➢ Mycobacterium tuberculosis infection of the spine is resurgent in all parts of the world, with atypical clinical and radiographic presentations becoming increasingly common.
➢ Short-course ambulatory anti-tubercular chemotherapy is the mainstay of treatment. Multi-drug management is essential to prevent drug resistance and disease recurrence.
➢ The natural history of spinal tuberculosis in children is different from that in adults as children are prone to more deformity throughout the period of growth even after the disease has been cured. The detection of “spine-at-risk” radiographic signs will allow for the early identification of children who are prone to develop progressive deformity and to require operative stabilization.
➢ Surgical debridement, decompression, and stabilization are needed in patients with severe neurological deficits, extensive vertebral destruction, and deformity.
➢ Both anterior and posterior surgical debridement and stabilization can be performed, and both procedures have similar outcomes. Titanium implants can be used safely even in patients with active disease because tubercle bacilli do not adhere to metal or form biofilm.
Spinal tuberculosis constitutes >50% of cases of skeletal tuberculosis1. Although the disease still predominantly afflicts the underprivileged population in developing countries, it has been increasingly reported in economically developed countries worldwide2. The increased incidence of human immunodeficiency virus (HIV), immunodeficiency due to diabetes, chemotherapy for the treatment of cancer, old age, and a steady increase in global travel and immigration have all helped to maintain tuberculosis as a global disease2,3.
In recent years, the clinical and radiographic features of spinal tuberculosis have changed considerably. Atypical presentations are more common, making clinical suspicion and histopathological confirmation essential4.
Powerful anti-tubercular therapy is usually sufficient for the treatment of uncomplicated spinal tuberculosis, and operative intervention is advised only for specific indications to prevent and treat complications5.
The global burden of tuberculosis remains enormous. The World Health Organization (WHO) Global Tuberculosis Report of 2012 stated that there were an estimated 8.6 million new cases of tuberculosis and that 1.3 million people died of the disease6. Among those who died, 170,000 had multi-drug-resistant tuberculosis. The South-East Asia and Western Pacific regions collectively accounted for 58% of the tuberculosis cases worldwide in 20126.
The exact incidence and prevalence of spinal tuberculosis are not known. In developing parts of the world with a high burden of pulmonary tuberculosis, the incidence is expected to be proportionately high7. The WHO tuberculosis report indicated that, in 2012, India and China had the largest number of tuberculosis cases (26% and 12% of the global total, respectively)6. In developed nations, spinal tuberculosis is uncommon. Talbot et al. studied the epidemiology of skeletal tuberculosis in the United Kingdom and observed that, of 729 patients with tuberculosis, the majority (74%) were immigrants from the Indian subcontinent3. According to the Centers for Disease Control and Prevention, a total of 9945 tuberculosis cases (a rate of 3.2 cases per 100,000 persons) were reported in the United States in 2012. Of these, 63% occurred in foreign-born persons. The rate among foreign-born persons was approximately eleven times higher than that among persons born in the United States.
Tuberculosis is also the most common HIV-related opportunistic infection worldwide7-9. In the Nigerian study by Iliyasu and Babashani, 10% of 1320 HIV-infected patients were co-infected with tuberculosis9. Of the thirty-five patients with extrapulmonary tuberculosis, 14% had spinal tuberculosis. Genetic susceptibility to spinal tuberculosis was recently demonstrated by Zhang et al., who observed an association between the FokI polymorphism in the vitamin-D receptor gene and spinal tuberculosis in the Chinese Han population10.
Tuberculosis is caused by a bacillus of the Mycobacterium tuberculosis complex7,11,12. Currently, there are sixty known species among the Mycobacterium genus, but only a minority of these species cause tuberculosis, including Mycobacterium tuberculosis (the most common), Mycobacterium bovis, Mycobacterium microti, and Mycobacterium africanum. Vertebral infection by the bacillus results from hematogenous dissemination from a primary focus. Infection in the vertebral marrow is followed by a chronic inflammatory response characterized by epithelioid cells, Langhans giant cells, lymphocytes, and inflammatory exudates, which together constitute the typical histopathological lesion called the tubercle. With progressive destruction, caseous necrosis occurs to form the cold abscess.
