Hybridized Inside-Out/Outside-In Approach for Treatment of Endstage Vacuum Degenerative Lumbar Disc Disease

Commonly employed transforaminal decompression techniques may use the “inside-out” and “outside-in” technique, not as a standalone technique, but as a combined technique that considers different surgical philosophies. The inside-out technique calls for an initial emphasis on visualization of the intradiscal cavity with the endoscope by advancing the working cannula inside the lumbar intervertebral disc for intradiscal examination when appropriate. In contrast, the outside-in approach places it initially into the neuroforamen and lateral recess. The authors present an illustrative case series of 411 patients in whom they employed a hybridization of these two techniques because they found it to be more reliable in cases of end-stage degenerative vacuum disc disease. The study group consisted of 192 (46.7%) females and 219 (53.3%) males with an average age of 54.84 ± 16.32. The average follow-up of 43.2 ± 26.53 months. Patients underwent surgery for herniated disc (135/411;32.8%), foraminal spinal stenosis (101/411;24.6%), a combination of the latter two conditions (162/411;39.4%), or low-grade spondylolisthesis (13/411;3.2%). Results of our clinical series showed a significant reduction of preoperative ODI and VAS for leg pain of 49.8 ± 17.65, and 7.9 ± 1.55 to postoperatively 12.2 ± 9.34, and 2.41 ±5 1.55 at final follow-up (p 0.0001), respectively. Macnab outcomes were Excellent in 134 (32.6%), Good in 228 (55.5%), Fair in 40 (9.7%), and Poor in 9 (2.2%) patients, respectively. There was end-stage degenerative vacuum disc disease in 304 (74%) of the 411 patients; 37.5% had Excellent and 50% Good Macnab outcomes.

Patients without vacuum discs had Excellent and Good 18.7% and 71.% of the time. With our hybridized technique, patients with end-stage degenerative vacuum disc disease did very well with the endoscopic decompression procedure. Improved clinical outcomes may be obtained with the direct visualization of pain generators in the epidural- and intradiscal space. It is the authors’ preferred transforaminal decompression technique

Keywords: Clinical outcomes, Inside-out, Outside-In, Transforaminal endoscopy