Long-term disability assessment after surgical treatment of low grade spondylolisthesis

The aim of this study was to determine whether assessment of back surgery with disability scores is relevant. We also attempted to answer the question of whether this evaluation should be conducted by a surgeon or a medical doctor. This retrospective study analyzes the long-term outcome (average follow-up 7 years, range: 3-12) of 40 patients (mean age: 46.2 years) treated by posterior surgical decompression, posterolateral arthrodesis, with or without instrumentation, for symptomatic low-grade spondylolisthesis. All patients were interviewed postoperatively and examined the same day by an orthopedic surgeon, who was not involved in the patients' treatment, as well as by a medical doctor rehabilitation specialist. Impairment was assessed by a standardized clinical examination and by visual analog scales (VAS) of pain. Disability was assessed using two scales: the Quebec disability scale and the Beaujon scale. Anxiety and depression were assessed with a validated specific questionnaire (HAD). Patient's perceived handicap was assessed on a 100-mm VAS. Our results show that the scores of the two disability scales were highly correlated with the patient's overall satisfaction ( r = 0.73 and 0.77 for the Quebec scale and the Beaujon scale, respectively). The intraclass correlation coefficient showed very good or excellent correlation between the data collected by the surgeon and the rehabilitation specialist, ranging from 0.8 to 0.97. This finding clearly demonstrates that interview by a surgeon who is not involved in the patient's treatment does not influence the patient's assessment in terms of impairment, disability, or handicap. Moreover, our results suggest that disability scales are the most relevant outcome measures in the assessment of spine surgery.