Study design
This is a retrospective case control study. Patients with thoracic and lumbar tuberculosis who underwent surgery at Sun Yat-sen Memorial Hospital of Sun Yat-sen University between January 2010 to June 2018 were included in the present study and were divided into anterior group and posterior group according to the different surgical approaches. Outcomes of patients in both groups were followed up. Each patient signed a consent form for data collection. And this study was approved by the Ethnic Committee of Sun Yat-sen Memorial Hospital.
Subject selection
The inclusion criteria were as follows: (1) Patients who have been diagnosed with thoracic or lumbar tuberculosis by medical history, clinical manifestations, laboratory examinations, imaging examinations, lesion tissue smears and tuberculosis bacteria culture or postoperative lesion tissue pathological examinations; (2) Patients with single lesion of thoracic or lumbar tuberculosis, and underwent simple anterior or posterior surgery; (3) The patients were completed in our hospital from the first visit to the last follow-up, and the follow-up time was more than 1 year or at least until the bone fusion occurred.
The exclusion criteria were as follows: (1) Patients whose tuberculosis lesions only invaded the cervical or sacral spine or with multiple spinal tuberculosis lesions; (2) Patients who underwent anterior and posterior combined approach surgery; (3) Patients who suffered from other diseases of the thoracic and lumbar spine that affect the clinical efficacy, such as tumors, purulent infections, ankylosing spondylitis, disc herniation, spondylolisthesis, spinal stenosis, etc.; (4) Patients with considerable loss of follow-up data, or follow-up time less than 1 year and without bone fusion.
Grouping
According to the above inclusion and exclusion criteria, a total of 52 patients with thoracic or lumbar tuberculosis were included in the study, including 29 males and 23 females, with an average age of (42.2±18.0) years old. According to different surgical approaches, they were divided into the anterior group and the posterior group. Among them, 24 patients in the anterior group (12 males and 12 females), aged 41.1±19.3 years, were followed up for an average of 27.2 (13.1-35.3) months; 28 patients in the posterior group (17 males, 11 females), aged 43.2 ±17.1 years old, were followed up for an average of 22.3 (16.2-38.0) months. The lesions of all 52 patients were located between T4 and L5/S1 intervertebral discs. We assessed the extent of lesion severity based on the number of vertebral bodies and intervertebral discs involved. There were no significant differences in gender, age, follow-up time, lesion location and lesion severity between the two groups (Table 1).
Table 1
Preoperative Patient Characteristics
|
Anterior
(n = 24)
|
posterior
(n = 28)
|
Total
(n = 52)
|
P
|
Gender
|
|
|
|
|
Male
|
12
|
17
|
29
|
0.577
|
Female
|
12
|
11
|
23
|
|
Age(Years)
|
41.1±19.3
|
43.2±17.1
|
42.2±18.0
|
0.685
|
Follow-up period (months)
|
27.2
(13.1-35.3)
|
22.3
(16.2-38.0)
|
23.2
(15.5-36.6)
|
0.964
|
Lesion location†
|
|
|
|
|
T4-T10/11
|
9
|
13
|
22
|
0.752
|
T11-L2
|
11
|
10
|
21
|
|
Below L2
|
8
|
9
|
17
|
|
Lesion severity
|
|
|
|
|
Involved vertebral body (n)
|
2.0(1.3-2.8)
|
2.0(2.0-2.0)
|
2.0(2.0-2.0)
|
0.588
|
Involved intervertebral disc (n)
|
1.0(1.0-1.8)
|
1.0(1.0-1.0)
|
1.0(1.0-1.0)
|
0.086
|
† Some lesions were involved in two lesion locations simultaneously. |
Study methods
preoperative preparation
All patients without indications of emergency surgery were routinely treated with preoperative anti-tuberculosis chemotherapy for 2-3 weeks, as well as the day of operation. The anti-tuberculosis drugs include isoniazid, rifampicin, pyrazinamide, ethambutol, and streptomycin. We used a four-drug combination anti-tuberculosis regimen including isoniazid and rifampicin (except for drug allergies or intolerances).
