Background: Microsurgery of foraminal and extraforaminal disc herniation at the L5-S1 level remains a challenge because of the limited access by a high iliac crest, the sacral ala, large transverse processes of L5 and hidden disc fragments lateral to the zygapophyseal joint. Our aim was to present the outcome of percutaneous endoscopic lumbar discectomy (PELD) of these lateral and far lateral disc herniations at the L5-S1 level using the newly described foraminal retreat technique in a group of patients with similar preoperative diagnostic studies.
Methods: A total of 22 patients, 13 males and 9 females, with foraminal and extraforaminal lumbar disc herniation at the L5-S1 level were treated by applying the PELD between September 2004 and April 2010. The clinical findings and MRI were the main diagnostic methods. Preoperative evaluation was performed with clinical examinations, the Visual Analog Pain Scale (VAS) and Oswestry Low Back Disability Index (ODI).
Findings: According to the Macnab criteria, overall excellent or good outcomes were obtained in 18 patients (81.8 %), fair outcomes in 3 patients (13.6 %) and a poor outcome in 1 patient (4.5 %) at the last follow-up. The mean ODI was 67.3 ± 19.4 preoperatively and 26.7 ± 23.4 postoperatively. Preoperative VAS was 88.6 ± 7.6 and 28.6 ± 22.8 at 2 days, 40.5 ± 22.8 at 3 weeks, 34.3 ± 25.1 at 6-months and 32 at the last follow-up. At follow-up, two patients (9.1 %) had recurrent disc herniations that were corrected with open surgery. At the time of surgery, 16 patients held jobs. Fifteen (15) patients (93.8 %) returned to their original jobs postoperatively; one patient could not return to his original job postoperatively because of a comorbidity.
Conclusions: Percutaneous endoscopic discectomy using the foraminal retreat technique is an effective treatment method for patients with foraminal and extraforaminal disc herniations at the L5-S1 level on appropriately selected patients.