This article discusses bone tuberculosis, its causes, symptoms, diagnosis, and treatment.
Bone TB, also sometimes referred to as bone and joint TB, represents approximately 2–5% of all tuberculosis (TB) cases. Spinal TB, a subtype of bone TB, is the most common form of TB that spreads outside the lungs.
TB is an infectious disease that spreads through the air. The bacterium that causes it affects about a quarter of the world’s population, according to the World Health Organization (WHO).
Mycobacterium tuberculosis (M. tuberculosis), a species of bacteria, causes TB to develop. These bacteria spread through contact with respiratory droplets expelled from a person with the disease. TB typically affects the lungs, causing what doctors refer to as “pulmonary TB.”
M. tuberculosis can also affect other areas of the body. Experts use the term “extrapulmonary TB” to describe TB that spreads outside the lungs.
Bone TB and other types of extrapulmonary TB develop when TB spreads from the lungs. This can occur when the presence of M. tuberculosis goes undetected for a long time.
People with weakened immune systems are at high risk of developing extrapulmonary TB. This includes people with AIDS and those receiving chemotherapy.
Other risk factors, according to the Centers for Disease Control and Prevention (CDC), include:
- having an underlying condition, such as:
- silicosis, a lung condition
- diabetes
- severe kidney disease
- head and neck cancer
- having a low body weight
- using illegal substances
- undergoing medical procedures such as:
- corticosteroid therapy
- organ transplant
- specialized rheumatoid arthritis treatment
- specialized Crohn’s disease treatment
The symptoms of bone TB can proceed slowly but with serious effects. This can sometimes make the condition hard to recognize.
Symptoms of disease progression can include:
- back or joint inflammation
- stiffness
- difficulty moving
- severe pain in the affected area
- swelling
These symptoms can affect various bone areas, including the:
- spine
- knee
- foot
- wrist
- elbow
- shoulder
- ankle
- hip
Some people with bone TB may also develop tuberculous arthritis. Tuberculous arthritis is a condition that causes degenerative changes in the bone and joint cartilage.
Because the bacteria spread from the lungs, people with bone TB may also experience symptoms of pulmonary TB. These symptoms can include:
- persistent cough
- a loss of appetite
- night sweats
- high temperature
- weight loss
- fatigue
Contact your doctor right away if you are experiencing TB symptoms or if you think you may have been exposed.
Your doctor will begin the bone TB diagnostic process by asking some questions related to your symptoms and medical history. They may also perform several lab tests, including:
- Bacterial culture: This is a test that looks for signs of M. tuberculosis in a sample.
- Polymerase chain reaction (PCR) test: This is a technique that finds the DNA or RNA of a pathogen in a sample.
- Biopsy: This removes a small sample of bone for examination under a microscope.
- Chest X-ray: This studies your chest and nearby structures for signs of TB.
- Bone or joint X-ray: This takes images of your bones and joints for analysis.
- CT or MRI: These scans create images of your internal organs and can show signs of extrapulmonary TB.
Antitubercular drugs are the mainstay treatment for bone tuberculosis.
Your doctor will typically give you a combination of medications for 2 months, which may include:
- rifampicin (Rifadin)
- isoniazid (Isovit)
- ethambutol (Myambutol)
- pyrazinamide (Rifater)
- streptomycin (Rimosidin)
Afterward, your doctor will administer a combination of rifampicin and isoniazid for a period of 6, 9, 12, or 18 months.
Additional treatments may include corticosteroids and surgical procedures to remove diseased bone.
Bone TB is a serious condition, but early treatment can improve the outlook for people with the disease.
Research from 2020 found that antitubercular drugs have good penetration into spinal bones affected by TB. Another study from 2018 noted that 4 in 10 people with TB-induced paraplegia may recover with medical management alone.
For people with TB at a high risk of developing bone TB, preventive medications may help keep the disease from spreading outside the lungs. These medications include:
- isoniazid
- rifampicin
- fluoroquinolone
Measures that may help prevent developing TB and keep it from spreading include:
- taking extra care around people who have respiratory symptoms
- getting tested
- taking medication to keep a latent TB infection, which means the bacteria in your system are not causing symptoms, from developing into active TB disease
- taking all your medications if you have received a TB diagnosis
- isolating until your doctor has determined that you can no longer spread the disease
Nick Villalobos, M.D., reviewed the answers to these common questions about bone TB.
Can bone tuberculosis be cured?
Yes, it is possible to cure bone TB. Early detection of the disease is critical, and the affected individual must take their medications exactly as their doctors have instructed.
How do you get tuberculosis of the bone?
If you have pulmonary TB, or TB in your lungs, it may spread to other parts of the body. This may include the bones, in particular the spine.
How long does it take to treat bone TB?
Treatment for bone TB may take several months, up to a year and a half in some cases.
Bone TB occurs when TB spreads from the lungs to the bones. The most common type is spinal TB. Symptoms include swelling, stiffness, and severe back pain.
Experts have identified M. tuberculosis as the causative agent. This bacteria spreads through the inhalation of respiratory droplets expelled from a person with TB.
Your doctor can typically diagnose bone TB with standard tests, such as bacterial culture and bone X-rays. Treatments include antitubercular drugs, corticosteroids, and surgery.
Contact your doctor immediately if you are experiencing symptoms or if you think you may have been exposed to TB.
