Posterior pedicle screw fixation combined with anterior single segment fusion reconstruction of unstable Denis type B thoracolumbar burst fractures

Abstract

Objective To compare the clinical effects of posterior pedicle screw fixation combined with anterior monosegmental or bisegmental fusion reconstruction in patients with unstable Denis type B thoracolumbar burst fractures. Methods A retrospective case-control analysis was made on 62 cases of Denis type B thoracolumbar burst fractures treated from June 2010 to June 2014. There were 51 males and 11 females, aged 19-55 years (mean, 35.1 years). The injury causes included fall from height in 32 cases, traffic accidents in 24, hit by heavy objects in 6. Fifty cases were with monosegmental burst fractures, and 12 with monosegmental burst fractures combined with other vertebral compressive fractures. The burst fracture levels were at T11in 8 cases, T12in 20, L1 in 24, L2 in 6, and L3 in 4. According to the different surgical methods, the patients were divided into two groups: Group A (n=30, treated with posterior pedicle screw fixation combined with anterior monosegmental fusion reconstruction) and Group B (n=30, treated with posterior pedicle screw fixation combined with anterior bisegmental fusion construction). The operation time and intraoperative blood loss were compared between the two groups. Visual analogue scale (VAS), Oswestry disability index (ODI), and Frankel scale of neurologic function were compared at last follow-up. The changes of anterior height of fracture vertebrae and Cobb angle of the two groups were also compared preoperatively, postoperatively and at last follow-up. Implant looseness and breakage, titanium mesh tilt, and bone fusion were recorded postoperatively. Results All patients were followed up for 18-24 months (mean, 20.8 months). The operation time and blood loss in Group A was (208.2±15.6)min and (598.3±55.3)ml, respectively. The operative time and blood loss in Group B was (260.1±17.4)min and (662.2±58.3)ml, respectively. There were significantly statistical differences between two groups in operation time and blood loss (P 0.05). At the final follow-up, VAS in Group A was (2.5±0.8)points, less than (3.2±1.1)points in Group B (P<0.05); ODI in Group A was (20.3±5.8)points, less than (28.2±5.1)points in Group B (P<0.05). Frankel scale was improved to some degree after operation (P<0.05). One case did not achieve bone fusion in Group A versus three cases in Group B (P<0.05). No implant loosening, titanium mesh tilt or settlement was found in Group A, while there were eight cases of titanium mesh tilt or settlement in Group B (P<0.05). Conclusions For unstable Denis type B thoracolumbar burst fractures, posterior pedicular fixation combined with anterior monosegmental fusion or bisegmental fusion can achieve equal clinical effects. However, posterior pedicular fixation combined with anterior monosegmental fusion can have less injury, higher bone fusion rate, better function restoration, and less incidence of complication. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Fracture fixation, internal