Study design:

Prospective cohort study.

Objective:

To report reoperation rates after lumbar tubular microdecompression (LTM) and to compare patient-reported outcomes (PROs) six years after surgery between those who did and did not need revision at the index level.

Summary of background data:

Long-term data describing PROs and reoperation rates after LTMs are lacking.

Materials and methods:

Patients with lumbar spinal stenosis underwent one or more of three LTM procedures. Demographic, PROs [Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain], and reoperation data were collected. Failure of an index LTM was defined as any revision surgery at the index level. Revision LTM at a different level was not considered failure. Failure and revision LTM incidence at a different level and cumulative incidence were prospectively collected up to six years. Mixed effects linear regressions with 95% CIs were performed to assess potential differences in ODI and reported VAS back and leg pain between patients that reported failure and those that did not.

Results:

A total of 418 patients were included with median follow-up of 3.0 (1.9, 4.1) years. In all, 25% had a reoperation by six years. Sixty-five (16%) failed and 35 (9%) underwent a second LTM at another level. Cumulative failure incidence was 9% within the first two years. Failure patients had a statistically higher ODI [12.1 (95% CI, 3.2, 20.1) and VAS back [2.3 (95% CI, 0.9, 3.8)] and leg pain [1.6 (95% CI, 0.2, 3.1)] throughout follow-up. The overall dural tear rate was 7.2%.

Conclusions:

LTM is an effective treatment for lumbar spinal stenosis with sustained six-year PROs. Most failures occur within two years postoperatively and stabilize to 4% yearly incidence by year 5. The yearly incidence of reoperation with LTM stabilizes at 3% by year 6 postoperatively.

Level of evidence:

2.