TRANSPEDICULAR GRAFT WITH POSTERIOR INSTRUMENTATION FOR LUMBAR AND THORACOLUMBAR FRACTURES: A SERIES OF 11 CASES

Abstract

Purpose: This prospective study was conducted to evaluate correction of post-traumatic deformity of the thoracolumbar and lumbar spine at consolidation after posterior instrumentation associated with transpedicular graft.

Material and method: The analysis began in 1998 and included 11 patients (mean age 37 years, age range 19–62 years) with lumbar (two L2) or thoracolumbar (four T12 and five L1) fractures. The Magerl classification was A1=2, A2=3, mixed=3. Inclusion criteria were: age < 65 years, regional kyphosis > 10°), intact pedicles, relative gain on local and/or regional kyphosis peroperatively > 70% after correction for reduction-distraction. Posterior instrumentation used the V-V assembly in two cases and 2VV-1VC assembly in nine. Evaluation criteria were, postoperatively and at consolidation: local kyphosis, corrected regional kyphosis, Cobb angle in the frontal plane. Autologous graft tissue harvested from the iliac crest was introduced via the right and left pedicle into the damaged vertebra using an adapted funnel after raising the vertebral plate with a spatula.

Results: Mean follow-up was 11 months (range 8–18). Associated procedures were laminectomy in three cases and posterior graft in two. Preoperatively local kyphosis was 19° (12° to 37°) and regional kyphosis was 17° (10° to 35°). Postoperatively, local and regional kyphosis were 4.5° (0–11°) and −2° (−10 to 5°) giving a mean relative gain of 80% (SD = 0.1). Mean relative gain at consolidation was 75% (SD = 0.2 for local kyphosis and 86% for regional kyphosis. The correction was statistically significant. There was no significant difference between the correction postoperatively and at consolidation.

Discussion: Transpedicular grafting associated with posterior instrumentation can avoid anterior access in a certain number of cases. Indications are fractures in patients under 65 years of age with a regional kyphosis > 10° and an important anterior defect after reduction (> 40% reduction in height). All patients achieved bone healing without significant loss of correction. The limitations of this technique include the requirement for intact pedicles, a posterior wall displacement of less than 60% and a peroperative relative gain greater than 70% for the local and/or regional kyphosis. An anterior approach must be associated in other cases.

Conclusion: Transpedicular grafting is a simple technique allowing true reconstruction of the vertebral body. It can avoid a certain number of supplementary anterior approaches.