BackgroundImplant-related infections represent one of the most severe complications in orthopaedics. A fast-resorbable, antibacterial-loaded hydrogel may reduce or prevent bacterial colonization and biofilm formation of implanted biomaterials.Questions/purposesWe asked: (1) Is a fast-resorbable hydrogel able to deliver antibacterial compounds in vitro? (2) Can a hydrogel (alone or antibacterial-loaded) coating on implants reduce bacterial colonization? And (3) is intraoperative coating feasible and resistant to press-fit implant insertion?MethodsWe tested the ability of Disposable Antibacterial Coating (DAC) hydrogel (Novagenit Srl, Mezzolombardo, Italy) to deliver antibacterial agents using spectrophotometry and a microbiologic assay. Antibacterial and antibiofilm activity were determined by broth microdilution and a crystal violet assay, respectively. Coating resistance to press-fit insertion was tested in rabbit tibias and human femurs.ResultsComplete release of all tested antibacterial compounds was observed in less than 96 hours. Bactericidal and antibiofilm effect of DAC hydrogel in combination with various antibacterials was shown in vitro. Approximately 80% of the hydrogel coating was retrieved on the implant after press-fit insertion.ConclusionsImplant coating with an antibacterial-loaded hydrogel reduces bacterial colonization and biofilm formation in vitro.Clinical Relevance A fast-resorbable, antibacterial-loaded hydrogel coating may help prevent implant-related infections in orthopaedics. However, further validation in animal models and properly controlled human studies is required.

Background: Infection remains among the main reasons for joint prosthesis failure. Preclinical reports have suggested that antibacterial coatings of implants may prevent bacterial adhesion and biofilm formation. This study presents the results of the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC®) in patients undergoing hip or knee prosthesis.Methods: In this multicenter, randomized prospective study, a total of 380 patients, scheduled to undergo primary (n=270) or revision (n=110) total hip (N=298) or knee (N=82) joint replacement with a cementless or a hybrid implant, were randomly assigned, in six European orthopedic centers, to receive an implant either with the antibiotic-loaded DAC coating (treatment group) or without coating (control group). Pre- and postoperative assessment of clinical scores, wound healing, laboratory tests, and x-ray exams were performed at fixed time intervals.Results: Overall, 373 patients were available at a mean follow-up of 14.5 ± 5.5 months (range 6 to 24). On average, wound healing, laboratory and radiographic findings showed no significant difference between the two groups. Eleven early surgical site infections were observed in the control group and only one in the treatment group (6% vs. 0.6%; p=0.003). No local or systemic side effects related to the DAC hydrogel coating were observed, and no detectable interference with implant osteointegration was noted.Conclusions: The use of a fast-resorbable, antibiotic-loaded hydrogel implant coating can reduce the rate of early surgical site infections, without any detectable adverse events or side effects after hip or knee joint replacement with a cementless or hybrid implant.

BackgroundInfection is one of the main reasons for failure of orthopedic implants. Antibacterial coatings may prevent bacterial adhesion and biofilm formation, according to various preclinical studies. The aim of the present study is to report the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating (Defensive Antibacterial Coating, DAC®) to prevent surgical site infection, in patients undergoing internal osteosynthesis for closed fractures.Materials and methodsIn this multicenter randomized controlled prospective study, a total of 256 patients in five European orthopedic centers who were scheduled to receive osteosynthesis for a closed fracture, were randomly assigned to receive antibiotic-loaded DAC or to a control group (without coating). Pre- and postoperative assessment of laboratory tests, wound healing, clinical scores and X-rays were performed at fixed time intervals.ResultsOverall, 253 patients were available with a mean follow-up of 18.1 ± 4.5 months (range 12–30). On average, wound healing, clinical scores, laboratory tests and radiographic findings did not show any significant difference between the two groups. Six surgical site infections (4.6%) were observed in the control group compared to none in the treated group (P < 0.03). No local or systemic side-effects related to the DAC hydrogel product were observed and no detectable interference with bone healing was noted.ConclusionsThe use of a fast-resorbable antibiotic-loaded hydrogel implant coating provides a reduced rate of post-surgical site infections after internal osteosynthesis for closed fractures, without any detectable adverse event or side-effects.Level of evidence2.

Purpose Acute calcific tendinitis of the longus colli muscle (or retropharyngeal tendinitis) is an aseptic inflammatory process characterized by acute posterior neck pain, neck stiffness and dysphagia or odynophagia. Awareness of its existence is crucial in the differential diagnosis, because many other conditions, such as retropharyngeal abscess, meningitis or disc herniation, show similar clinical features. We present a case exhibiting an uncommon symptom (torticollis) and a brief literature review to emphasize the risk of misdiagnosis. Methods A 36-year-old woman presented with neck stiffness and torticollis accompanied by dysphagia and prevertebral space sensitivity on the second day. Results The diagnosis was established by computed tomography (CT), the gold standard for identifying the presence of prevertebral oedema and calcific deposition associated with retropharyngeal tendinitis. Treatment with NSAIDs and low doses of corticosteroids relieved the symptoms within 48 h. ConclusionsRetropharyngeal tendinitis is an underreported entity in the literature and orthopaedists should become aware of its existence. Misdiagnosis of this important mimicker may lead to unnecessary antibiotics administration and interventions in the retropharyngeal space.

