Abstract
Background The impact of minimally invasive decompression (MID) techniques on spinopelvic parameters
and on the sagittal alignment remains a controversial topic. Here we studied the changes
in clinical and radiologic parameters and their relationships in a series of lumbar
spinal stenosis (LSS) submitted to MID with a minimum follow-up (FU) of 24 months.
Methods We prospectively collected clinical and radiologic data of 20 consecutive patients
who were evaluated preoperatively, at the 6-month FU, and at the 24-month FU. Visual
analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), neck disability
index (NDI), sagittal vertical axis (SVA), C7 slope (C7S), lumbar lordosis (LL), pelvic
incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed for each patient.
Moreover, the percentage variation of clinical and radiologic factors at the 24-month
FU compared with the preoperative factors was calculated to perform correlation studies
among these variables.
Results We reported a significant improvement of all clinical parameters. A significant increase
of LL and SS and a significant decrease of PT and SVA were observed. The preoperative
values of ODI, LL, SS, PT, and SVA significantly affect the 24-month FU values, and
the percentage improvement of SVA at the 24-month FU compared with the preoperative
values was significantly related to the percentage improvement of LL.
Conclusions MID is clinically effective in patients with LSS and improves the spinopelvic parameters
and the global sagittal balance of the spine. The preoperative spinal alignment affects
the spinal alignment at FU. The improvement of SVA was strictly related to the improvement
of LL.
Keywords sagittal balance - minimally invasive decompression - lumbar spinal stenosis - spine
surgery