ABSTRACT
Trans-sacral canal plasty (TSCP) is a minimally invasive lumbar spine surgery under local anaesthesia. TSCP is expected to be effective regardless of whether the patient has had previous surgery. However, there are cases in which open revision surgery is required after TSCP. This study aimed to identify risk factors for open revision surgery after TSCP in order to determine surgical indications and limitations. A retrospective case-control study was conducted in patients who underwent TSCP for lumbar spine disease. Data of 112 patients were analysed. During an observation period of 7-23 months, 34 patients (30.4%) required open revision surgery and 78 (69.6%) did not. The following patient background characteristics were investigated: age, sex, body mass index (BMI), diagnosis, history of spine surgery and the institution where the surgery was performed. Comorbidities were scored using the Elixhauser Comorbidity Index. Preoperative imaging parameters were investigated, including the lesion level (L4/5, L5/S1, other), presence of intervertebral instability, dural sac area, presence of bony stenosis and presence of epidural lipoma. Multivariate analysis revealed that intervertebral instability (odds ratio 2.56, confidence interval 1.00-6.51, p = 0.046) and a narrow dural sac area (odds ratio 0.98, confidence interval 0.97-0.99, p = 0.002) were significant risk factors for open revision surgery after TSCP.
ABSTRACT
RATIONALE: A cervical pedicle screw (CPS) serves as an important anchor for cervical surgeries. Its placement requires the development of a highly safe and easy-to-handle method. Considering that the lateral end of the cortical bone of the spinal canal (LE point) is the most crucial for CPS placement, we devised a U-shaped wire capable of identifying LE points under direct vision and reliably confirming the site with C-arm lateral fluoroscopy. PATIENT CONCERNS: A 65-year-old male, who had been aware of numbness in both hands, mild finger dexterity disorder, and gait disturbance for half a year, visited our hospital due to the progression of his symptoms in the previous 2 months. DIAGNOSIS: The patient presented with mild muscle weakness and tendon hyperreflexia in the upper and lower extremities on both sides, and magnetic resonance imaging revealed moderate spinal canal stenosis at the C4/5 and 5/6 levels. Based on the local third cervical vertebra (C3)/4 angle of -10 degrees and the C2/7 angle of -15 degrees, the patient was diagnosed with cervical myelopathy with cervical kyphosis. He had a Japanese Orthopaedic Association score for cervical myelopathy of 10. INTERVENTIONS: We placed CPSs at C3 using a U-shaped wire. After placing an anchor in the range of C3-T1, laminectomy from C4 to C7 was performed. Subsequently, corrective fixation was performed to reduce kyphosis, followed by bone grafting in the range of C3-T1 and complete posterior cervical decompression fixation. OUTCOMES: The CPSs were placed at C3 without deviation and intra- or postoperative complications. The surgery resulted in improvement in kyphosis with a C2/7 angle of -5 degrees and recovery in spinal cord disorder with a Japanese Orthopedic Association score for cervical myelopathy of 13. LESSONS: A U-shaped wire, which can be prepared inexpensively and easily, is a useful tool, especially for inexperienced surgeons, for safe CPS placement by capture of LE points accurately.