The most common pattern of tubercular spinal infection is the “paradiscal” type, in which the bacilli lodge in the subchondral marrow on either side of the disc. The other types of spinal tuberculosis are the so-called centrum type (characterized by vertebral body destruction), the posterior type (characterized by involvement of posterior elements), and the non-osseous type (characterized by extensive abscess formation)13.
Tuberculosis of the spine is a chronic disease with an insidious onset. Pain, neurological deficit, cold abscess, and kyphotic deformity are the characteristic features of spinal tuberculosis13,14. In previous studies, 90% to 100% of patients with spinal tuberculosis have had back pain15-17. Azzam and Tammawy, in a study of twenty-three adult patients with tuberculous spondylitis, reported that all patients (100%) had back pain as the presenting symptom15. Hayes et al. observed that twenty (95%) of twenty-one patients had back pain17. The rate of neurological involvement has ranged from 32% to 76% in different studies16,18,19, and such involvement can occur both in the active phases of the disease and in the healed stages20. Jain et al. reported that seventeen (57%) of thirty patients with spinal tuberculosis presented with neurological deficit18. Hayes et al. observed that ten (47.6%) of twenty-one patients had neurological deficit17. In patients with active lesions, neurological deficit is the result of direct cord compression by an abscess, granulation tissue, sequestrum, or canal compromise due to instability20. In the late stages, it is due to stretching of the cord over an osseous ridge at the apex of the deformity20. A paravertebral cold abscess is a diagnostic feature of spinal tuberculosis and is observed in at least 50% of such cases14,21,22 (Fig. 1).
As the disease progresses, collapse of the vertebral body or bodies is evident as a localized kyphotic deformity. This deformity can manifest as a knuckle deformity (collapse of a single vertebra), gibbus deformity (collapse of two or three vertebrae), or global rounded kyphosis (involvement of multiple adjacent vertebrae)23-27. The pattern of progress of deformity differs between adults and children27. In adults the kyphosis progresses during the active stage of the disease and the final deformity is related to the extent of vertebral body damage28, whereas in children the kyphosis can worsen during the period of growth even after the disease has been cured29. Rajasekaran described four “spine-at-risk” radiographic signs with which children at potential risk for progressive kyphosis can be identified at an early stage25. Children with two “spine-at-risk” signs are at serious risk for a gross increase in deformity (Fig. 2). Hence, children with healed tuberculosis need periodic follow-up until the completion of growth.
Pertuiset et al. reported weight loss in 54% (fifty-six) of 103 patients16. Constitutional symptoms of malaise, evening rise of temperature, and night sweats are also common but are more typical of pulmonary tuberculosis; Hayes et al. observed these constitutional symptoms in 71% (fifteen) of twenty-one patients with spinal involvement and noted that they were more common in patients with associated malnutrition17.
Any patient with tuberculosis of the spine who does not present with such typical features (either clinical or radiographic or both) are considered to have an atypical presentation (Fig. 3)4. Pande and Babhulkar, in a study of 184 patients, reported the incidence of atypical spinal tuberculosis be 2.1%4. Of importance is the presence of multifocal spinal tuberculosis. The prevalence of multifocal spinal tuberculosis varies depending on the type of investigation that is used to evaluate the lesion; in previous studies, the prevalence has ranged from 1.1% (two of 184) when conventional radiographs were used to 71.4% (ten of fourteen) when whole-spine magnetic resonance imaging (MRI) was used30-32.
Standard blood tests that are used for the evaluation of tuberculosis include the erythrocyte sedimentation rate (ESR) and the C-reactive protein (CRP) level. The ESR is elevated, generally by >20 mm/hr, in 60% to 83% of patients with tuberculosis33,34. In the study by Hosalkar et al., twelve (67%) of eighteen patients with skeletal tuberculosis had an elevated ESR34. Rasool reported that the ESR was increased in thirty-five (83%) of forty-two patients with osteoarticular tuberculosis (mean, 61 mm/hr; range, 33 to 108 mm/hr)33. However, the ESR lacks specificity and can be increased even in patients with noninfectious conditions34,35. Guo et al. reported that the CRP level was increased in 69% (forty-six) of sixty-seven patients but noted that an elevated CRP level is more specific for acute infectious lesions36. Total and differential leukocyte (lymphocyte) counts can be elevated but lack a defined role in the diagnosis of spinal tuberculosis37.
