Reduction of severe adolescent isthmic spondylolisthesis: a new technique.

STUDY DESIGN

The case of a 14-year-old boy with a severe-grade isthmic spondylolisthesis who underwent reduction and stabilization using this technique is described.

OBJECTIVE

To report a new sequential 3-stage procedure for reduction and stabilization of severe adolescent isthmic spondylolisthesis during 1 operative session.

SUMMARY OF BACKGROUND DATA

Conventional reduction techniques do not address the important regional anatomic restraints on the L5 nerve root during the reduction maneuver, thereby leading to a high risk of neurologic deficit. Using certain technical refinements could reduce the risk of neurologic deficit. A literature review of reduction of high-grade spondylolisthesis and details of the technique are presented.

METHODS

We describe a new 3-stage procedure in a 14-year-old boy who presented with persistent mechanical low back pain, bilateral buttock and leg pain secondary to a severe-grade L5/S1 isthmic spondylolisthesis. Radiologic investigations, including plain radiographs and computerized tomography confirmed the diagnosis. Magnetic resonance imaging showed reduction of signal intensity in the disc at the L5/S1 level. We describe the 3 stages of this technique, which can provide complete sagittal correction. The technical variations to allow a safe reduction of the spondylolisthesis are illustrated.

RESULTS

This new procedure can achieve almost complete reduction of severe grades of L5/S1 spondylolisthesis, leading to an excellent cosmetic result and also considerably reduces the risk of neurologic deficit.

CONCLUSIONS

In severe-grade lumbosacral spondylolisthesis, isolated posterior fusion, even when supplemented with internal fixation, is not sufficient to prevent deformity progression. Therefore, a combined anterior and posterior fusion is necessary. Reduction of the deformity leads to restoration of normal sagittal alignment with an excellent cosmetic result. Reduction without release of posterior structures may lead to neurologic deficit. This 3-stage shortening procedure can provide sudden reduction of deformity with minimal risk of neurologic deficit. The procedure is technically demanding, and should be performed by spinal surgeons who are familiar with the principles of anterior and posterior fusions.