Study patients
The retrospective study was approved by the ethics board committee of The First Affiliated Hospital of Fujian Medical University. In addition to this, we confirm that all methods were performed in accordance with the relevant guidelines and regulations. A total of 38 patients diagnosed with thoracolumbar spinal tuberculosis with psoas abscesses were enrolled in this retrospective study. All patients included underwent single-stage posterior-only debridement, decompression, allograft bone using titanium mesh and interbody fusion from January 2010 to September 2016. The diagnosis of thoracolumbar spinal TB was confirmed based on clinical manifestation, such as back pain, slight fever, night-sweats or weight loss; the positive laboratory results of tuberculin test and T-SPOT test, and increased levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); vertebrae destruction and psoas abscesses observed by plain films, computed tomography (CT) and magnetic resonance imaging (MRI); and sequestrum and granulation tissue observed by pathological examination. The Frankel grading system was used to evaluate the neurological function of patients. The back pain was recorded using visual analogue scale (VAS) scores. Various parameters including Cobb angle, operative time, blood loss, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and postoperative complications were used to evaluate the clinical effectiveness of the surgery.
Preoperative care
Patients enrolled in this retrospective study received preoperative chemotherapy of HREZ with a dosing consisted of isoniazid (H, 300 mg/d), rifampicin (R, 450 mg/d), ethambutol (E, 750 mg/d) and pyrazinamide (Z, 750 mg/d) for at least two weeks. Surgical treatment was performed when the patient got relieved typical symptoms, decreased ESR and CRP levels, and recovered hypoproteinemia.
Surgical techniques
After general endotracheal anesthesia, patients were placed in the prone position. Through posterior midline incision, the posterior tissues were exposed, centered on the diseased vertebral body and extended to one or two vertebrae upward and downward. Then transpedicular screws were installed at the mild side of vertebral pedicle based on the symptoms and imaging results. Before debridement and decompression, a temporary rod was stabilized in order to protect spinal cord from injury. The severe side of the abscess was performed with debridement of the affected vertebrae, necrotic disc and paravertebral abscess. Then, according to the range of abscess, we performed debridement through one or both pedicles. After eliminating the affected vertebrae, necrotic disc and paravertebral abscess, a flush tube was inserted in psoas abscess to wash the focus with appropriate pressure until no sanies outflow. Then, levofloxacin was used to wash the lesion again. After that, titanium mesh filled with allograft bone was used to rehabilitate spinal sequence, with a transpedicular screw and rod system to achieve the stability of spine. Lastly, streptomycin (1 g) and isoniazid (0.3 g) were placed in the operation site. To achieve improved focus debridement, two drainage tubes were inserted in the abscess cavity before the incision was closed.
Postoperative care
When the drainage volume was under 30 ml/24 hours, the drainage tubes were removed. Postoperative patients received treatments of mannitol dehydration (375 ml/day) and conventional nerve nutrition (mecobalamin, 1.5 mg/day) to reduce any postoperative edema of the incision and nerves, and to accelerate neurological recovery. Patients were encouraged to exercise their limbs in bed and were instructed to wear orthosis until the achievement of bone fusion. Anti-TB chemotherapy was continued post-operatively for patients with the same as preoperative regimen for six months, followed by another 9-12 months regimen of isoniazid, rifampicin and ethambutol. All patients underwent periodical radiological and laboratory examination at one week, and three, six, and twelve months after surgery, and annually thereafter
Statistical analysis
All measurement data were expressed as mean ± SD. The SPSS 21.0 software (IBM Corp., Armonk, NY, USA) was used for statistical analyzation. Pre- and postoperative comparisons were performed by the Paired-sample t-test, with a P value < 0.05 regarded as statistically significant.