Standard open microdiscectomy versus minimal access trocar microdiscectomy: results of a prospective randomized study

Minimal access surgery as a less invasive alternative to standard macro- and microsurgical approaches is becoming increasingly popular in the management of traumatic and degenerative spine diseases. However, data is lacking if minimal access spine surgery is indeed beneficial. This prospective randomized study was conducted to compare efficiency, safety, and outcome of standard open microsurgical discectomy (SOMD) for lumbar disc herniation with microsurgical discectomy using an 11.5 mm trocar system for minimal access to the spine.

Sixty patients were randomized to two groups of 30 patients each. Group 1 was treated by SOMD, and Group 2 was treated by minimal access microsurgical discectomy (MAMD). Perioperative parameters and pre- and postoperative clinical findings including sensory or motor deficits and pain according to the visual analog scale, Oswestry Disability Index scores, and Short Form-36 results were assessed. All patients were followed for at least 6 months postoperatively (mean, 16 mo).

Preoperatively, no statistically significant intergroup differences could be detected proving the comparability of both groups. Postoperatively, significant improvement of neurological symptoms and pain as measured by the visual analog scale, Oswestry Disability Index, and Short Form-36 scores could be achieved in both groups. In regard to operative time, intraoperative blood loss, and complication rate, slightly better results were observed in the MAMD group.

SOMD and MAMD allow achievement of significant improvement of pain and neurological deficits in patients with lumbar disc herniations. Differences in operative time, blood loss, and complication rates were statistically not significant in MAMD compared with SOMD, indicating that, at least in lumbar disc surgery, minimal access trocar techniques are a viable alternative to standard spinal approaches.