Evaluating 5-year outcomes of interlaminar devices as an adjunct to decompression for symptomatic lumbar spinal stenosis.

PURPOSE: To assess and compare 5-year outcomes following uninstrumented spinal decompression and decompression with interlaminar device (ILD). To determine whether improvement in clinical outcomes correlated with changes in the radiological indices studied. This is because comparative literature between the above two procedures is limited past the 2-year timeframe.

METHODS

We conducted a retrospective review of prospectively collected data from a single surgeon across 116-patients who underwent spinal decompression with or without ILD insertion between 2007 and 2015. Patients with symptomatic LSS who met the study criteria were offered spinal decompression with ILD insertion. Patients who accepted ILD were placed in the D + ILD group (n = 61); while those opting for decompression alone were placed in the DA group (n = 55). Clinical outcomes were assessed preoperatively and up to 5-years postoperatively using the ODI, Eq. 5d, VAS back and leg pain, and SF-36. Radiological indices were assessed preoperatively and up to 5-years postoperatively.

RESULTS

Both groups showed statistically significant (p < 0.001) improvement in all clinical outcome indicators at all timepoints as compared to their preoperative status. The D + ILD group achieved significant improvement in radiological parameters namely foraminal height and posterior disc height in the immediate postoperative period that was maintained while the DA group did not.

CONCLUSION

Our study found that in the management of LSS, clinical outcomes between those patients undergoing decompression alone compared to decompression with ILD showed statistically significant improvement in VAS back pain and radiological parameters namely foraminal height and posterior disc height at the 5-year mark. ILD does not predispose to increased reoperation rates.