Anterior Concave Fusion with Tibial Strut Grafts for Severe Kyphoscoliotic Deformities

Purpose: To evaluate the value of the concave approach in anterior fusions performed with tibial strut grafts in a palissade fashion for the treatment of severe kyphoscoliotic deformities.

Methods: 36 patients (mean age 13 years 3 months) with severe kyphoscoliosis underwent anterior fusion from the concavity with tibial strut grafting in a palissade fashion and posterior fusion with or without instrumentation. The etiologies of the spinal deformities were neurofibromatosis (7), various dysplastic conditions (10), congenital (11), post laminectomies (4) and miscellaneous (4). Five patients had a nonunion after a previous attempt at spinal fusion (posterior and anterior convex). Five patients presented with a progressive paraparesis. Preoperative correction of the deformity was performed in 17 patients by progressive controlled elongation in a Stagnara elongation cast.

Results: Mean follow-up was 4.9 years (2-10.9). Blood loss during the anterior approach represented on average 30% of the estimated blood volume. Fusion was achieved in all cases. Mean loss of correction was less than 3° in both frontal and sagittal plane. Four out of the five patients with a preoperative neurologic deficit were improved. Complications included one complete postoperative paraplegia, two superficial infections and two deep infections. There was one donor site tibia fracture.

Conclusions: Anterior concave approach allows to prop the whole kyphosis and to place the grafts in the ideal biomechanical situation in both sagittal and frontal plane. In that way the grafts undergo compressive forces which enhance fusion. We have the feeling that this anterior support allowed us to obtain a solid fusion in all cases, especially those with preoperative nonunion. We recommend to perform anterior concave approach for tibial strut grafting in severe kyphoscoliotic deformities with structural basic weakness of the bone.