2nd and 3rd generation full endoscopic lumbar spine surgery: clinical safety and learning curve

2nd and 3rd generation endoscopic spine surgery techniques offer visualisation of familiar inter-laminar anatomy to spinal surgeons. We have prospectively evaluated the clinical outcome, complications and learning curve associated with these techniques in patients with lumbar spine radiculopathy.

This is a prospective study of 50 consecutive patients with radicular pain from disc herniation and/or lateral recess stenosis. In 6 patients, endoscopy couldn't be done. Operating times, PROM's (VAS, ODI and EQ-5D scores) and complication rates of 44 patients were evaluated after mean FU of 52 months (range 39-65). MRI was used to divide these into protrusions (n = 19), extrusions (n = 17) and lateral recess stenosis (n = 8). Evidence about the learning curve was gathered by curvilinear regression analyses.

Using a composite clinical success criterion, 95% patients had a successful outcome, with no major complications. ODI, VAS and EQ-5D scores had a statistically significant improvement and achieved MCID. Revision discectomy rate was only 4.5% (n = 2). MRI based grouping, case sequence and degree of difficulty influenced the duration of surgery and a learning curve was found for protrusions and lateral recess decompressions, but not for extrusions. A learning curve effect was also observed with respect to the ODI.

Although anatomy visualised in 2nd and 3rd generation endoscopy is familiar to spinal surgeons, our learning curve experience suggests a careful and MRI pathology based take up of this technique in clinical practice, despite its clinical safety in our series.

Level 3, prospective cohort study.