AO fixateur interne in treating burst fractures of the thoracolumbar spine

A burst fracture of the thoracolumbar junction is an unstable spinal fracture, which is caused by high-energy trauma. There are many methods of treatment, both surgical and nonsurgical, in dealing with spinal burst fractures. The Arbeitsgemeinschaft für Osteosynthesefragen (AO) Fixateur Interne (FI) system was introduced in 1985 for posterior spine surgery with a transpedicular screw system.From April, 1989, through December, 1994, we encountered 42 patients with 42 acute burst fractures of the spine; 26 were male and 16 were female, with an average age of 41.2 years. One fracture occurred on T11, seven on T12, 16 on L1, 11 on L2, one on L3, four on L4 and two on L5. According to the Denis classification, there were eight type A, 23 type B, five type C, three type D and three type E fractures. All of these patients received posterior reduction without decompression, posterior short segmental fixation with AO FI instrumentation and posterior fusion.After follow-up for an average of 66.1 months, all fractures were found to have united with residual back pain in only six patients; five patients, including one with nonunion, had back pain without the necessity of medication, and the other one had occasional back pain that was well controlled by medication. The immediate postoperative Cobb's angle improved by an average of 14.2 degrees, and there was an average loss of 3.3 degrees at final follow-up. All patients were neurologically intact at final follow-up except two patients, who were Frankel D. Seven patients had complications during follow-up; one experienced nonunion; four experienced screw breakage, one had screw pullout, and the other experienced breakage of the connecting rod.From our retrospective study, the outcome of burst fracture of the spine treated with AO FI instrumentation system was satisfactory.