Therapeutics and delivery vehicles for local treatment of osteomyelitis

Osteomyelitis, or the infection of the bone, presents a major complication in orthopedics and may lead to prolonged hospital visits, implant failure, and in more extreme cases, amputation of affected limbs. Typical treatment for this disease involves surgical debridement followed by long-term, systemic antibiotic administration, which contributes to the development of antibiotic-resistant bacteria and has limited ability to eradicate challenging biofilm-forming pathogens including Staphylococcus aureus—the most common cause of osteomyelitis. Local delivery of high doses of antibiotics via traditional bone cement can reduce systemic side effects of an antibiotic. Nonetheless, growing concerns over burst release (then subtherapeutic dose) of antibiotics, along with microbial colonization of the nondegradable cement biomaterial, further exacerbate antibiotic resistance and highlight the need to engineer alternative antimicrobial therapeutics and local delivery vehicles with increased efficacy against, in particular, biofilm-forming, antibiotic-resistant bacteria. Furthermore, limited guidance exists regarding both standardized formulation protocols and validated assays to predict efficacy of a therapeutic against multiple strains of bacteria. Ideally, antimicrobial strategies would be highly specific while exhibiting a broad spectrum of bactericidal activity. With a focus on S. aureus infection, this review addresses the efficacy of novel therapeutics and local delivery vehicles, as alternatives to the traditional antibiotic regimens. The aim of this review is to discuss these components with regards to long bone osteomyelitis and to encourage positive directions for future research efforts.     

Candida albicans osteomyelitis of the spine: progressive clinical and radiological features and surgical management in three cases

Candida albicans vertebral osteomyelitis is rare. Three cases are presented. Without antifungal treatment, they developed spinal collapse and neurological deterioration within 3–6 months from the onset of symptoms. There was a delay of 4.5 and 7.5 months between the onset of symptoms and surgery. All patients were managed with surgical debridement and reconstruction and 12-week fluconazole treatment. The neurological deficits resolved completely. The infection has not recurred clinically or radiologically at 5–6 years follow-up. Although rare, Candida should be suspected as a causative pathogen in cases of spinal osteomyelitis. Without treatment the disease is progressive. As soon as osteomyelitis is suspected, investigations with MRI and percutaneous biopsy should be performed followed by medical therapy. This may prevent the need for surgery. However, if vertebral collapse and spinal cord compression occurs, surgical debridement, fusion and stabilisation combined with antifungal medications can successfully eradicate the infection and resolve the neurological deficits.     

Management of chronic calcaneal osteomyelitis with pull-through abductor hallucis muscle flap -a report of three cases

Three patients who had chronic osteomyelitis of the calcaneus were treated with radical debridement of all involved soft tissue and bone and obliteration of dead space with a pull-through abductor hallucis brevis muscle flap. Two patients had calcaneal osteomyelitis without soft tissue loss resulting from previous comminuted calcaneal fractures while a third patient had a large soft tissue defect and calcaneal osteomyelitis resulting from a destructive infection. All of the patients had undergone several surgical procedures for treatment of the osteomyelitis with histories ranging 18 months to 30 months. Following treatment with the pull-through muscle flap there has been no recurrence over the longterm (>two years). We believe that radical removal of all contaminated tissue and immediately coverage with a muscle flap provides an effective single stage treatment of chronic calcaneal osteomyelitis.     

Understanding the microbiome of diabetic foot osteomyelitis: insights from molecular and microscopic approaches

Objectives

Rigorous visual evidence on whether or not biofilms are involved in diabetic foot osteomyelitis (DFO) is lacking. We employed a suite of molecular and microscopic approaches to investigate the microbiome, and phenotypic state of microorganisms involved in DFO.

Mandibular pseudocarcinomatous hyperplasia

AIMS: Three unusual cases of pseudocarcinomatous (pseudoepitheliomatous) hyperplasia (PH) affecting chronic osteomyelitic mandibular sequestra are reported to highlight the differences with the various squamous neoplasms which occur in that site. METHODS AND RESULTS: In two patients carrying a mandibular graft following the excision of an ameloblastoma, mucosal ulcers resulted in chronic osteomyelitis. In a third patient, an apical dental infection was associated with fistulated osteomyelitis. Histology of the three sequestra showed an intraosseous squamous proliferation. It was characterized by a peripheral involvement of medullary spaces, the more mature epithelial layer covering the bone trabeculae without intervening stroma, and the basal type epithelial layer surrounding a central fibrovascular core. There were no histological or cytological signs of malignancy. CONCLUSION: PH shows an inverted pattern when compared with the centro-medullary tumoural islands seen in the various oral or odontogenic squamous neoplasms which occur in the jaws. The lack of signs of malignancy distinguish PH from common squamous cell carcinomas. A short clinical course is an important feature in the distinction of PH from the well differentiated squamous cell carcinomas which may develop in fistulated chronic osteomyelitis.     

银杏注射液对化脓性骨髓炎单核细胞HLA-DR表达影响的研究

目的观察化脓性骨髓炎(Suppurativeosteomyelitis)免疫功能状态及应用中西医结合治疗的效果。方法采用免疫荧光技术连续监测28例化脓性骨髓炎患者的外周血单核细胞表面人类白细胞抗原DR位点(HLA-DR)抗原的表达,以及采用中药银杏注射液治疗后对其产生的影响。结果化脓性骨髓炎患者HLA-DR抗原的表达水平比健康人群低(P<0.05)。中药银杏治疗组患者比未用中药银杏治疗组患者的HLA-DR抗原的表达明显增强。结论化脓性骨髓炎机体产生大量炎性介质并释放,而单核细胞HLA-DR抗原的表达减少,正常免疫功能受到抑制,中药银杏有促进免疫功能恢复的作用。