Causes and risk factors
Mycobacterium tuberculosis bacteria enters the lungs through inhalation of droplets released into air [sneeze, cough, sputum, spit] by a tuberculosis infected person. Primary focus is usually formed in the lungs. Secondary focuses occur via blood or lymph to other organs like gastrointestinal tract, kidney, liver, bones, and brain. After dissemination to the bone and joints, the disease starts in synovium and grows over to the cartilage. It extends from cartilage to underlying bone resulting in decalcification. Destruction of articular cartilage occurs. Fibrous ankylosis develops later. Purulent material accumulates in the joint space. There is also formation of cold abscess or sinuses.
Clinical presentation
Tuberculosis of bones and joints mainly affects the spine, hip, knee, elbow, wrist, hands, and shoulder. Spine and knee are commonly affected. It is usually seen in children and young adults. Patient complains of pain and stiffness in the bones and joints. In case of leg involvement, there is presence of limp in walking. The affected joint is filled with exudative fluid and there is muscle wasting around the joint or affected bone. There is effusion of synovial joint. Constitutional symptoms like low-grade fever, weight loss, loss of appetite, night sweats are experienced. Enlargement of lymph nodes may be seen.
Investigation
Medical history by the patient and clinical examination by the doctor helps in diagnosis. Imaging techniques such as x-ray of bones and joints is recommended. Mantoux tuberculin test [though not much of a reliable technique] is done for screening of high-risk patients. A chest x-ray and multiple sputum cultures for presence of acid fast bacilli are initial evaluation methods. Synovial tissue biopsy is obtained for identification of mycobacterium tuberculosis bacteria. Detection of bacteria in the synovial fluid is done by AFB staining. An Xpert MTB/RIF rapid, fully automated nucleic acid amplification test has been introduced recently for rapid diagnosis of TB. Imaging techniques such as CT scan, MRI of bone may help in further evaluation.
Treatment
Antimicrobial or antitubercular drug is the treatment for TB of bones and joints. Multiple drug therapy is highly effective treatment. DOT [directly observed therapy] reduces the chances of relapse as it is a supervised therapy. Newer drug regimen is advised for MDR TB and XDR TB. Prevention is done with BCG vaccination at birth. Orthosis or braces to correct postural deformities are helpful. Surgical intervention is required to aspirate or tap large synovial effusion or other joint deformities with complications.
Other Modes of treatment
The other modes of treatment can also be effective in treating TB of bones and joints. Homoeopathy is a science which deals with individualization and considers a person in a holistic way. This science can be helpful in combating the symptoms. Similarly, the Ayurvedic system of medicine which uses herbal medicines and synthetic derivates are also found to be effective in treating TB of bones and joints.
