FAILED BACK SURGERY SYNDROME: CONTRIBUTION OF ASSOCIATING SPINAL CORD NEUROSTIMULATION AND POSTERIOR SPINAL RESTABILISATION IN A SINGLE PROCEDURE

Abstract

Purpose: Eary results of a prospective study of a homogeneous group of 45 patients treated by electrical stimulation of the posterior cords for refractory chronic pain subsequent to postoperative fibrosis demonstrated good results (function and pain relief) in 77% of patients with a mean follow-up of 51 months. We further examined the technique treating certain cases of post-surgical refractory chronic lumbar radiculaglia using spinal cord neurostimulation and posterior spinal restabilisation during the same procedure.

Material and methods: Results of a small series of eight patients, mean age 48 years were examined at a mean follow-up of 11 years. Five of the patients were manual labourers and five were occupational accident victims. All had a history of endocanal surgery (narrow lumbar canal, disc hernia). These eight patients had lumbar and radicular pain which were chronic and refractory to conservative treatment. The usual preoperative tests were: percutaneous epidural neurostimulation for radiculalgia by deafferentation and immobilisation test with a corset for lumbalgia. Chronic neurostimulation of the posterior cords was indicated if either test was positive. Metronic ITREL II or III was used. Posterior restabilisation was performed by arthrodesis with a posteriolateral graft, or for more recent patients, by dynamic lumbar neutralisation (Dynesys). Neurostimulation and posterior stabilisation were performed during the same operative procedure.

Results: This therapeutic association enabled four of the patients to resume their occupational activities. Two patients were retired. Radiculalgia: At last follow-up, antalgic effect of neurostimulation persisted for six patients. For one, radiculalgia recurred at eight years. For the last patient, despite rigorous preoperative selection, pain recurred early at two years. Lumbalgia: Improvement persisted at last follow-up in four of the eight patients. Lumbalgia recurred in three at eight to eleven years. This time corresponds to the usual duration of arthrodesis efficacy due to the development of a neo-junction, the reason for which we extened our indications for dynamic neutralisation. The last patient developed a neojunction at two years and underwent extension of the arthrodesis with good antalgesia at ten years.

Conclusion: Combining electrical stimulation and spinal restabilisation in the same procedure provides a real antalgesic effect for certain patients with postoperative lumboradicular pain. The quality of the results are less favourable for lumbalgia because the effect of the arthrodesis is less long-lasting. It is hoped that the new Synergy electrode, with promising effect on radiculalgia and lumbalgia and which is currently under evaluation, will meet its expectations.