In spite of making rapid strides in healthcare in the last few decades, tuberculosis is still a very common problem in India. A bug called Mycobacterium tuberculosis causes TB. Bone TB is the next most common site after lungs. Amongst bones, it is the spine (neck and back) that is the most common site of tuberculosis. Tuberculosis can strike anyone at any age and there may be no specific predisposing factor in most patients.
Children and elderly; people with decreased immunity; family history or past history of tuberculosis and patients who have had contact with a known case of tuberculosis are some groups that are prone to developing tuberculosis. Tuberculosis can affect any part of the spine from the upper neck to the tailbone.
Patients with tuberculosis of any part of the spine may complain of pain localized to that area, fever (especially in the evenings), weight loss, loss of appetite and a generalized feeling of being unwell. Their pain may be especially worse at night or during rest. Tuberculosis of the spinal bones can easily spread to the spinal cord resulting in weakness and numbness of extremities, paralysis and alteration of urine and motion pattern. It is this proximity to the spinal cord that makes TB spine a problem that cannot be taken lightly.
An X-ray followed by an MRI (may need contrast) will be required to make a diagnosis of Spinal TB. A basic work up for TB should include a Complete Blood Count (CBC), ESR, Liver Function Test (LFT) and a Chest X-ray.
Once a diagnosis of spine tuberculosis is confirmed, your doctor will start you on anti TB treatment (ATT) for 9-12 months. This will typically comprise of 4 drugs – Isoniazid, Rifampicin, Pyrazinamide and Ethambutol. Most patients improve on ATT but a few patients may need Spine Surgery in addition to ATT.
Your Spine Surgeon may recommend you to undergo a biopsy/FNAC to confirm the diagnosis of TB. A biopsy/FNAC is also recommended if your Spine Surgeon suspects Multi Drug Resistant TB (MDR – TB). Other infections, cancers and tumors can look like TB on X-rays and MRI. Therefore, a biopsy will confirm tuberculosis and rule out the other possibilities with absolute confidence.
In addition, cultures can be taken at the time of biopsy, which can tell your Surgeon as to what are the best anti-TB medicines that will kill the specific TB bug that has infected you. Culture will also identify cases with Multi Drug Resistant TB (MDR – TB). We recommend that TB cultures should be done using BACTEC-MGIT technique. TB culture can take a bit of time taking from 3-6 weeks with a few more weeks to know the drug sensitivity patterns. GENEXPERT is a new test that can be done on TB cultures. It can confirm the presence of TB bug within 2 days and also tell us if the bug is resistant to Rifampicin (main anti TB drug).
Surgery may be required for the following patients with Spinal tuberculosis:
- Weakness in hands or legs, paralysis or change in urine or motion pattern.
- When the diagnosis of TB is not confirmed and it is not safe to obtain biopsy/culture using a needle.
- When there is inadequate response to ATT
- Severe destruction of spinal bones
- Bed ridden patients
- Elderly patients
Surgery for spinal tuberculosis typically involved fixation (using Titanium plates or screws and rods), debridement (to clean the infected tissues of the TB bug), biopsy and TB cultures (using BACTEC-MGIT and GENEXPERT as available) and fusion. As against the traditionally held belief, it has been conclusively shown now that there is no problem with using metal work (Titanium) even in cases with active TB infection. Surgery alone cannot treat spinal tuberculosis and it is absolutely necessary to continue anti tuberculosis drug treatment (ATT) as prescribed by your doctor.
Other infections (bacterial, fungal, Brucella and typhoid bug) can present in a fashion absolutely similar to spinal tuberculosis. One cannot differentiate these infections from TB based on X-rays and MRI. Biopsy and culture is the only test, which can differentiate TB from these infections conclusively.