[The application of ultrasonic bone curette in laminoplasty of spinal canal after resection of intraspinal tumors].

Objective: To explore the practicability and safety of ultrasonic bone curette in the laminoplasty of spinal canal after resection of intraspinal tumors.

Methods: The clinical data of 17 patients with thoracolumbar intraspinal tumors treated with ultrasonic bone curette after resection of intraspinal tumors between December 2015 and April 2017 were retrospectively analyzed. All patients were male, aged 42-73 years with an average of 57.4 years. The disease duration was 2-47 months with an average of 21.1 months. Among them, there were 4 cases of thoracic intrathoracic tumors (T 10 in 1, T 12 in 3) and 13 cases of lumbar intrathoracic tumors (L 1 in 5, L 2 in 4, L 3 in 2, and L 4 in 2). Postoperative pathological diagnosis showed that 8 cases were schwannoma, 4 cases were meningioma, 2 cases were neurofibroma, 2 cases were dermoid cyst, and 1 case was ependymoma. Spinal nerve function was evaluated preoperatively according to Frankel classification criteria, with 2 cases of grade B, 7 cases of grade C, and 8 cases of grade D. During the operation, the time of single segmental vertebral canal posterior wall incision, the overall operation time, intraoperative blood loss, intraoperative dural injury, and cerebrospinal fluid leakage, spinal cord and nerve root injury were recorded. At 3-6 months after operation, the tumor and bone healing were observed according to MRI and CT three-dimensional reconstruction, and the spinal nerve function was evaluated by Frankel classification.

Results: The time of ultrasonic osteotomy for the posterior wall of a single segmental vertebral canal was 3.4-5.7 minutes, with an average of 4.1 minutes. The overall operation time was 135-182 minutes, with an average of 157.3 minutes. The intraoperative blood loss was 300-500 mL, with an average of 342.6 mL. There was no accidental dural injury, and cerebrospinal fluid leakage, nerve root injury, or spinal cord injury. The incision healed by first intention after operation. All the 17 patients were followed up 9-18 months, with an average of 12.7 months. MRI examination showed no tumor recurrence, and CT three-dimensional reconstruction showed good bone healing in all patients. During the follow-up, there was no loosening or rupture of the internal fixator and there was no re-compression of the spinal cord. At last follow-up, according to Frankel classification, there were 1 case as grade B, 5 cases as grade C, 7 cases as grade D, and 4 cases as grade E.

Conclusion: The application of ultrasonic bone curette in laminoplasty of spinal canal after resection of intraspinal tumors can preserve the integrity of the bone ligament structure of posterior column, maintain the volume of vertebral canal, and has high safety, practicability, and good postoperative effectiveness.