Comparative Study of Graf Stabilization and Posterior Fusion in the Treatment of Chronic Symptomatic Mechanically Unstable Low Back Syndrome

Abstract

Spinal stabilization of unstable intervertebral segments is a well recognized technique in the management of patients with chronic pain with or without neural compression in an attempt to relieve the patient's symptoms. The introduction of internal fixation techniques using a variety of different materials began at the early part of this century and there has been a significant expansion of such techniques over the past 20 years. There is significant controversy between treating spinal surgeons as to whether such stabilization techniques should involve semi-rigid or totally rigid systems. Henry Graf in 1988 introduced a new concept in spinal stabilization utilizing dacron bands between pedicle implants as opposed to the previously available systems which used a solid plate or rod to interconnect the intervertebral fixation devices (pedicle screw, wires, sub laminar hooks). This paper will report the results of a independently reviewed prospective study comparing patients who have undergone the Graf procedure and either a rigid plate fixation or spinal fusion without fixation. The patients were equally matched for age, sex and psychological parameters (Zung and Somatic Indices). The results demonstrated a much better functional outcome in those patients who underwent the Graf procedure. This was using rigid criteria introduced by Greenough and Fraser (Low Back Outcome Score). There was no significant difference with respect to patients' satisfaction in the case of Graf and patients undergoing spinal fusion without internal fixation. Those patients who underwent rigid spinal fixation did not report as good patient satisfaction as the other two groups. The psychological indices both pre- and postoperative for the three groups were similar. The complications between all groups were also similar and not statistically significant. This study would suggest that the Graf Soft Stabilization Technique does offer patients a potentially better functional outcome than the more rigid systems, though further prospective studies are necessary given the number of variables.