Surgical indications in low lumbar burst fractures: experiences with Anterior Locking Plate System and the reduction-fixation system.
A study of 14 surgically treated patients with low lumbar burst fractures (L3 to L5) is reported. Initially, 13 patients presented with incomplete neurologic deficits below the level of injury. The follow-up period ranged from 24 to 40 months, with an average of 30 months. In group 1, seven patients underwent one-stage anterior decompression, fusion, and Anterior Locking Plate System (ALPS) fixation. In Group 2, seven patients had posterior surgery with decompression, portero-lateral fusion, and a short segment fixation, one above and one below the injuried level, with the reduction-fixation transpediculate system. Indications for one-stage anterior surgery consisted of patients with incomplete neurologic deficits, segmental kyphotic deformity caused by loss of anterior vertebral height (< 50%), or canal encroachment < 50%. When there is significant radiologic evidence of lamina fractures, displaced or greenstick type, or injuries that occurred at the L5 level, the posterior approach was undertaken initially. This may be followed by anterior surgery if satisfactory vertebral height restoration or canal clearance was not achieved. Five dura tears (36%) were noted during surgery: two tears in group 1 and three tears in group 2. There were two patients in group 2 (29%) who had screws broken; however, none in group 1 demonstrated implant failure. In the low lumbar region, the step-off ALPS plate is preferable to the straight plate because of the increasing size of the vertebral body toward the caudal area. A low profile and easy application were its advantages. However, the ALPS could not be distracted or compressed anteriorly.