Therapy
Conservative therapy is based on administration of analgesics, antipyretics and of course antibiotics. Even in this situation, before receiving the results of cultivation and sensitivity, we administer anti-staphylococcal antibiotics intravenously in high doses.
Surgical therapy is based on revision of the joint, evacuation of pus, excision of necrotic tissue, and instillation of a lavage or drainage system. Operative revision may be performed arthroscopically. In extensive cases and those with severe degenerative changes, a part of the procedure may include excision of bruised synovial linings known as synovialectomy. In the postoperative period, we temporarily immobilize the joint. Later we begin rehabilitation with passive movements of the joint. Prompt mobilization of the joint allows for the conservation of the greatest portion of movement for later stages of life.
Bone Tuberculosis
Definition
Tuberculosis in bones is a specific bone inflammation which includes the formation of specific granulation tissue, consisting of mostly modified histiocytes; neo-angiogenesis is practically absent. Immunologically, we detect a lack of free serum antibodies. In addition to tuberculosis, specific inflammations include syphilis and leprosy. From an orthopedic point of view, tuberculosis is the most severe of the specific inflammations.
Incidence
Tuberculosis is a very severe disease. Incidence, prevalence, and mortality of this disease has not changed in a very long time. Worldwide, approximately one-third of the population is affected, with 10% developing the disease. The most affected regions include Africa, Western Pacific, and Eastern Europe.
Etiology
The disease-causing agents is most often Mycobacterium tuberculosis, in rare cases we can also see other species from the mycobacterium genus including M. bovis, M. africanum, M. microti, M. canetti, M. pinnipedii. The target of the bacteria is primarily the lungs, with the pulmonary form of the disease being present in approximately 85% of patients. Usually, the bacteria spread to other systems, most often in patients with lowered immunity. Affection of the locomotor system is approximately in 1–3% of patients, of which 50% have an affected spine.
Pathogenesis
The bacteria most often enter via the respiratory system, rarely through the gastrointestinal system, direct contact or transplacentally. Immediately after entry, mycobacteria are introduced by macrophages into the regional lymph nodes. The primary focus and the regional lymph nodes form the so-called primary Gohn complex. In cooperation between macrophages and specific lymphocytes, an immune response is developed in which inflammatory mediators are released and the cellular defense response is activated. The result is the formation of a specific focus (granuloma), which is labeled as a tuberculous node (tubercle). A tubercle is a circular focus with a diameter of 1 to 2 mm, which may be gray and hard or even yellow and soft (with central caseation – soft tubercle). It contains epithelial cells, Langahn cells (formed by aggregation of histiocytes), surrounded by lymphocytes and in the case of a soft tubercle, caseation (macroscopically looks like a cheesy substance). From this focus, dissemination via lymphatic routes to other organs is possible, where other specific granulomas may be formed. Small granulomas are usually eliminated by the immune system, however large granulomas may become encapsulated and calcified. Mycobacteria may persist in the center of these deposits for a long time. When immunity is weakened, they may become reactivated. A typical morphological manifestation is tuberculous exudate, which in some places or completely succumb to caseation, which then affects surrounding tissue structures. Specific granulation tissue often develops on the periphery of the caseous masses, which may encapsulate the deposit. This process can be repeated until a chronic round lesion, called tuberculoma, is formed. Another characteristic trait of tuberculosis is the formation of so-called
migratory abscesses, which propagate (migrate) in the direction of gravity down the fascia and neuro-vascular bundles to distant locations (e.g. from the spine to the thigh). Migratory abscesses develop by the propagation of tubercles and their subsequent caseification. Tuberculosis of the locomotor apparatus affects spongy bone, synovial lining, and tendinous sheaths.
Clinical manifestation
The course is often inconspicuous, identical to other forms of tuberculosis, where the generalized symptoms (sub-febrility, anorexia, weight loss) dominate.
Subjective complaints. Pain is often insignificant and slowly progressing.
Objective findings. Swelling develops gradually, is not significant, with little pain upon palpation, and is sometimes intermittent. The associated effusion is mild and turbid. Muscle atrophy soon develops.
Diagnostics
It is important to consider the possibility of tuberculosis infection! Examining the health history, we focus on possible contacts with ongoing pulmonary tuberculosis, past infections, injuries, work, social, travel history and professional workload (especially health professionals and veterinarians). The key to diagnosis is good tissue collection, preferably before starting ATB or anti-tuberculosis treatment.
Laboratory examination. As part of the standard diagnosis, we may encounter leukocytosis, with CRP and ESR slightly increased. In serological tests, IgG antibodies can be detected (positivity expresses the immune response to frequent contact with tuberculosis), IgM (high positivity occurs with massive exposure to TB antigen in a short amount of time, IgM usually disappears promptly after exposure).
Tuberculin skin test (Mantoux). It is performed via an intradermal application of 2 units of purified protein derivative from tuberculosis bacilli to the dorsal side of the forearm, and is examined after 72 hours. Swelling with a diameter of 5 mm or more is evaluated as a positive test. With the elderly patient or patients with immunodeficiencies, the tuberculin skin test may interpreted as a false negative.