Multiple factor analysis of prognosis in lumbar disc herniation

ABSTRACT

Over the years it has been found that multiple factors may influence the surgical outcome for lumbar disc hemiation. There are various series available studying the role of clinical factors in outcome, however, it may be that a multitude of patient related and clinico radiological factors may help predict a better outcome. A prospective analysis of 97 cases operated during the past 10 years was made excluding those with previous back surgery, with osseous stenosis and those operated on an emergency basis. A set of 17 independent factors related to patient particulars and clinico radiological parameters were included and outcome was analyzed in their relation. Multivariate analysis was done to form an outcome prediction model based on the analyzed factors. Modified Stauffer-Coventry criteria was used to assess outcome and it was found that for multivariate analysis factors found suitable were presence of backache and radicular pain, positive family history, hypertension, disc degeneration grade, crossed straight leg raising [CSLR] test and duration of symptoms. It was found on applying logistic regression using stepwise forward selection, a 97.5% correct predictability of good outcome and 75% correct predictability of poor outcome was obtained with an overall correct predictability of 93.8% with this model. All the factors showed a negative correlating value except the duration of symptoms. The mean follow-up was 47.96 + 28.52 [12 - 116] months. Accurate estimation of outcome may be possible using the standard patient related and clinico radiological parameters. Using them in combination, an outcome prediction model can be formulated which can help in prognosticating patients. The spectrum of patients may vary significantly in different series; however, if multiple factors are considered together, the prognosis can be predicted with reasonable accuracy. The prolonged duration of symptoms have a positive influence on prognosis whereas the presence of backache, hypertension, radicular pain, positive family history, CSLR and degeneration of disc had a negative influence on outcome: