BackgroundIndex level disc herniation following lumbar spinal decompression is somewhat overlooked as postoperative complication, resulting in return of symptoms. It is proposed that the combination of local instability and degenerated disc is more likely to result in disc herniation. There is no literature comparing post-decompression disc herniation rates between different techniques. This study compares the postoperative disc herniation rates of the "mini-open" laminectomy versus the tubular system decompression.MethodsIn a retrospective comparative study, 563 patient files who underwent primary lumbar spinal decompression, were reviewed and divided into two groups, distinguished by surgical technique. Demographic, clinical, and postoperative data were collected and compared using independent two-tailed t-test and Fisher's exact test with significance set at p<0.05. Primary outcome: comparison of post-decompression surgery, index level, disc herniation occurrence between two surgical techniques.ResultsPostoperative index level disc herniation was significantly lower in the minimally invasive surgery group with 2 cases (0.8%) versus 19 cases (5.8%) in the "mini-open" group [p=0.002]. Disc herniation following single level and multi-level operations were also significantly lower in the minimally invasive group compared with the "mini-open" group (2 versus 11 and 0 versus 8 respectively; p<0.05).ConclusionPostoperative index level disc herniation following lumbar spinal decompression occurs in 3.7% of surgeries. Minimally invasive surgery is found to result in less herniations then "mini-open".