[Imaging diagnostics of osteitis, osteomyelitis and joint infections]

[Native joint infections]

Joint infections are a great challenge for the treating physicians. Infection of a native joint can result in the rapid destruction of the joint if treatment is inadequate or delayed and is associated with severe life-threatening diseases, such as sepsis. This article presents a detailed overview of the treatment of joint infections of native joints with a focus on the diagnostic approach and treatment decisions. Infections in native joints are caused either endogenously by hematogenic spreading or are caused by exogenous factors. A relevant proportion of joint infections in native joints occur in connection with iatrogenic measures, such as operations, synovial punctures and joint infiltrations. Fundamentally, acute infections represent an orthopedic surgical emergency, which is associated with the necessity for immediate operative measures. The best possible success can only be achieved by an interaction between early diagnosis, an adequate surgical approach and a tailor-made anti-infectious treatment. This is also the case with periprosthetic infections, which will be dealt with in detail in a second article.

[Therapeutic strategies for joint infections]

Joint infections represent a severe complication that results in irreversible joint destruction when left untreated or treated inadequately. The reasons for joint infections include endogenous hematological and exogenous factors. In the patient cohort described here, the empyema was almost exclusively acquired through iatrogenic measures (e.g. arthroscopic operations, punctures and intra-articular infections) or as a result of fractures close to the joint and penetrating injuries. Acute joint empyema is an orthopedic emergency, which must be immediately surgically treated because irreversible cartilage damage can rapidly occur due to the pathophysiological process. Acute joint empyema must be treated arthroscopically. Chronic empyema must be assumed when the clinical symptoms last for more than 7 days. Chronic empyema should be treated by arthrotomy, synovectomy and removal of extraneous material including cruciate ligament replacement material.

[Joint infections. Known facts and new trends]

Acute septic arthritis is a surgical emergency because rapid septic destruction of articular cartilage can lead to impairment or even loss of joint function. Diagnosis consists of patient history, clinical examination, laboratory results, (sonography- guided) joint aspiration and radiography. Emergency therapy is based on arthroscopic or open joint debridement and lavage combined with systemic antibiotic therapy. No data are available for the recommendation of local antibiotics but antiseptic solutions are not recommended because of cartilage damage. New trends in diagnostics are positron emission tomography/computed tomography (PET/CT), urine sticks for analysis of joint fluid and molecular pathology. Chronic joint empyema is more diagnostically demanding and is difficult to treat. In cases of necrotic and infected articular cartilage, joint resection has to be performed for quiescence of infection. Options following successful treatment of empyema are arthroplasty, arthrodesis or permanent resection.

Adult calcaneal osteitis: incidence, etiology, diagnostics and therapy

Calcaneal osteomyelitis presents a complicated situation. The specific anatomy of the os calcis and its surrounding soft tissues plays an important role in the planning and realization of the procedures needed in order to eradicate the osteomyelitic focus. The calcaneus represents a spongious bone; a fact that supports the developement of an osteomyelitis. It is the strongest bone of the foot and is highly important for the biomechanical features of physiological walking. The surrounding soft tissues are thin and contain various important anatomical structures. These might be damaged during the treatment of the osteomyelitis. In addition the vascularization of the os calcis is delicate and may be compromized during the surgical osteomyelitis treatment. Calcaneus osteomyelitis may be classified based on the routes of infection into exogenous and endogenous forms. Additionally from the clinical point of view acute and chronic forms may be distinguished from an early and a late infection. Exogenous calcaneal osteomyelitis mostly is the result of an infection with S. aureus. The treatment is equal to the therapy in other locations and based on: Eradication of the bone infectionSanitation of the soft tissue infectionReconstruction of bone and soft tissue Especially the preservation and restoration of the soft tissue is important. Thus plastic surgical procedures play an essential role. The main object of treatment is the preservation of a biomechanical functioning foot. This may be impossible due to the local situation. Calcanectomy or even below knee amputation may be needed in those cases.