Anterior decompression with single segmental spinal interbody fusion for lumbar burst fracture

Study Design. The clinical and radiologic records for seven patients with lumbar burst fracture who underwent anterior decompression with single segmental interbody fusion were reviewed. Objective. To determine the clinical results obtained with this method and its influence on the intervertebral disc degeneration inferior to the fusion. Summary of Background Data. Some patients with Denis' type B fracture can tolerate one-segment anterior fusion. However, there is no reliable information in the literature regarding the juxtafusional disc degeneration after one-segment fusion. Methods. Seven patients with type B lumbar burst fractures, including four with cleavage fracture of the lower endplate, underwent anterior single segmental fusion; three patients underwent surgery with no instrumentation, and four underwent surgery with Kaneda instrumentation. The mean follow-up period lasted 85 months. The kyphosis angle and inferior intervertebral disc height adjacent to the fusion were measured before and after surgery. Pain and working status were evaluated using the scales proposed by Denis et al. Results. Significant correction loss was obtained 1 year after surgery in the patients in whom no instrumentation was used (7.3 +/- 0.6 degrees), compared with the correction loss in patients whose surgery included the use of instrumentation (0.3 +/- 0.5 degrees; P = 0.00001). No further correction losses were seen in either group at the final follow-up examination. No marked reduction in disc height was observed in any patient, including the four patients with cleavage fracture of the lower endplate. All patients returned to their previous occupation; five patients were rated as P1 (no pain) and W1 (returned to heavy labor), and two patients were rated as P2 (minimal pain) and W2 (return to heavy labor with lifting restrictions) at the final follow-up examination. Conclusions. There was slight correction loss within 1 year when no instrumentation was used, but this deformity did not affect the clinical results. The results provided no evidence that cleavage fracture of the lower endplate accelerates degeneration of the adjacent intervertebral disc.