Treatment of Denis type B thoracolumbar burst fractures by anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach

Abstract

Objective To evaluate the clinical efficacy of anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach in the treatment of Denis type B thoracolumbar burst fractures. Methods A retrospective case series study was made on 26 cases (14 males and 12 females, mean age of 48.5 years) of Denis type B thoracolumbar burst fractures treated by anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach from January 2007 to June 2009. Age was 18-68 years (mean, 48.5 years). The fractured vertebrae included T1 in three cases, L1 in 18 and L2 in five. The neurological status was Grade C in eight cases, Grade D in 12 cases and Grade E in six cases according to American Spinal Injury Association (ASIA) classification. The operation duration, blood loss and incision length were recorded. The neurological function, lower back pain were evaluated by visual analogue score (VAS), correction of kyphosis and restoration of the fractured vertebral body height followed and documented at 3, 6 and 9 months and annually after surgery. The healing of the graft was assessed using Brantigan method based on 3-dimensional computed tomography at final follow-up. Results All patients were successfully managed with this approach. The operation duration was (214.6±30.5)min, and the intraoperative blood loss was (389.7±57.1)ml. The length of incision was (8.5±1.3)cm. All patients were followed up for (6.3±0.4)years. At final follow-up, the neurological functions of all patients with incomplete neurological deficit were improved for at least one grade. The VAS of lower back pain was improved from preoperative (7.8±1.6)points to (2.1±0.8)points at final follow-up (P<0.05). The height of the intervertebral body was restored from preoperative (29.8±5.3)mm to(35.2±2.4)mm at final follow-up (P<0.05). The kyphosis was corrected from preoperative (20.4±11.7)° to (11.3±5.5)° at final follow-up (P<0.05). Bone fusion was achieved in all patients, with no looseness, breakage or displacement of internal fixation at follow-up. Conclusions Anterior single segmental decompression and instrumentation through Endoring self-support retractor-assisted minimally invasive small incision approach can reduce the surgical trauma, achieve complete spinal canal decompression, adjust kyphosis, fix segment, obtain high rate of bone graft fusion and hence is a safe and effective method with minimal invasion for Denis type B thoracolumbar burst fractures. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Fracture fixation, internal