity of the scaffold was higher than cement. When we evaluated the release profiles, for the daptomycin-loaded cement group, 98% of daptomycin was cumulatively released within 30 minutes, and for the daptomycin-loaded scaffold group, 100% of daptomycin was cumulatively released in six days. To compare ertapenem-loaded cement and scaffold, 98% of ertapenem was cumulatively released within 10 minutes in the cement group. For the scaffold group, 100% of ertapenem was cumulatively released in 17 days. We found that the scaffold released the antibiotic more slowly and for a longer duration. Therefore, it was thought that the scaffold would be more effective on biofilm and the treatment of osteomyelitis would be more successful. Conclusions The produced scaffold was compared with cement, and it was concluded that the scaffold had better release and antimicrobial efficacy. Scaffold is more advantageous than cement because it is bioeliminable. Thus, there is no need for a second surgical intervention with the likely prevention of mortality and morbidity. Because of all these features, the scaffold seems promising in the local treatment of osteomyelitis.

Antibiotic artificial bone implantation for the treatment of infection after internal fixation of tibial plateau fractures

OBJECTIVE

To explore the clinical effect of antibiotic artificial bone (Calcium phosphate) in the treatment of infection after internal fixation of tibial plateau fractures.

METHODS

We retrospectively reviewed the clinical data of 32 patients with infection after internal fixation of tibial plateau fractures treating from March 2010 to October 2021. There were 18 males and 14 females, aged from 23 to 70 (average 49.66 ± 10.49), 19 cases of the left side and 13 cases of the right side. Among them, 7 cases were open fractures with initial injury and 25 cases were closed fractures. On the basis of thorough debridement and implanting antibiotic artificial bone, the internal fixation of 18 patients were tried to be preserved and the internal fixation of 14 patients were removed completely. In order to provide effective fixation, 14 patients also received external fixation. Postoperative wound healing, infection control, Hospital for Special Surgery knee scores (HSS), related inflammatory indicators and bone healing time were recorded and followed up.

RESULTS

Thirty-two patients were followed up for 12 ~ 82 months (average 36.09 ± 19.47 months). The redness, swelling and pain of pin site occurred in 2 patients, which returned to normal after applying antibiotics and continuous dressing change. One patient retained the internal fixation during the first-stage operation. Redness and swelling of incision, subcutaneous undulation occurred after two months. In order to avoid the recurrence of infection, the internal fixation was removed completely and antibiotic artificial bone was filled again. The infection was controlled and fracture healed. Four patients' wounds could not be closed directly due to soft tissue defect and was covered with skin flap. After the first-stage operation, 12 patients received second-stage autologous iliac bone grafting due to residual bone defects and poor healing of the fracture end. The bone healing time was 4 ~ 16 months (average 7.31 ± 2.79 months). Inflammatory indicators including CRP, ESR, and WBC returned to normal levels within 2 ~ 10 weeks (average 4.97 ± 2.58 weeks). The HSS of all patients were 54 ~ 86 points (average 73.06 ± 8.44 points) at the last follow-up.

CONCLUSION

Implantation of antibiotic artificial bone, retention or removal of internal fixation according to infection and fracture healing, application of external fixation timely is an effective method to treat infection after internal fixation of tibial plateau fractures, which can control infection effectively and promote functional recovery.

Clinical Applications of Poly-Methyl-Methacrylate in Neurosurgery: The In Vivo Cranial Bone Reconstruction

