ABOUT
Like any other bone, the spine can also be the seat of infections, both pyogenic or tubercular. Spinal tuberculosis is the most common site of bony tuberculosis. Several vertebrae can be rapidly destroyed leading to a collapse of the bony structure and an unsightly 'Hunch Back' deformity. Children are especially more prone to developing the deformity as the deformity can continue to progress even after the disease has been cured. This can subsequently lead to severe compression and stretching of the spinal cord with resultant paralysis of both the lower limbs.
In the early stages of the disease, use of anti-tubercular drugs is sufficient for complete cure. However, in severe cases and in patients who have weakness or paralysis of legs, surgical decompression of the spinal cord along with medication becomes an important consideration. Surgery removes the pressure effect on the spinal cord, prevents progressive deformity and gives good relief of pain. Implants made of specialized metals and bone grafts are used to stabilize the spine while the healing process ensues.
Spinal tuberculosis is caused by Mycobacterium tuberculosis. Infection results from hematogenous dissemination from a primary focus, usually the lungs, although the associated active focus is identified in only less than 10%. The most common site of infection is the paradisical type, where two adjacent bones on either side of a disc are commonly involved.
SYMPTOMS & DIAGNOSIS
The following are the symptoms of Spinal Tuberculosis and diagnostic steps.
Back pain associated with restriction of movements of the spine is the usual presenting feature. Constitutional symptoms of malaise, loss of appetite and weight, evening rise of temperature and night sweats are also common but can be absent in patients with good nutrition. As the disease progresses, the collapse of the spine is evident with the prominence of the spinous process as a sharp deformity in the early stages and a very prominent deformity (kyphosis) in late stages. Tuberculosis can present with huge abscess formation. This is called a cold abscess due to lack of high-grade fever and warmth and may be clinically evident in the back. The pus and the bending deformity can cause pressure on the spinal cord resulting in various grades of paralysis. Neurological involvement initially presents as in-coordination, clumsiness while walking and slowly progresses to paralysis.
In the blood tests, erythrocyte sedimentation rate may be markedly elevated (> 70 mm/ hr), and serial ESR measurements also help in assessing the response to treatment. The white cell counts are raised with particular raise in the lymphocytes. Xrays show bony destruction and deformity. CT is useful in assessing accurately the extent of bony destruction, early identification of posterior element involvement, and in tuberculosis of specific sites like the craniovertebral and cervicodorsal junction, the sacroiliac joints and the sacrum. MRI is the gold standard for demonstrating the extension of disease into soft tissues and the spread of tuberculous abscess. MRI is the most effective method for demonstrating spinal cord compression. The diagnosis is confirmed by histopathological ("biopsy") examination of the infected tissue.
TREATMENT
General supportive measures include bed rest, external bracing, nutritious diet, vitamins as required, care of bladder, bowels and good nursing care. Modern anti-tubercular drugs are able to achieve excellent clinical cure. Hence spinal TB is considered as a medical disease with selected surgical indications. Multidrug chemotherapy is administered for all the patients and bed rest with external bracing is advised in the initial period. The patient is followed carefully until complete healing. Surgical treatment is recommended for certain specific indications like the extensive neurological deficit, severe pain, instability, deformity of the spine and lack of expected response to medications. The currently recommended first-line drug regime is four-drug therapy. This includes Isoniazid 5 mg/kg, Rifampicin 10 mg/kg, Pyrazinamide 20 – 25 mg/kg, and Ethambutol 15 mg/kg for two to three months followed by Isoniazid and Rifampicin for four to six months. The aims of surgery in spinal tuberculosis are to obtain a tissue sample for biopsy, drain an abscess cavity, achieve debridement of disease focus and to stabilise the spine.