Reduction of high-grade spondylolisthesis using minimally invasive spine surgery-transforaminal lumbar interbody fusion "trial-in-situ" technique: a technical note with case series

Abstract

This retrospective case series evaluated the effectiveness of minimally invasive spine surgery-transforaminal lumbar interbody fusion (MIS-TLIF) using the "trial-in-situ " technique for reducing high-grade spondylolisthesis. The surgical management of grade ≥III spondylolisthesis has been controversial, with various methods documented in the literature, including in-situ fusion, in-situ trans-sacral delta fixation, distraction techniques, and external reduction techniques. Recently, MIS techniques have gained popularity. This study analyzed 18 cases of high-grade spondylolisthesis treated with MIS-TLIF using the "trial-in-situ " technique. The clinical outcomes were assessed using the Visual Analog Scale (VAS) and the modified Oswestry Disability Index (mODI) scores. The spinopelvic parameters and sagittal balance were also analyzed. Preoperatively, the spinopelvic parameters were deranged, with a mean pelvic tilt of 28.31°, which improved to 13.91° postoperatively. Similarly, the sacral slope improved from 45.65° to 38.01°. VAS and mODI scores improved postoperatively, indicating the effectiveness of the "trial-in-situ " technique in reducing high-grade spondylolisthesis and achieving a better sagittal profile and spinopelvic parameters. The findings indicate that MIS-TLIF using the "trial-in-situ " technique is a viable and effective method for treating high-grade spondylolisthesis.

Keywords: Intervertebral disc displacement; Minimally invasive surgical procedures; Radiculopathy; Spinal fusion; Spinal stenosis; Spondylolisthesis; Transforaminal lumbar interbody fusion.

Fig. 1

Showing ‘trial-in-situ’ (blue handle) on contralateral side (A). After distraction by ‘trial,’ ipsilateral screwhead attachments or towers showing indirectly the amount of spondylolisthesis remaining (B). After tightening distal screw first (S1 in this case) followed by L5–cantilevering effect, both the screw-head attachments/towers are at same levels, indicating no listhesis remaining (C).

Fig. 2

Showing a nice and sharp medial trajectory of pedicle screws with bi-cortical and tri-cortical purchase of L5, S1 (A, B). Postoperative incision length (C).

Fig. 3

Pictorial diagram showing ‘near complete reduction’ with cage first technique (A). With trial-in-situ technique, because of smooth surface resulting into a ‘complete reduction’ with the help of cantilevering mechanism (B).

Fig. 4

Sagittal X-ray showing severely abnormal sagittal balance and spinopelvic parameters at L4–L5 levels (A, B). Non-contrast computed tomography lumbo-sacral spine showing dramatically improved parameters (C). TK, thoracic kyphosis; SAA, sagittal acetabular anteversion; LL, lumbar lordosis; SS, sacral slope; PT, pelvic tilt; PI, pelvic incidence; PI–LL, pelvic incidence minus lumbar lordosis; tLL, target lumbar lordosis; tPT, target pelvic tilt.

Fig. 5

High-grade spondylolisthesis at L5–S1 with abnormal preoperative sagittal balance and pelvic parameters (A). Postoperative X-ray and non-contrast computed tomography lumbo-sacral spine showing a ‘complete reduction’ and improved spinopelvic parameters at L5–S1 (B, C). LL, lumbar lordosis; SS, sacral slope; PT, pelvic tilt; PI, pelvic incidence; PI, pelvic incidence.