Transpars Microscopic Approach for the Treatment of Purely Foraminal Herniated Lumbar Disc: A Clinical, Radiological, Two-center Study

Study Design. This is a prospective two-center study. Objective. The aim of this study was to assess the safety and efficacy of treating patients with lumbar foraminal disc herniations via a microscopic transpars approach, with a clinical and radiological follow-up evaluation. Summary of Background Data. Purely foraminal lumbar disc herniations comprise about 5% of all lumbar herniated intervertebral discs. Operative management can be technically difficult, and the optimum surgical treatment remains controversial. Methods. From January 2012 to January 2015, 47 patients were prospectively recruited. Patients were followed-up as outpatients at 1 week after discharge, then at 1, 6, and 12 months. A clinical multiparametric evaluation of patients including numeric rating scale (NRS), drugs intake, Macnab criteria, and working days lost was used. Postoperative dynamic x-rays (flexion, extension) were performed in all cases 12 months after surgery. Results. No surgery-related complications occurred. Among the 35 patients who were not retired at the time of the study, 29 patients returned to work and to normal daily activities within 60 days after surgery. Pain evaluation at discharge showed a significant improvement of NRS score, from 8.93 to 1.45 at 12 months. Root palsy significantly improved in all cases already at 1-month follow-up. Drugs intake analysis showed that at 6-month follow-up, no patients used steroids, or opioids, 17 patients used non-steroidal anti-inflammatory drugs when needed, and 29 patients (61.7%) used no drugs for pain relief. No significant variations occurred at 12-month-follow-up. At 12-month follow-up, excellent or good outcome (following Macnab criteria) was achieved in 36 (76.6%) and 8 (17%) patients, respectively. There were no cases of spinal instability at 12-month radiological evaluation. No recurrence occurred at follow-up. Conclusion. Transpars microscopic approach is effective and safe for the treatment of FLDH, but larger studies are needed.