Background: Biomaterials and biotechnology are becoming increasingly important fields in modern medicine. For cranial bone defects of various aetiologies, artificial materials, such as poly-methyl-methacrylate, are often used. We report our clinical experience with poly-methyl-methacrylate for a novel in vivo bone defect closure and artificial bone flap development in various neurosurgical operations. Methods: The experimental study included 12 patients at a single centre in 2018. They presented with cranial bone defects after various neurosurgical procedures, including tumour, traumatic brain injury and vascular pathologies. The patients underwent an in vivo bone reconstruction from poly-methyl-methacrylate, which was performed immediately after the tumour removal in the tumour group, whereas the trauma and vascular patients required a second surgery for cranial bone reconstruction due to the bone decompression. The artificial bone flap was modelled in vivo just before the skin closure. Clinical and surgical data were reviewed. Results: All patients had significant bony destruction or unusable bone flap. The tumour group included five patients with meningiomas destruction and the trauma group comprised four patients, all with severe traumatic brain injury. In the vascular group, there were three patients. The average modelling time for the artificial flap modelling was approximately 10 min. The convenient location of the bone defect enabled a relatively straightforward and fast reconstruction procedure. No deformations of flaps or other complications were encountered, except in one patient, who suffered a postoperative infection. Conclusions: Poly-methyl-methacrylate can be used as a suitable material to deliver good cranioplasty cosmesis. It offers an optimal dural covering and brain protection and allows fast intraoperative reconstruction with excellent cosmetic effect during the one-stage procedure. The observations of our study support the use of poly-methyl-methacrylate for the ad hoc reconstruction of cranial bone defects.

Use of Fluconazole-impregnated Beads to Treat Osteomyelitis Caused by Coccidioides in a Pigtailed Macaque (Macaca nemestrina)

A 3-y-old male pigtailed macaque (Macaca nemestrina) presented for swelling of the left distal forearm and decreased use of the arm. The monkey had been raised at an indoor-outdoor facility in Arizona and transferred to an indoor facility in Washington 2 mo prior to presentation. A preliminary diagnosis of fungal osteomyelitis of the radius was made based on radiographs and Coccidioides titers. In addition to systemic antifungal treatment, surgery was performed to debride the bony lesion and implant polymethylmethacrylate beads impregnanted with the anti-fungal fluconazole. Histologic examination of the debrided material confirmed the diagnosis of fungal osteomyelitis. The surgical procedure resulted in clinical improvement, as evidenced by weight gain and decreased Coccidioides titers. The beads were removed in a second surgery, and the bony lesion completely resolved. With continued systemic fluconazole treatment, the monkey remained healthy with no further evidence of osteomyelitis. Coccidioides is an emerging pathogen that causes significant morbidity and mortality in both humans and animals. Bone infections can be resistant to systemic treatment, and the implantation of fluconazoleimpregnated beads may offer a successful treatment strategy for fungal osteomyelitis.

PMMA-cement anterior column reconstruction in surgical treatment of spondylodiscitis

Introduction: and research question

This paper explains how antibiotic loaded cement can be used in surgical treatment of spondylodiscitis to reconstruct the anterior column of the spine.

Material and methods

35 consecutive surgical procedures performed for spondylodiscitis were collected over a 11-year period and charts were reviewed. Most infections were caused mainly by staphylococcus spp (n = 16), streptococcus spp (n = 8) and pseudomonas spp (n = 4). Most patients had long standing but unsuccessful antibiotic therapy (median 42 days). Other indications included instability, neurologic deficit, abscess, and patients were generally in very poor medical condition.

Results

Anterior debridement was followed by a partial cavity filling with surgical high viscosity PMMA cement in all cases. Cement was a high viscosity gentamycin loaded cement, that was placed in the cavity created by debridement under the direct eye control. In 25 cases, a part of the cavity was filled with freeze dried cancellous bone allograft rehydrated in rifampicin. Spine was further stabilized with an anterior plate in 15 cases, with short (+1/+1) posterior instrumentation in 5 cases, and a long (≥ +2/+2) posterior instrumentation in 11 cases. In four patients, spine was left un-instrumented. Immediate, unrestricted mobilization was always authorized after surgery. None of the patients were reoperated neither for mechanical failure nor for infection relapse.

Conclusion

This report supports the idea that surgical bone cement is an efficient gap filler when used through anterior approach. For small as well as for large defects, it can help to reconstruct the anterior column and locally control the infection in combination with additional stabilization and optimal intravenous and oral antibiotic treatment.

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Surgery is indicated in the treatment of some spondylodiscitis.

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PMMA cement has been tested to immediately fill the cavity left by debridement through anterior approach.

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Additional mechanical stability of the anterior column is valuable, in addition to classic instrumentation.

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As cement is loaded with gentamycin, it may participate to the local control of the infection and was surprisingly well tolerated on long term follow up.