Objective
To investigate the clinical efficacy of anterior thoracic lesion removal and internal fixation of bone grafting in the treatment of high grade thoracic and thoracolumbar spinal union.
Methods
Thoracic anterior lesion removal with internal fixation of bone graft was used to treat 35 patients of advanced age with thoracic and thoracolumbar spinal tuberculosis, which were treated with regular protocol after surgery.
Results
After 12~36 months of follow-up, all 35 patients in this group had normal healing of the incision, partial fusion of the bone graft for 6~12 months, and fusion by the time of the last follow-up, with significant improvement of the kyphosis deformity, no recurrence of the lesion, and no displacement of the titanium mesh or loosening of the internal fixation.
Conclusion
The clinical efficacy of internal fixation with bone graft removal from anterior thoracic lesions for the treatment of spinal tuberculosis in the senior thoracic and thoracolumbar segments is good, with good fusion rate of bone graft and reliable fixation.
1. Materials and methods
1.1 Case data were selected from May 2009 to January 2012. 35 patients with advanced thoracic spine and thoracolumbar spinal tuberculosis were admitted to our hospital, including 19 males and 16 females, aged 61-77 years (average 68.4 years). All of them were treated by anterior thoracic lesion removal and internal fixation with bone grafting. After admission, all patients underwent X-ray, CT and MRI examinations and clarified the lesion segments, as well as blood sedimentation, C-reactive protein, liver and kidney function examinations. Comprehensive preoperative imaging results: T4-T78 cases, T8-T1010 cases, T11-L212 cases, L2-L45 cases.
1.2 Preoperative preparation Patients with confirmed diagnosis were given regular quadruple anti-tuberculosis treatment (isoniazid 0.4g, rifampin 0.45g, ethambutol 0.75g, streptomycin 0.75g, pyrazinamide for streptomycin allergy) and systemic nutritional support therapy 3-4 weeks before surgery [3]. Surgery was performed after the patients’ symptoms of tuberculosis toxicity improved, hemoglobin reached more than 100 g/L, plasma protein amount was normal, hematocrit was <40 mm/h or had a significant decreasing trend and their general condition was good. The preoperative neurological function was graded by Frankel [4], and there were 9 cases of grade B, 15 cases of grade C and 11 cases of grade D among 35 patients in this group.
1.3 The surgical method used was endotracheal intubation with general anesthesia, and different surgical accesses were used according to the patient’s lesion site. Patients with thoracic spinal tuberculosis had a transthoracic approach; patients with thoracolumbar tuberculosis had a combined extrapleural peritoneal incision or a combined thoracic extraperitoneal approach. The spinal canal is then accessed through a combined thoracic and lumbar approach. The spinal canal is then decompressed, part of the vertebral body of the more heavily compressed segment is removed, and the necrotic intervertebral disc is cleared; for those whose MRI suggests pus below the posterior longitudinal ligament, part of the posterior longitudinal ligament is carefully removed to achieve adequate decompression. After the removal of the anterior lesion, a large amount of saline was used to flush the operative field. The titanium mesh was selected according to the size and height of the bone defect, and the resected ribs were made into rod-shaped bone graft strips as intervertebral bone graft material and implanted into the titanium mesh. The upper and lower normal vertebral bodies were propped up to correct the posterior convexity deformity, and the titanium mesh with bone graft strips was placed between the vertebral bodies for support. A vertebral screw of appropriate length is placed laterally and anteriorly to the upper and lower normal vertebrae. An anterior vertebral fixation device is installed and locked with appropriate pressure. Streptomycin 2g (or isoniazid 0.2g) is dissolved in 1L of warm saline and the surgical field is flushed with 2L of saline. Streptomycin 2 g (or isoniazid 0.2 g) was spread into the TB lesion area, the fixation was carefully covered, a closed chest drain was placed, and the surgical incision was closed according to the anatomical level [3,5,6].
