KumaFix fixation for thoracolumbar burst fractures: a prospective study on selective consecutive patients

Short-segment U-shaped pedicle screw fixation has been widely used to treat thoracolumbar burst fracture. Some studies have reported the disadvantages of traditional U-shaped pedicle screw, which included a relatively high rate of adjacent segment degeneration and screw failure, including screw pullout and breakage. The purpose of this study was to assess the efficacy of open reduction and fixation using KumaFix fixation system in treatment of thoracolumbar burst fractures.

From June 2011 to June 2012, 45 consecutive patients with thoracolumbar burst fractures were enrolled. They were randomly assigned to treatment with KumaFix (the treatment group, n = 23) or traditional U-shaped pedicle screw (the control group, n = 22). The patients were followed up postoperatively and were assessed with regard to radiologic and clinical outcomes. Radiologic outcomes were assessed mainly on the basis of Cobb angle and vertebral wedge angle. Clinical outcomes were evaluated mainly with use of Visual Analog Scale (VAS) for pain and the Oswestry Disability Index (ODI) Questionnaire.

All patients were followed up from 9 to 22 months. There were no significant differences between the two groups with regard to preoperative indices. The operation time in the treatment group was significantly lower than that in the control group. Preoperative Cobb angles and vertebral wedge angles in two groups were significantly decreased after surgery, and these have been well maintained at the last follow-up with mild correction losses. The results of clinical outcome showed lower VAS and ODI scores in two groups compared with those preoperative, and the treatment group had greater improvement on the ODI compared with the control group at the last follow-up.

Compared with traditional U-shaped pedicle screw, KumaFix fixation system can achieve gradual, controlled reduction, provide enough space for bone implantation, and avoid acceleration of adjacent segment degeneration. It is an effective and reliable technique to treat thoracolumbar burst fractures.