Segmental square spinal instrumentation for posterior lumbar spinal fixation

The purpose of this study is to evaluate the clinical results of operations using a new spinal instrumentation for posterior fixation, called segmental square spinal (3-S) instrumentation. The 3-S instrument consists of two pairs of hooks to clasp the interarticular portion of the lamina bilaterally, two horizontal bars to connect the hooks on the right and left, and rods to connect the hooks side by side on the top and bottom. Twenty-seven patients who had degenerative lumbar disorders underwent operations with the 3-S instrument. Rigid fixation was obtained in all cases immediately after the operation. Bone union rates were 91% (21/23) with posterolateral fusion. The 3-S instrument seems to be suitable for spinal disorders in which anterior spinal fusion is not necessary, especially for degenerative spinal disorders.