Serological tests assessing the response of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to various tuberculosis antigens have been studied. Jain et al. reported a decrease of IgM titer and an increase of IgG titer at three months after successful treatment37. However, there are no specific antigens that can confirm an active tuberculous infection as they cannot differentiate between active and healed disease or between natural infection and BCG (bacillus Calmette-Guérin) vaccine-induced reaction. Hence, these serological tests are no longer recommended for the diagnosis of active tuberculosis38.
The tuberculin skin test is endorsed by the WHO for use in low-income countries and countries with high tuberculosis load and is positive for 62% to 90% of patients with tuberculosis33,39,40. Rasool reported that the tuberculin test was positive for thirty-eight (90.5%) of forty-two children with osteoarticular tuberculosis33. Nussbaum et al. reported that the tuberculin skin test was positive for eighteen (62%) of twenty-nine patients with spinal tuberculosis who had been followed for an average of 7.4 years39. The interferon-gamma (IFN-γ) release assays (IGRAs) (QuantiFERON-TB and QuantiFERON-TB Gold-in-Tube; Cellestis, Melbourne, Australia) are whole blood-based enzyme-linked immunosorbent assays measuring the amount of IFN-γ produced in response to Mycobacterium tuberculosis antigens. Kumar et al., in a study of fifty-one consecutive patients with tuberculosis of the spine, reported that the QuantiFERON assay had an estimated sensitivity of 84% and an estimated specificity of 95%41.
Polymerase chain reaction (PCR) analysis of tissue samples is considered to be very sensitive and specific for the diagnosis of spinal tuberculosis. PCR analysis of tissue aspirate for the diagnosis of tuberculosis has been reported to have a sensitivity of 73.1%, a specificity of 93.7%, and a low rate of false-positivity results (13.6%)42,43. The positive agreement between histopathological findings and the results of PCR analysis has been reported to be very good (0.69)43.
Bacterial culture of the infected tissue is useful for confirming the diagnosis and for acquiring antibiotic sensitivities. The most common solid medium is Löwenstein-Jensen medium. The rate of positive detection with this method has ranged from 0% to 75%44-46. Mateo et al., in a study of fifty-three patients with osteoarticular tuberculosis (thirty-seven of whom had spinal involvement), reported that the diagnosis of tuberculosis was confirmed on the basis of a positive culture in forty patients (75%)46. Agar media (BACTEC; Becton Dickinson, Franklin Lakes, New Jersey) are the current standard and allow for the early assessment of drug susceptibility. In a comparative study, BACTEC and Löwenstein-Jensen media had positivity rates of 83.87% and 61.29%, respectively, with the average detection time being 11.3 and 26.7 days, respectively47. The Xpert MTB/RIF test (Cepheid, Sunnyvale, California) detects DNA sequences specific for Mycobacterium tuberculosis and rifampicin resistance by means of PCR in ninety minutes. Steingart et al., in a recent Cochrane review, showed that this test was highly accurate and, when compared with culture, had a sensitivity of 88% and a specificity of 98%48. The diagnostic confirmation of tuberculosis infection is achieved through the identification of bacillus or through histological confirmation of typical tubercles in the infected tissue. Histological studies can confirm the diagnosis of spinal tuberculosis in approximately 60% of patients7,46. Mateo et al. reported that thirty-three (62.3%) of fifty-three patients had positive histological evidence of tuberculosis46. The most common histological findings are inflammatory lymphocytic infiltration, multinucleated and Langhans giant cells (56%; fifteen of twenty-seven patients)49, and epithelioid granuloma (70%; forty-eight of sixty-nine patients)50.
The earliest features observed on radiographs are vertebral osteoporosis, narrowing of the joint space, and indistinct paradiscal margins of the vertebral bodies51,52. Progressive destruction leads to vertebral collapse, kyphosis, and sagittal or coronal instability. Computed tomography (CT) scanning is useful for assessing the extent of osseous destruction, posterior element disease, and infections of the craniovertebral and cervicodorsal junctions and the sacroiliac joints, which are not easily seen on radiographs51,52. MRI is the gold standard imaging tool for demonstrating the extension of disease into soft tissues, the spread of tuberculous abscess, and neural compression53 (Fig. 1). MRI is useful for differentiating tuberculous spondylitis from pyogenic infections. Jung et al., in a study of fifty patients with spinal infections, observed that certain MRI features (including a well-defined paraspinal abnormal signal, a thin and smooth abscess wall, a combination of both findings [specificity, 90%], paraspinal or intraosseous abscess, subligamentous spread, involvement of multiple vertebral bodies, and involvement of the thoracic spine) favored a diagnosis of tuberculous spondylitis53. Jain et al. observed that occupancy of as much as 75% of the canal by extrinsic compressive elements such as abscess or sequestrum, as seen on axial MRI scans, was compatible with an intact neurological state54.
Serial MRI can be used to assess the response to treatment and regression of the disease. The healing of the vertebral lesion is diagnosed on follow-up MRI as complete resolution of marrow edema and paravertebral collections and replacement of marrow by fat. In the study by Jain et al., only twenty of forty-nine patients had complete radiographic features of healing55.
Multi-drug anti-tubercular chemotherapy forms the foundation for the treatment of spinal tuberculosis (Fig. 4). Multi-drug chemotherapy is essential in cases of tuberculosis because different types of bacilli (e.g., dormant bacilli, rapid multipliers, and intracellular and extracellular bacilli) exist in each colony, with different growth kinetics and metabolic characteristics56. A combination of drugs is also used to reduce de novo drug resistance57. The first-line drugs (isoniazid, rifampicin, ethambutol, pyrazinamide) are the most effective group of agents active against tuberculosis. Second-line drugs (e.g., ciprofloxacin, levofloxacin, kanamycin, capreomycin, cycloserine, etc.) are less effective, more toxic, and more expensive58. Spinal tuberculosis is classified as a severe form of extrapulmonary tuberculosis and hence should be given WHO Category-I treatment59. Intermittent short-course chemotherapy and directly observed treatment, short course (DOTS) have been found to be clinically effective in a large number of trials60-63. Short-course chemotherapy has many inherent advantages, such as improved patient compliance, lower failure rates, lower cost, and a lower rate of drug resistance.
Resistance to both isoniazid and rifampicin is termed multi-drug-resistant tuberculosis, and resistance to isoniazid and rifampicin along with resistance to any fluoroquinolone and at least one injectable second-line anti-tuberculosis drug is termed extensively drug-resistant tuberculosis. The increasing incidence of drug-resistant tuberculosis, especially when associated with co-infection with HIV, is one of the major global health threats today. Multi-drug resistance is usually the result of inappropriate drug therapy. The median prevalences of primary and acquired multi-drug-resistant pulmonary tuberculosis have been reported to be 3.4% and 25%, respectively64,65. The exact prevalence of multi-drug-resistant tuberculosis among patients with spinal tuberculosis is not known.
Telenti et al. showed that almost all rifampin-resistant isolates had mutations in the beta subunit of rpoB, a finding that subsequently has been detected in as many as 95% of resistant isolates66,67. Since then, the molecular mechanism of resistance to isoniazid, pyrazinamide, streptomycin, ethambutol, and fluoroquinolones has been described68-70. The treatment of multi-drug-resistant tuberculosis is extremely difficult71,72. All efforts must be made to culture the bacilli and to determine drug sensitivity. Regimens should consist of a minimum of four drugs that have not been used previously, and the minimum recommended duration of treatment is twenty-four months. Pawar et al. reported on twenty-five patients with multi-drug-resistant tuberculosis of the spine who required twenty-four months of chemotherapy73. Almost 50% of the patients had adverse drug effects. The authors identified five predictors for successful treatment of multi-drug-resistant tuberculosis, including progressive clinical improvement at six months, radiographic improvement during treatment, and infection with Mycobacterium tuberculosis strains exhibiting resistance to three anti-tubercular drugs or fewer, the need for use of only four second-line drugs or fewer, and no need for change of regimen during treatment.
