Endoscopic spine surgery is a promising and minimally invasive technique for the treatment of disc herniation and spinal stenosis. However, the literature on the outcome of interlaminar endoscopic decompression (IED) versus conventional microsurgical technique (CMT) in patients with lumbar spinal stenosis is scarce. We analyzed 88 patients (IED: 36/88, 40.9%; CMT: 52/88, 59.1%) presenting with lumbar central spinal stenosis between 2018–2020. Surgery-related (operation time, complications, time to hospital release (THR), ASA score, C-reactive protein (CRP), white blood cell count (WBC), side (unilateral/bilateral), patient-reported (ODI, NRS (leg-, back pain), eQ5D, COMI), and radiological (preoperative dural sack cross-sectional area (DSCA), Shizas score (SC), left (LRH) and right (RRH) lateral recess heights, left (LFA) and right (RFA) facet angle) parameters were extracted.

Complication (most often re-stenosis due to hematoma and/or residual sensorimotor deficits) rates were higher in the endoscopic (38.9%) than microsurgical (13.5%) treatment group (p<0.01). Age, THR, SC, CRP, and DSCA revealed significant correlations with 3 weeks and 1 year postoperatively evaluated ODI, COMI, eQ5D, NRS leg, or NRS back values in our cohort. We did not observe significant differences in the endoscopic versus microsurgical group for the patient-reported outcomes.

Age, THR, SC, CRP, and DSCA revealed significant correlations with patient-centered outcomes and should be considered in future studies. Endoscopic treatment of lumbar spinal stenosis was similarly successful as the conventional microsurgical approach, although it was associated with higher complication rates in our single-center study experience. This was probably because of the surgeons' lack of experience with this method and the resulting different learning curve compared with the conventional technique.

We carried out a prospective study looking at the functional outcome and post-procedure segmental instability after lumbar decompression using a flip osteotomy technique that involved unilateral subperiosteal muscle dissection with hinging of the spinous processes thereby preserving the integrity of the posterior elements for unilateral or bilateral lumbar spine decompression.

Between February 2007 and February 2008, 51 patients (29 male and 22 female) diagnosed with degenerative and congenital lumbar stenosis with an average age of 60, underwent central and lateral canal decompression using the flip osteotomy technique. An average of two segments (range 1-3 segments) was decompressed. Patients with a history of previous spinal surgery, spinal fusion, existing degenerative spondylolisthesis or cauda equina syndrome were excluded.

All patients were followed up for a mean of 1.5 years. Five outcome measures were used – visual analogue scale for pain, Likert scale for functional status, symptom specific well-being score, general well-being score, number of days incapacitated in last 4 weeks. The outcomes measures were recorded pre-operatively, 6 weeks and one year post-operatively. Successful surgical outcome was defined as an improvement in at least four out of five outcome measures.

90% (46 patients) of patients had a successful surgical outcome. There was a statistically significant improvement in all outcome criteria (p<0.005) at the 6-week post-operative mark as compared to pre-operatively, with marginal improvement at one year post-surgery. There was no evidence of progressive lumbar segmental instability at one year post-operatively using our flip osteotomy technique

Decompression of the lumbar spine for lumbar stenosis using the flip osteotomy technique is a safe approach for one or multi-level stenosis with good outcomes and no evidence of significant iatrogenic segmental spinal instability.

We declare no conflict of interest and ethical approval was obtained