Full Endoscopic Lumbar Discectomy using the Calcification Floating Technique for Symptomatic Partially Calcified Lumbar Herniated Nucleus Pulposus

BACKGROUND: Partially calcified lumbar herniated nucleus pulposus (HNP) can cause severe radiating pain and neurologic symptoms requiring surgical treatment. As it is not safe to enforce conventional endoscopic lumbar discectomy using trephine or burr to remove the partially calcified disc, we report a calcification floating technique using a working channel for the treatment of these cases. METHODS: We retrospectively analyzed 31 patients who underwent full endoscopic discectomy using this technique for partially calcified lumbar HNP between April 2009 and June 2013. Calcification floating technique was performed by inserting the working channel around the partially calcified HNP and then rotating the working channel around it to remove the lesion. We analyzed the outcomes with a Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and complication rate. RESULTS: The mean follow-up period was 26.58 +/- 11.2 months. The inter-laminar approach was used in 15 cases, and the transforaminal approach was used in 16 cases. The mean VAS of 8.19 +/- 0.65 before surgery was decreased to 1.29 +/- 0.69 at the last follow-up. The mean ODI score before surgery was decreased at the last follow-up, from 41.32 +/- 2.87 to 9.87 +/- 3.47. Mean operative duration was 45 +/- 12 minutes per level. None of the patients required revision surgery or developed any major complication. CONCLUSIONS: Calcification floating technique is a safe and effective method for the treatment of partially calcified lumbar HNP.