Osteomyelitis is a serious infection predominantly caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Orthopaedic device-related infections are complex and require a careful combination of surgical intervention and antimicrobial therapy. Daptomycin, a cyclic lipopeptide, effectively penetrates soft tissue and bone and demonstrates rapid concentration-dependent bactericidal activity against Gram-positive pathogens. This retrospective, non-interventional study evaluated clinical outcomes in patients with osteomyelitis or orthopaedic device infections treated with daptomycin from the European Cubicin® Outcomes Registry and Experience (EU-CORESM) study. Patients were treated between January 2006 and April 2012, with follow-up to 2014. Clinical outcomes were assessed as success (cured or improved), failure or non-evaluable. Of 6,075 patients enrolled, 638 (median age, 63.5 years) had primary infections of osteomyelitis or orthopaedic device infections, 224 had non-prosthetic osteomyelitis, 208 had osteomyelitis related to a permanent or temporary prosthetic device, and 206 had orthopaedic device infections. The most commonly isolated pathogen was S. aureus (214 [49.1 %]; 24.8 % were MRSA). Overall, 455 (71.3 %) patients had received previous antibiotic therapy. Patients underwent surgical interventions, including tissue (225 [35.3 %]) and bone (196 [30.7 %]) debridement, as part of their treatment. Clinical success rates were 82.7 % and 81.7 % in S. aureus and coagulase-negative staphylococcal infections. Adverse events (AEs) and serious AEs assessed as possibly related to daptomycin were observed in 6.7 % and 1.9 % of patients, respectively. Daptomycin was discontinued by 5.5 % of patients due to AEs and 10 (1.6 %) deaths were reported. In conclusion, daptomycin was effective and safe in patients with osteomyelitis or orthopaedic device infections.

Introduction: Osteonecrosis (ON) is a multifactorial disease that leads to hip destruction. Lately, much focus has been at femoral head preservation with nonsurgical methods. In this study we examined the polymorphisms of IL-1α, IL-1R, IL-1RA, IL-4Rα, IL-1β, IL-12,γIFN, TGF-β, TNF-a, IL-2, IL-4, IL-6 and IL-10 genes for evaluation of their contribution in ON.Material and methods: DNA was extracted from 112 ON patients and 438 healthy donors. Analysis of the polymorphisms was completed using the PCR-SSP method. Statistical analysis was performed using theχ2test to compare the genotype and allelic frequency distribution.Results: The CT and GA genotypes of the IL-1α(-889) and TNF-a (-238) genes were found higher in the patients (51.8% and 10.8%, respectively) compared to the healthy donors (39.7% and 2.1%, respectively). In TGF-βcodon 25, the G to C polymorphism in the homozygous state was found in 1.8% of the patients and the C allele frequency was 8.9%, whereas the G allele frequency was 91.1%. Also, at the IL-10 (-1082) gene the GG genotype was 16.2% in the controls whereas in the patients was 7.2%.Conclusions: Based on the above, we showed that certain genotypes of the IL-1α, TGF-β, IL-10 and TNF-a genes could be related in the pathogenesis of a complicated disease, such as osteonecrosis. The presence of one of the above mentioned polymorphisms or the simultaneous carriage of more than one may further increase the risk for osteonecrosis, especially in those at high risk, such as patients receiving corticosteroids.

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We have evaluated the effect of the short-term administration of low therapeutic doses of modern COX-2 inhibitors on the healing of fractures. A total of 40 adult male New Zealand rabbits were divided into five groups. A mid-diaphyseal osteotomy of the right ulna was performed and either normal saline, prednisolone, indometacin, meloxicam or rofecoxib was administered for five days. Radiological, biomechanical and histomorphometric evaluation was performed at six weeks. In the group in which the highly selective anti-COX-2 agent, rofecoxib, was used the incidence of radiologically-incomplete union was similar to that in the control group. All the biomechanical parameters were statistically significantly lower in both the prednisolone and indometacin (p = 0.01) and in the meloxicam (p = 0.04) groups compared with the control group. Only the fracture load values were found to be statistically significantly lower (p = 0.05) in the rofecoxib group. Histomorphometric parameters were adversely affected in all groups with the specimens of the rofecoxib group showing the least negative effect. Our findings indicated that the short-term administration of low therapeutic doses of a highly selective COX-2 inhibitor had a minor negative effect on bone healing.