Bone Tuberculosis TB: Symptoms, Causes, Types, Treatment & Diagnosis

Tuberculosis (TB) is a highly contagious disease caused by the bacteria Mycobacterium tuberculosis, carrying a high fatality rate globally. Although the lungs are the most common site of TB infection, this disease can easily spread to other parts of the body. Fortunately, TB is a preventable and curable disease if detected in its early stages.

When TB spreads beyond the lungs and affects the bones, it is known as bone TB or skeletal tuberculosis. While a significantly lower number of individuals are affected in the musculoskeletal system globally, the spine is a typical target. However, any bone in the body can be susceptible to tuberculosis. The infection typically spreads from the lungs to the bones or joints via the bloodstream, with the dense blood supply in the center of long bones being a common site for its onset.

Although bone tuberculosis is uncommon, its frequency has unfortunately risen in recent years in developing nations, primarily due to the increase in AIDS cases. If left untreated for a long time, bone TB can cause serious complications and is notoriously challenging to detect due to its subtle symptoms. Unlike pulmonary tuberculosis, which transmits through airborne droplets, research suggests bone TB is not transmitted by air or droplets; rather, constant contact with pus can cause the infection to travel into the bloodstream and transmit the disease.

Diagnosis of Bone TB

If you experience any symptoms suggestive of bone TB, your doctor may recommend imaging tests such as an MRI, X-ray, or CT scan. A biopsy, which involves removing and analyzing a sample of contaminated tissue, may also be recommended to confirm the diagnosis.

PCR (Polymerase Chain Reaction) can also be used to analyze samples, amplifying the mycobacterium's genetic material for detection even from very low fluid volumes. Given the high chance of lung involvement with bone TB, your doctor may also take a blood or sputum sample to check for Mycobacterium tuberculosis, or other bodily fluids to test for TB and, in some situations, AIDS antibodies.

In cases of suspected infection, your doctor might collect a sample of excess fluid from areas around your lungs. If bone TB is specifically suspected, fluid surrounding your joints may also be drained for further analysis to aid in diagnosis.

Treatment for Bone TB

The primary treatment for bone TB involves adhering strictly to medication prescribed by your doctor, with the course typically ranging from six to eighteen months. Commonly prescribed drugs for patients exhibiting bone TB symptoms include Pyrazinamide, Ethambutol, Rifampicin, or Isoniazid.

It is crucial to identify the signs of bone TB as soon as possible. This condition can lead to severe issues like bone destruction and thoracic deformation. If detected in its early stages, bone tuberculosis can be successfully treated. A TB blood test typically costs between 1600 to 2000 rupees, with results usually available within 48 hours.

Even after overcoming TB in the past, re-infection is possible and becoming increasingly prevalent. It is important to note that, unlike pulmonary tuberculosis, bone tuberculosis is not contagious through the air unless there is direct contact with a patient's pus. The diagnosis of bone tuberculosis can be particularly challenging as it often does not present with traditional signs like high fever or unusual weight loss.