Use of newly developed instruments and endoscopes: full-endoscopic resection of lumbar disc herniations via the interlaminar and lateral transforaminal approach

In an in vitro experiment using fresh human lumbar functional spinal units, the effects of the division of the posterior ligaments (consisting of the supraspinous/interspinous ligaments) and graded facetectomies were investigated. The graded facetectomies consisted of unilateral and bilateral medial facetectomies, and unilateral and bilateral total facetectomies. Six kinds of moments were applied and ranges of motion (ROM) and neutral zones (NZ) were determined three-dimensionally by stereophotogrammetric methods. Range of motion was not affected by the division of the supraspinous/interspinous ligaments for all load modes. In flexion, ROM increased slightly after unilateral medial facetectomy. In right axial rotation, ROM increased after left unilateral total facetectomy. Range of motion was not affected, even by bilateral total facetectomies, in extension and lateral bendings. This study suggested that medial facetectomy does not affect lumbar spinal stability, and conversely, total facetectomy, even created unilaterally, makes the lumbar spine unstable.

A retrospective study of 43 consecutive patients who underwent percutaneous endoscopic lumbar discectomy for recurrent disc herniation. To evaluate the efficacy of endoscopic discectomy for recurrent disc herniations and to determine the prognostic factors affecting surgical outcome. Repeated open discectomy with or without fusion has been the most common procedure for a recurrent lumbar disc herniation. There have been no reports published on the feasibility and prognostic factors of the endoscopic discectomy for recurrent disc herniation. The inclusion criteria were recurrent disc herniations at the same level, regardless of side, with a pain-free interval longer than 6 months after the conventional open discectomy. Posterolateral endoscopic laser-assisted disc excisions were performed under local anesthesia. The mean follow-up period was 31 months (24-39 months). Based on the MacNab criteria, 81.4% showed excellent or good outcomes. The mean visual analog scale decreased from 8.72 +/- 1.20 to 2.58 +/- 1.55 (P <0.0001). In our series, better outcomes were obtained in patients younger than 40 years (P = 0.035), patients with duration of symptoms of less than 3 months (P = 0.028), and patients without concurrent lateral recess stenosis (P = 0.007). Percutaneous endoscopic lumbar discectomy is effective for recurrent disc herniation in selected cases. The posterolateral approach through unscarred virgin tissue can prevent nerve injury and could preserve the spinal stability. Both foraminal and intracanalicular portions can be decompressed simultaneously.