GRADUAL REDUCTION USING EXTERNAL FIXATEUR FOLLOWED BY CIRCUMFERENTIAL FUSION. A SAFE AND EFFECTIVE TECHNIQUE FOR TREATMENT OF HIGH-GRADE SPONDYLOLISTHESIS.

Abstract

Background: Treatment of high-grade spondylolisthesis remains controversial. In-situ fusion does not address the sagital balance, reduction and fusion on the other hand is associated with unacceptably high rate of neurological complications.

Aim: To describe the results of a novel technique using Magerl External Fixateur for gradual reduction followed by circumferential fusion.

Methods: From 1988 to 2006, thirteen patients were treated with this technique at our institution. They all had high grade spondylolisthesis. Retrospective case note review and radiographic analysis were carried out. 10 point Visual Analogue Sore (VAS) for pain, Oswestry Disability Index (ODI), Low Back Outcome Score (LBOS), SF-36 Health Survey, and Patient Satisfaction Questionnaire were collected. Complete set of data was available for 9 patients, 7 Female and 2 Male. Mean age at operation was 16 years (range 12–22), and average length of follow-up was 11 years (range 5–19)

Results: Post operatively, Percentage of Slip was improved by an average of 70%(range 32–96%)(p=0.001), Slip Angle by 72%(p=0.0001) and sacral Inclination by 59%(p=0.0016). Radiological fusion was achieved in all but one. VAS for leg and back pain improved from 8.4 (range 8–9) and 8.2 (range 6–10) to 0.8(range 0–2) and 1.2 (range 0–2) respectively. These improvements were statistically significant (p< 0.001). ODI at the latest follow-up averaged 8% (range 0–16%) and LBOS 56.6 (range 44–70). The mean SF-36 for physical domains was 87.5 (range 80–93) and that for the psychological domains was 91.25 (range 81–100). All patients were fully satisfied. 3 cases had culture negative excessive discharge from one pin site. 2 patients developed transient parasthesia and one patient developed asymptomatic pseudoarthrosis.

Conclusion: Our technique albeit in a small cohort of patients, achieved significant correction of the commonly used and widely accepted radiological measurements without any neurological complications. The radiological improvement was also reflected in statistically significant improvement in validated outcome measures.