Surgical procedure
Anterior approach surgery: The patient was placed in lateral decubitus position after general anesthesia. Thoracoscopy, lateral thoracotomy, retroperitoneal or thoracoabdominal combined approach was used to expose the lesion. Complete debridement and sufficient decompression in front of the spinal cord were performed. The sclerotic bone or suspected necrotic bone around the lesion should be scraped and trimmed to prepare the bone graft bed. Rib or iliac bone of appropriate length was taken as bone graft. Titanium mesh was used or not depended on the degree of bone defect. Anterior single rod or double rods screw internal fixation was performed to restore spinal stability. When the bone destruction of the affected vertebrae was less than 50%, screws could be inserted; otherwise, the screws should be inserted in the adjacent vertebrae of the affected vertebrae. Once the titanium mesh was placed, the ends of the titanium mesh were required to contact with the normal bony endplate. The incision was rinsed with a large amount of normal saline, hydrogen peroxide and iodophor solution of type three in turn. Then 1.5g of streptomycin or isoniazid powder was sprinkled into the lesions. A closed thoracic drainage tube or common drainage tube was placed, and the incision was closed.
Posterior approach surgery: After general anesthesia, the patient was placed in a prone position and the lesion was located by C-arm machine. A posterior midline incision was made centered on the lesion. The skin, subcutaneous tissue and myofascia were dissected to expose the lamina and facet joints of corresponding segments, and the thoracic lesion was exposed to the transverse process and even part of the ribs. Generally, pedicle screws were inserted in 1-2 vertebral bodies above and below the lesion. When the lesion was large or the stability of the spine was poor, pedicle screws were inserted in 3 vertebral bodies above and below the lesion. Decompression by laminectomy was performed. The dural sac and nerve roots should be fully exposed. The intercostal nerves and vessels involved were ligated if necessary. Complete debridement was performed to remove tissues such as pus, granulation tissue, dead bone, and residual intervertebral disc. The sclerotic bone or suspected necrotic bone around the lesion should be scraped and trimmed to prepare the bone graft bed. The bone used for bone grafting was obtained from spinous process, lamina or articular process by posterior spinal canal decompression. If not enough, rib or iliac bone was selected. Titanium mesh was used or not depended on the degree of bone defect. If the titanium mesh was placed, the ends of the titanium mesh were required to be in contact with the normal bony endplate. The incision was rinsed with a large amount of normal saline, hydrogen peroxide and iodophor solution of type three in turn. Then 1.5g of streptomycin or isoniazid powder was sprinkled into the lesions. A closed thoracic drainage tube or common drainage tube was placed, and the incision was closed.
Postoperative treatment
The drainage tube was removed when the amount of drainage was less than 50 ml/d. The thoracic closed drainage tube was removed about 48 hours after the operation. The Standard anti-tuberculosis chemotherapy was continued, including a four-drug combination of isoniazid and rifampicin (except for drug allergies or intolerances). The course of treatment was 12-18 months, of which 3-6 months was intensification. Erythrocyte sedimentation rate (ESR) and liver function were reviewed weekly during hospitalization and monthly after discharge. Patients were followed up every 3 months postoperative, and their X-ray images were reviewed. Computerized tomography (CT) was performed when needed to further confirm the bone fusion status. After bone fusion, follow-up was done 1-2 times per year.
Statistics analysis
SPSS 22.0 (IBM, Chicago, IL, USA) was used for data analysis. In statistical description, for continuous variables that conformed to a normal distribution, the mean ± standard deviation was used; if they do not conformed to a normal distribution, the median (interquartile range) was used. The Kolmogorov-Smirnov test was used for the normality test, and the Levene test was used for the homogeneity of variance test. This study involved the comparison of two independent samples. For quantitative data, if the samples followed a normal distribution and the variances were uniform, then the analysis of variance was used. If the above conditions are not met, the rank-sum test (Kruskal-Wallis test) was used. For qualitative data, the comparison of the two groups of binary data and the comparison of the two groups of unordered multi-class data used the chi-square test or the exact probability method, while the comparison of the two groups of ordered multi-class data used the rank-sum test (Kruskal-Wallis test). A significance level of 0.05 was adopted.