Posterior approach with Louis plates for fractures of the thoracolumbar and lumbar spine with and without neurologic deficits.

STUDY DESIGN: This is a retrospective revue of the long-term outcome of posterior Louis plate fixation for the treatment of irreducible or ligamentously unstable fractures of the thoracolumbar and lumbar spine with or without neurologic deficit.

OBJECTIVES: To determine the clinical, radiologic, and functional status of patients who underwent posterior fracture fixation with Louis plates and to evaluate the effect of instrumentation length on the construct's ability to maintain reduction of the fracture.

SUMMARY OF BACKGROUND DATA: Since the development of pedicle screw fixation described by Roy-Camille, there has been a rapid evolution in the number and complexity of systems available for posterior spinal stabilization. Along with this escalation in implant and instrument sophistication, there has been a corresponding increase in implant cost. To date, no series has been reported of the clinical, radiologic, and functional results of posterior instrumentation with semirigid Louis plates for spinal fractures.

METHODS: A retrospective review of spinal fractures from T11 to L5 treated since 1985 by posterior plate fixation showed that 56 patients (37 men and 19 women) with an average age of 34 years and a minimum follow-up of 2 years (average, 41 months) were available for review. There were 36 burst fractures, 4 Chance fractures and 16 fracture-dislocations treated. Forty-three patients had neurologic injury.

RESULTS: Before surgery, vertebral kyphosis averaged 15 degrees, improved to 5 degrees with reduction, and reached a steady 10 degrees at final follow-up. Similarly, corrected kyphosis initially averaged 12 degrees but improved to 0.5 degree with reduction, and was 10 degrees at final follow-up. Vertebral canal compromise initially averaged 50% but was reduced to 13% with surgery and 6% at 1 year. There was no significant difference between the ability of short and long constructs to maintain reduction. Eighty-eight percent of patients with neurologic injury improved at least one Frankel grade with treatment. Functional and pain evaluation by the Denis scale showed 25 patients rated P1, 25 rated P2, and 6 rated P3. Twenty-eight were rated W1, 16 were W3, and 12 were W5 at last follow-up.

CONCLUSIONS: Fractures of the thoracolumbar spine can be treated effectively with the semirigid Louis plating system. Because of its low cost and ease of insertion, the Louis system is an excellent choice for short arthrodesis and instrumentation of these fractures. Although there is some loss of reduction when compared with more rigid systems, there is no functional compromise in these patients.