Infektionen in der Orthopädie und Traumatologie: Pathogenese und Therapie

Calculated parenteral initial treatment of bacterial infections: Bone and joint infections

This is the 10^th chapter of the guideline “Calculated initial parenteral treatment of bacterial infections in adults – update 2018” in the 2^nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience.

This chapter deals with bacterial Infections of bones, joints and prosthetic joints. One of the most pressing points is that after an initial empirical therapy a targeted antimicrobial which penetrates well to the point of infection and is tolerated well over the usually long duration of the therapy is chosen.

[Musculoskeletal infections in the era of multiresistant pathogens]

The burden of musculoskeletal infections is permanently growing. A probable explanation for this development could be the increasing number of elderly people undergoing extensive surgery using implants and prosthetic devices while having more significant comorbidities (e.g. cardiovascular, metabolic and malignant). However, a relative reduction of acute (hematogenous) osteomyelitis compared to the occurrence of much more complex situations, such as diabetic foot syndrome or chronic osteitis and prosthetic implant infections is being observed. This poses new challenges for the clinician in managing these patients. Furthermore, there is the evolving threat of antimicrobial resistance as well as the increasing amount of infections with Gram-negative pathogens. Several aspects have to be considered for successful management of musculoskeletal infections: the site of infection and feasibility of local surgical treatment, the effectiveness of antimicrobial treatment, the inclusion of comorbidities and their specific treatment in an advanced therapeutic concept as well as the interdisciplinary approach led by surgeons and infectious disease specialists.

Bacillus species infective arthritis after knee arthroscopy

BACKGROUND

Bacillus species infection of the joints is a very rare occurrence, with sporadic reports in the medical literature.

CASE REPORT

A 67-year-old woman with osteoarthritis developed infection in the knee joint after arthroscopy. Percutaneous needle aspiration of articular fluid performed post-operatively showed a positive culture for Bacillus species. The diagnosis of septic arthritis was, however, not confirmed as the results were considered contamination. Failure of treatment with beta-lactam antibiotics on two occasions and successful cure of infective arthritis by long-term administration of a fluoroquinolone confirmed iatrogenic clinical joint infection with Bacillus species.

CONCLUSION

Any clinically suspected joint infection must be treated as septic arthritis until proved otherwise.

Clinical significance of the pharmacokinetic and pharmacodynamic characteristics of fosfomycin for the treatment of patients with systemic infections

The advancing antimicrobial drug resistance in common bacterial pathogens, along with the relative shortage of new antibacterial agents, call for the re-evaluation of available therapeutic options. Fosfomycin is an established treatment option for uncomplicated urinary tract infections. Here we review and evaluate the main pharmacokinetic and pharmacodynamic parameters of intravenously administered fosfomycin with regard to its use for systemic infections. Fosfomycin is a relatively small, hydrophilic agent with almost negligible serum protein binding. It is excreted unchanged in urine, achieving high concentrations for a prolonged period. Fosfomycin has good distribution into tissues, achieving clinically relevant concentrations in sites such as serum, soft tissue, lungs, bone, cerebrospinal fluid and heart valves. Fosfomycin has shown antimicrobial activity against biofilms, particularly in combination with fluoroquinolones. It also exerts immunomodulatory effects, mainly on lymphocyte and neutrophil function. Potentially useful properties of fosfomycin regarding its use in combination regimens include reduction in the expression of certain penicillin-binding proteins and attenuation of nephrotoxicity caused by several antimicrobial agents. In conclusion, the pharmacokinetic and pharmacodynamic properties of fosfomycin do not preclude its use for various types of systemic infections and suggest further research on relevant clinical applications of this agent.

Septic arthritis as a severe complication of elective arthroscopy:clinical management strategies

Infection of a peripheral joint following arthroscopic surgery presents with an incidence of approximately 0.42% an extremely rare entity. However, septic arthritis is a serious situation possibly leading to an irreparable joint damage. Especially at delayed diagnosis patients' safety can be endangered severely. Only few precise statements regarding diagnosis and therapy have been published so far. Besides an accurate analysis of the patient's anamnesis and the assessment of the C-reactive protein especially arthrocentesis is required for diagnostic workup. For early stage infections arthroscopic therapy is proven to be of value. In addition a calculated and consecutive germ-adjusted antibiotic therapy is essential. In case of persisting signs of infection the indication for re-arthroscopy or conversion to open revision has to be stated in time. The number of necessary revisions is dependent on the initial stage of infection. For pain therapy postoperative immobilization of the affected joint is occasionally essential, if otherwise possibly early mobilization of the joint should be performed.

[Infection after arthroscopy]

Infection of a peripheral joint following arthroscopic surgery is extremely rare, with an incidence of up to 0.42%. However, the consequences of delayed diagnosis can be dramatic. Besides taking an exact patient history, C-reactive protein determination and, especially, diagnostic arthrocentesis are required. For early-stage infections, arthroscopic therapy has been proven valuable. In addition, calculated and antibiogram-adjusted antibiotic therapy is essential. In the case of persisting signs of infection, re-arthroscopy should be considered quickly, with indications broad. The number of necessary revisions depends on the initial stage of infection. Postoperative immobilisation of the affected joint is occasionally essential for treating pain; otherwise, early mobilisation of the joint should be performed.