Sagittal alignment to predict efficiency in pulsed radiofrequency for cervical facet joint pain

Neck pain due to cervical facet joint pain has a prevalence of 36-60% in chronic neck pain. Pulsed radiofrequency for such pain has been verified. After proper patient selection, pulsed radiofrequency of the cervical facet joints provide long-term pain relief in a routine clinical setting. In the patient selection, clinical and sagittal alignment parameters are rarely discussed for the outcome. In the present study, we analyzed the factors from the clinical data and sagittal alignment parameters and investigated the associated predictors of pulsed radiofrequency for cervical facet joint pain. There were 204 patients with cervical facet joint pain who received a medial branch block and pulsed radiofrequency between 2015 and 2020 after excluding patients with neurological symptoms and other confounding factors. The patients were classified into good and poor outcome groups based on the improvement of the pain score(visual analog scale). Clinical and radiological data were analyzed. Multivariable logistic model showed that the predictors were cervical lordosis including two methods (odds ratio [OR] 0.92, 95% confidence interval [CI]: 0.89-0.96 for C2-C7 Cobb angle; OR 0.91, 95% CI: 0.88-0.95 for the angle measured by the Jackson method), ossification of the nuchal ligament, number of diseased facet joints, anterior cervical discectomy with fusion, and adjacent facet joint after anterior cervical discectomy with fusion. With the results, we demonstrated that the outcome were related to cervical lordosis including two methods, formation of ossification of nuchal ligament, the number of diseased facet joints, post anterior cervical discectomy with fusion, and adjacent facet joint post anterior cervical discectomy with fusion. The corresponding optimal cutoff for discriminating a poor outcome was 7° for the C2-C7 Cobb angle and - 2° for the angle measured using the Jackson method.