The availability of effective anti-tubercular drugs has made surgery on the diseased area possible without dissemination of infection. The standard treatment for spinal tuberculosis initially was universal anterior excision surgery in conjunction with anti-tubercular drugs74-77. Although radical surgery provided good disease clearance, complications due to morbidity associated with the approach, vascular complications, prolonged surgery, neurological deficits, and the problems of bone defects and grafting were increasingly recognized24,78-80. The Medical Research Council (MRC), United Kingdom initiated a series of studies in which patients were randomly allocated to treatment with chemotherapy, debridement, or radical debridement plus anterior spinal fusion61,81,82. The five, ten, and fifteen-year results indicated that all three groups achieved the same favorable outcome. The study by Parthasarathy et al. also demonstrated that the results achieved after ambulatory short-course chemotherapy were equal to those of radical surgery supplemented with chemotherapy83. The MRC studies focused on cure of the disease as the outcome, and the two important aspects of neurological involvement and progressive deformity unfortunately were not considered for evaluation.
To resolve the conflict between radical surgery and conservative therapy, Tuli proposed the “middle-path regime,” in which chemotherapy is the mainstay of treatment and surgery is advocated only under special circumstances5. This approach has been adopted, and the indications for surgery have become more selective to prevent complications such as neurological deficit, pain due to pseudarthrosis, and deformity. The current indications for operative treatment are given in Table I.
Surgical Techniques and Approaches
Currently, operative treatment is performed to achieve debridement and drainage of large cold abscesses, decompression of the spinal cord and neural structures, prevention of instability, and correction or prevention of deformity. The traditional techniques involving anterior approaches have given way to predominantly posterior approaches because of the development of newer approaches such as transpedicular and transfacetal decompression and anterior reconstructions. Irrespective of the approach, pedicle screw instrumentation and anterior cages are increasingly used for stability and reconstruction. Oga et al. showed that tubercle bacilli, unlike pyogenic organisms, do not adhere to metal or form any biofilm84. A number of studies have shown that titanium cages can be safely used to reconstruct anterior column defects in the presence of infection13,19,85-87.
Anterior techniques were developed on the principle that spinal tuberculosis is a disease that mainly affects the anterior column, and therefore an anterior approach will allow maximum exposure for adequate debridement and reconstruction of the defect74,77,88. Initially, debridement alone without reconstruction of the anterior column was performed for the control of infection, but such treatment did not prevent the development or progression of deformity63,82,89. Hodgson et al. popularized the concept of anterior radical debridement and placement of rib strut grafts88. Although the procedure yielded satisfactory results88,90, the good results could not be replicated in all of the published series24,78-80. Vidyasagar and Murthy, in a series of ninety-one patients who were managed with thoracotomy, reported that seven patients died of respiratory failure78. Adendorff et al. observed increased mortality after thoracotomy, depending on the severity of neural deficit79. Without anterior instrumentation, the rate of graft-related complications has ranged from 23% (forty-two of 180 patients)91 to 59% (forty-eight of eighty-one patients)24, with a higher rate observed when more than two vertebral bodies have been involved24.
After debridement, the anterior column can be reconstructed with use of autograft, structural allograft, or a cage, with equivalent results (Fig. 5). Autogenous iliac crest grafts and rib grafts are commonly used to achieve interbody fusion92,93. Hodgson et al. recommended the use of iliac crest block graft to achieve better union as it covers the entire width of the vertebral body88. Louw described the use of vascularized rib graft, with radiographic fusion reported in 95% (eighteen) of nineteen patients at six months94. Fibular grafts also may be used when the defect involves more than two vertebrae95. Jin et al. analyzed twenty-three patients with active thoracolumbar spinal tuberculosis who were managed with one-stage anterior interbody autografting and instrumentation96. Neurological deficits were found in fifteen patients. All patients had healing, and a mean of 18° of kyphosis correction was achieved. Fibular and femoral ring allografts can be used as a substitute for or supplement to autograft95,97. Govender and Parbhoo reported a good rate of fusion in association with the use of fresh-frozen humeral allografts for the reconstruction of the anterior column after debridement98. Cavuşoğlu et al., in a study of twenty-two patients with multilevel spinal tuberculosis who underwent anterior radical debridement and fusion with use of tibial allografts, reported that all patients demonstrated clinical and radiographic healing after a mean duration of follow-up of eighty-four months99. The mean late postoperative kyphosis correction was 74% (range, 63% to 91%).
