Monosegmental transpedicular fixation for selected patients with thoracolumbar burst fractures

Abstract

Study design: A prospective cohort study on selected consecutive patients.

Objective: To evaluate the efficacy of an innovative operative technique called monosegmental transpedicular fixation for the treatment of some thoracolumbar burst fractures.

Summary of background data: Short-segment pedicle screw instrumentation is accepted by many spinal surgeons as an acceptable technique for the treatment of thoracolumbar burst fractures. Preoperative evaluation using the spinal load-sharing makes this technique more reliable. To preserve more motion segments, some authors have advocated using monosegmental pedicle screw instrumentation (MSPI) to treat thoracolumbar fractures. However, up until now this kind of maneuver is only performed in cases of flexion distraction injuries.

Methods: A cohort of 20 patients with thoracolumbar burst fractures fulfilling the inclusion criteria were prospectively submitted to surgical treatment of monosegmental transpedicular fixation plus posterior fusion. All instrumentations were performed with pedicle screws inserted bilaterally into the fractured level and 1 adjacent level, either superior or inferior depending on the locating side of the intact endplate. All patients were followed up. The preoperative radiographs, the postoperative radiographs within 1 week of operation, and the radiographs of the most recent follow-up were evaluated for kyphosis correction recorded in the Sagittal Index and Load-Sharing Classification (LSC) index. The postoperative functional outcomes were evaluated using the Frankel Performance Scale together with the Denis Pain Scale.

Results: Eighteen patients were followed up successfully with an average final follow-up of 24.7+/-8.0 months. The focal kyphotic angulations were corrected satisfactorily with the mean Sagittal Index of preoperative 16.5+/-6.6 degrees, initial postoperative 4.0+/-2.4 degrees, and latest follow-up 4.8+/-4.0 degrees. No obvious loss of correction occurred except for 2 patients who both scored 8 points on the LSC Score. Postoperatively, most patients attained both functional neurologic improvement and pain relief, and only a few complications were noted.

Conclusions: For selected thoracolumbar burst fractures, MSPI can provide the same or better fixation and preserve more motion segments than other methods of posterior pedicle instrumentation. With preoperative evaluation using the spinal LSC system, MSPI is effective and reliable for the treatment of thoracolumbar burst fractures when properly indicated.