1.4 Postoperative treatment Dehydration, infection prevention, symptomatic treatment, intravenous drip and oral anti-tuberculosis drugs were given postoperatively. Routinely check all vital signs of patients and closely observe the closed chest drainage and lung opening. 24h closed chest drainage and remove the drainage tube when the chest X-ray indicates good lung opening. Postoperatively, liver and kidney function, blood sedimentation and blood routine were reviewed monthly, and imaging examinations (X-ray, CT examination and MRI) were performed regularly. Quadruple anti-tuberculosis treatment with isoniazid, rifampin, ethambutol and streptomycin was applied for 9 to 12 months of continuous treatment. The time of going down to the ground was decided according to the stability of the patient’s internal fixation, and the brace was worn to protect the activity for more than 3 months.
2.Results
All 35 senior patients were followed up for 12 to 36 months after discharge. The partial fusion of the implants took 6 to 12 months, and all of them were fused at the last follow-up, and the kyphosis of the thoracic spine and thoracolumbar segment was significantly corrected. There was no recurrence of the lesion, no displacement of the titanium mesh and no loosening or fracture of the internal fixation. The erythrocyte sedimentation rate decreased to normal within 2 months after surgery, and there were no significant abnormalities in liver and kidney function during the anti-tuberculosis treatment. The recovery of neurological function (Franke1 classification) 1 year after surgery: 9 cases of grade B recovered to grade C in 2 cases, 4 cases of grade D and 3 cases of grade E; 15 cases of grade C recovered to grade D in 9 cases and 6 cases of grade E; 11 cases of grade D recovered to grade E in 9 cases and 2 cases did not recover.
3. Discussion
Spinal tuberculosis is a common orthopedic disease, accounting for about half of bone and joint tuberculosis, with lumbar tuberculosis being the most common, followed by thoracolumbar segment, thoracic spine, sacral spine, and cervical spine in that order [6]. The spine consists of an anterior-middle and posterior column, with the compression side in the anterior-middle column and the tension side in the posterior column, with the anterior intervertebral internal fixation acting as the main support band and the posterior internal fixation acting as the main tension band. Therefore, anterior lesion-removal implant internal fixation is more in line with the principle of biomechanical fixation and has been commonly used [7]. In our group of 35 elderly patients, all of them were fixed with anterior lesion-removing implants via the thoracic cavity, and the fixation was reliable, with high fusion rate of the implants, no displacement of the titanium mesh and loosening of the internal fixation, and significant improvement of the kyphosis with no recurrence of the lesions.
3.1 Surgical indications
Indications for surgery for spinal tuberculosis include paravertebral abscesses, dead bone, sinus tracts, neurological symptoms, spinal deformities, failure of nonoperative treatment, and irreversible or persistently worsening pain while on standardized antituberculosis drugs [8]. The most important treatment for thoracic spinal tuberculosis is antituberculous drug therapy, which should follow the principles of early, regular, appropriate, combined, and full course. The aim of surgery is to decompress the spinal cord, stabilize the spine, correct the posterior convexity deformity, and prevent aggravation of the deformity [9]. If tuberculous pus, case-like necrotic material, tuberculous granulation tissue, or dead bone protrudes into the spinal canal and compresses the spinal cord and cauda equina nerve, neurological damage can occur. While neurological damage is the most serious complication of the disease, early surgical decompression should be performed to avoid irreversible neurological dysfunction on the basis of aggressive anti-tuberculosis drug therapy [5,10].
3.2 Surgical access
At present, the main surgical approaches for the treatment of spinal tuberculosis are: transanterior lesion removal, intervertebral body graft fusion and anterior internal fixation; trans-posterior lesion removal and posterior internal fixation; trans-posterior internal fixation with anterior resection and intervertebral body graft fusion. The main goal of surgical treatment of the disease is to completely remove the tuberculous lesions, reduce spinal cord compression, and at the same time prevent or correct kyphosis and re-establish the stability of the spine [6]. Among them, the transthoracic approach technique is chosen to ensure normal ventilation of both lungs, minimize the impact of surgery on pulmonary function, and provide a clear surgical view for complete removal of the lesion. In addition, transthoracic or transthoracic or extraperitoneal surgical access has the following advantages: complete removal of the lesion; direct observation of the dura mater, reducing nerve injury; keeping the posterior column intact and not introducing the lesion into the normal posterior column, etc [3].