The use of a cage with bone graft instead of a structural bone graft alone allows for more secure, accurate, and dependable deformity correction and minimizes the risk of graft subsidence or dislodgement13,19,85-87. Christodoulou et al., in a retrospective study of twelve patients who had been managed with radical debridement and reconstruction with an anterior interbody titanium cage and autologous bone graft, reported that the mean kyphotic deformity had been corrected from 24.6° to 10°85. Anterior instrumentation with a plate or rods is commonly performed after vertebral body reconstruction100-103. A single-rod screw suffices in most patients, but a double-rod screw system may be necessary if the corrected kyphosis is large or the vertebral dimensions are wide enough to accommodate two screws. Benli et al. compared results of anterior plate systems with those of anterior rod systems after debridement and fusion and found that there were no significant differences between the two systems in terms of sagittal alignment reconstruction and fusion rate101. Complications associated with anterior instrumentation are cage migration, major vessel injury, displacement of screws, and injury to viscera100-103.
Concomitant posterior instrumentation after anterior reconstruction is indicated to protect the anterior bone graft, to prevent graft-related complications in patients with long-segment disease, and to correct kyphosis. Combined anterior and posterior procedures can be undertaken in one or two stages35,104,105. Moon et al. described a two-stage procedure in which the spine is first stabilized with posterior instrumentation, followed by anterior decompression and bone-grafting two to three weeks later106. The preoperative kyphosis improved from 37° preoperatively to 15° immediately postoperatively. Chen et al. reported on thirty-two consecutive patients who were managed with a two-stage procedure involving anterior debridement and fusion with iliac bone graft, followed by posterior instrumentation and fusion at a mean eleven days (range, four to twenty-two days) later107. Kyphotic deformity improved in all twenty-nine patients who were available for follow-up; the mean deformity improved from 34.6° to 17.3°. The authors observed that, in order to allow for fixation of the anterior spinal implant to the adjacent, unaffected vertebrae, the surgical dissection needs to be wider, which can be associated with more complications.
Combined approaches also can be performed in a single stage87,108,109. Sundararaj et al., in a large series of eighty-four consecutive patients who were managed with anterior decompression and posterior stabilization, observed that the mean duration of the combined anterior and posterior single-session procedure was five hours and that the mean blood loss was 1000 mL109. The mean length of hospital stay was 12.6 days (range, eight to fourteen days). Anterior decompression and concomitant posterior instrumentation can be performed through a single T-shaped incision to access both columns simultaneously. Jain et al. reported on thirty-eight consecutive patients for whom anterior decompression and posterior instrumentation were performed in a single stage through an anterolateral extrapleural approach108 The mean kyphosis improved from 49.08° preoperatively to 25° postoperatively. The authors reported that the advantage of this approach was that the simultaneous visualization of the anterior and posterior columns of the spine allowed for the achievement of adequate decompression and posterior stabilization87.
The posterior approach is being increasingly performed by many surgeons, and the reported advantages include the familiarity of the approach, decreased morbidity, excellent exposure for circumferential spinal cord decompression, the ease of extension of the instrumentation for multiple levels, better control of deformity correction, and the ability to safely perform simultaneous anterior reconstruction110,111. The transpedicular and transforaminal routes serve as excellent portals for debridement of the vertebral body and decompression of the spinal cord. In patients with early disease with less deformity, a posterior transpedicular decompression with stabilization alone provides immediate pain relief and prevents severe deformity and neurological sequelae110-112. Chacko et al., in a study of eleven patients with spinal tuberculosis who were managed with transpedicular decompression alone without instrumented stabilization, reported that the mean kyphosis worsened from 26.3° preoperatively to 31.25° at the time of the latest follow-up, although the functional outcome was good113. Sahoo et al., in a study of eighteen patients who were managed with posterior decompression and transpedicular screw fixation, reported that the mean kyphosis improved from 17.7° preoperatively to 11.6° at the time of the latest follow-up114. Neurological recovery occurred in seventeen patients (94.4%).
In patients with advanced disease, the transpedicular or extrapedicular route also can be used to place bone grafts or an interbody cage to achieve deformity correction and anterior vertebral reconstruction (Fig. 6). Zhang et al. recently reported on fourteen patients with upper thoracic tuberculosis who were managed with one-stage internal fixation, debridement, and combined interbody and posterior fusion through a posterior-only approach115. No sinus tract formation or recurrence of tuberculosis occurred. The kyphotic angles were also decreased.
In the lumbar spine, debridement of disc infection, decompression of abscess, and cage insertion can all be performed through an all-posterior transforaminal approach. Lee et al., in a study of sixteen patients, reported that the mean lordotic angle improved from 27.8° preoperatively to 35.8° at the time of the latest follow-up116. Postoperative complications occurred in four patients, including two patients who had transient root injury. Zaveri and Mehta, in a study of fifteen patients who were managed with transforaminal debridement and interbody fusion along with posterior stabilization, reported that the mean local lordosis was corrected from 3.7° preoperatively to 5° postoperatively117. All patients had healing of disease, and there was no recurrence at the time of the latest follow-up.
Operative Treatment in Patients with Healed Tuberculosis
Although tuberculosis can be completely cured with chemotherapy, 3% to 5% of patients still have a deformity of >60° after such treatment24,118. Treatment of established kyphotic deformities can be difficult and fraught with complications. Anterior-only, combined anterior and posterior, and posterior-only procedures have been described for the correction of established deformities. Anterior-only procedures have potential advantages such as direct adequate canal decompression and good correction of the deformity but are associated with difficulties in approaching the concavity of kyphosis in patients with deformities of >60°102,103. Combined approaches involve anterior corpectomy to achieve decompression, shortening of the posterior column, posterior instrumentation, and anterior and posterior bone-grafting94,107. However, the disadvantages include the need for two surgical approaches, increased blood loss, higher rates of infection, and prolonged surgical time. Posterior osteotomy procedures for the correction of kyphotic deformities include transpedicular decancellation procedures, pedicle subtraction osteotomy, posterior vertebral column resection, and closing-opening wedge osteotomy119-123. The authors prefer a single-stage closing-opening wedge osteotomy to correct post-tubercular deformity of >60° (Fig. 7). Rajasekaran et al., in a series of seventeen patients, reported that the average kyphosis improved from 69.2° preoperatively to 32.4° postoperatively124. The authors concluded that this technique is effective for the correction of severe post-tubercular kyphosis, with the advantage of being a posterior single-stage procedure allowing for deformity correction with minimal complications.
The poor outcomes of tuberculosis of the spine in the pre-chemotherapy era have improved with the availability of anti-tubercular drugs. MRI provides diagnostic information on spinal tuberculous lesions with high sensitivity and specificity. Neurological deficit and deformity are the worst complications of spinal tuberculosis and are now detected much earlier than before. However, present-day physicians are faced with newer problems associated with tuberculosis, such as atypical clinical presentations, drug resistance, and the combination of HIV infection with tuberculosis infection. Medical treatment is the key, and surgery is indicated for selected patients, such as those with a delayed response to chemotherapy, spinal instability, and progressive or severe neurological deficit.
Source of Funding: External support (administrative support, writing assistance) for the present study was received from the Ganga Orthopaedic Research and Education Foundation. No external funds were received.
Investigation performed at the Department of Orthopaedics, Traumatology and Spine Surgery, Ganga Hospital, Coimbatore, India
Disclosure: One or more of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of an aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. In addition, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
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