Spinal Tuberculosis.

Spinal tuberculosis (TB) is a significant form of TB, causing spinal deformity and paralysis. Early diagnosis and treatment are crucial for avoiding multivertebral destruction and are critical for improving outcomes in spinal TB. We believe that appropriate treatment method should be implemented at the early stage of this disease and that the Gulhane Askeri Tıp Akademisi classification system can be considered a practical guide for spinal TB treatment planning in all countries.

Introduction

Spinal tuberculosis (TB) is one of the oldest human diseases; it has been found in Egyptian mummies dating back 5000 years; the first case of spinal TB was described by Percival Pott in 1779.1,2 In the developing countries, spinal TB is one of the primary causes of spinal deformity and paralysis. According to the latest global (TB) report by the World Health Organization, an estimated 9.0 million people developed TB and 1.5 million died from TB in 2013 alone.3 TB affects the spine in 3%–5% of patients,4 and spinal TB is also known as Pott’s disease. Spinal TB is the most common and worst form of TB lesion.5

Diagnosis and Treatment

Early diagnosis is crucial for treating spinal TB. If patients are diagnosed early, they can be treated with the proper pharmaceutical drugs, such as antibiotics only. Early and definite diagnosis of this disease is not easy, as the disease progression is slow and insidious. Due to this difficulty, many patients in the early stages of the disease receive treatments, such as nonsteroidal anti-inflammatory drugs, physical therapy, or a corset (spinal support), prior to correct diagnosis.6,7

A positive skin test and elevated erythrocyte sedimentation rate (ESR) may be useful for diagnosing spinal TB, biopsy evaluation and DNA amplification techniques (polymerase chain reaction) may also facilitate the diagnosis. For histopathological examination, formalin-fixed and paraffin-embedded tissue blocks of biopsied specimens are stained with hematoxylin–eosin.8 Conventional radiography methods are used as first-step diagnostic methods, providing a good overview. Advanced imaging methods, such as magnetic resonance imaging (MRI), play an important role in detecting spinal TB earlier than other techniques and provide the possibility of earlier and more effective treatment before significant defects develop.9 Three-dimensional computed tomography (CT) scans and MRI reveal the involved vertebrae and attachments clearly.10 They can also exhibit the degree of intervertebral disk destruction, the scope of central lesions, the locations and number of cavities and abscesses, and spinal cord compression.11 MRI and CT facilitate and allow the diagnosis of spinal TB, but histopathological diagnosis remains essential.12,13

Pharmacological therapy usually consists of triple-drug antituberculous chemotherapy (p-aminosalicylic acid, streptomycin, and isoniazid) and plays a main role in TB treatment,12 if the lesion is without complications and limited to the vertebrae. Some studies14,15 have reported the worsening of existing symptoms or the appearance of new lesions in patients who initially responded well to antituberculous therapy. However, with the appropriate indications, surgery is considered superior for preventing neurological deterioration, maintaining stability, and early recovery.16–18 Surgical treatment of spinal TB aims at abscess debridement, which involves removing purulent necrotic tissues from normal tissue, spinal cord decompression, permanent spinal stabilization, and preventing or correcting deformity. Considering the serious burden caused by the high cost of medical treatment and surgical trauma, early diagnosis and treatment to avoid multivertebral destruction are critical to improve the outcomes in spinal TB.11

Classification Systems

Spinal TB is one of the most challenging diseases for surgeons to treat, and some guidelines are needed for appropriate decision making and treatment. Currently, there are few widely accepted classification systems based on objective data that can guide the selection of the proper treatment approach for patients with spinal TB. In 2008, Oguz et al19 developed a classification system (Gulhane Askeri Tıp Akademisi [GATA]) for spinal TB based on seven clinical and radiological criteria (abscess formation, disk degeneration, vertebral collapse, kyphosis [unnatural curvature of the upper back that creates a hunchback appearance], sagittal index, instability, and neurological problems). They also recommended specific techniques for each type.

Per the GATA classification system, spinal TB is divided into three types (IA/B, II, and III) using the abovementioned criteria (Table 1). Surgery is recommended for Type IB (abscess formation, one or two level disk degeneration, no collapse, and no neurologic deficit), Type II, and Type III patients with or without neurological deficit. They emphasize that if there is a cold abscess, antibiotic–analgesic therapy alone cannot prevent the extensive destruction of vertebral bone and disk material. After cold abscess and two-level disk degeneration, immediate drainage along with medical therapy can protect the patient from vertebral collapse. As long as the treatment plan is fully prepared, the surgical option can achieve a satisfactory curative effect in treating spinal TB, despite some complications. We believe that the appropriate treatment method should be implemented at the early stage of this disease and that the GATA classification system can be considered as a practical guide for spinal TB treatment planning in all countries.

Table 1

GATA classification system.

TYPE	LESION
Type IA	The lesion is limited to the vertebrae
Type IB	Abscess formation occurs; one or two-level disc degeneration
Type II	Collapse of vertebrae; abscess formation occurs; kyphosis; stable deformity with or without neurologic deficit; sagittal index (SI) is less than 20 degrees
Type III	A more severe vertebral collapse; abscess formation; severe kyphosis; deformity instability with or without neurologic deficit; SI is more than 20 degrees

Conclusion

Current treatment modalities (medical and surgical) have improved outcomes in the management of spinal TB, even in patients with neurological deficits and spinal deformities. However, there are various surgical or conservative treatment options, and heterogeneous outcomes have been described, which render the decision-making and selection of specific treatment options by surgeons difficult. Future investigations and publications require clear definitions of spinal TB to help guide the appropriate decisions and treatment by surgeons.