Selective intradural dorsal rhizotomy for persistent radicular leg pain: a contemporary series.

BACKGROUND: Lumbar disc surgery for radicular leg pain is one of the most frequently performed spine procedures. In approximately 20% of patients poor outcome is achieved. The most complex cases have persistent leg pain without residual nerve root compression. Treatment for refractory cases is limited to medical pain management, spinal cord stimulation (SCS), and dorsal root ganglion stimulation. For the latter two, fair to good results are obtained in only 50% of patients and costs and complication rates are high. An alternative surgical procedure is selective intradural dorsal rhizotomy (SIDR). This procedure has been largely abandoned, likely due to poor historic results and readily available modern alternatives.

PURPOSE: The goal of this paper is to report our results for SIDR for persistent monoradicular leg pain without residual nerve root compression and to compare the results with those of SCS.

STUDY DESIGN: Prospectively followed case series.

PATIENT SAMPLE: Consecutive patients with persistent monoradicular leg pain without residual nerve root compression.

OUTCOME MEASURES: Visual Analogue Scale (VAS) for leg pain, Roland Disability Questionnaire, and Likert Scale for leg pain were recorded. Complications were documented and patients were asked if, in retrospect, they would undergo the procedure again.

METHODS: In Haaglanden Medical Center, SIDR was performed on eight consecutive patients with persistent monoradicular leg pain without residual nerve root compression between December 2013 and September 2017. Patients were followed prospectively and VAS for leg pain, Roland Disability Questionnaire (RDQ), and Likert Scale for leg pain were recorded at intake, 8 weeks and 1 year after surgery and yearly after that. Minimal clinically important differences (MCID) for VAS and RDQ were predefined. Means and ranges were calculated and due to the small sample size further analysis was limited to descriptive analysis.

RESULTS: Mean follow-up was 20 months. VAS for leg pain improved from 80mm at intake to 34mm at latest follow-up. Five out of eight patients (63%) had good Likert Scale outcome (complete or near complete recovery of leg pain). Patients scored 19, 5 on the RDQ at intake and 12, 7 at the end of follow-up. Four patients (57%) reached a MCID for VAS at 1 year post surgery and one reached borderline MCID. Five patients (71%) reached a MCID for RDQ at 1 year post surgery. Six patients (75%) would undergo the procedure again.

CONCLUSIONS: SIDR is a safe and effective procedure in strictly selected patients with persistent monoradicular leg pain without residual nerve root compression. Considering the high costs and complication rates of SCS, the results of this study warrant a randomized controlled trial comparing the cost-effectiveness of SIDR and SCS.