Objective:

The upper facet joint en bloc resection is the key step to open the intervertebral foramina for achieving the intervertebral fusion in transforaminal lumbar interbody fusion (TLIF) surgery. Our purpose is to introduce a upper facet joint resection technique which can avoid injuring the nerve root termed “two layers and two tunnels strategy” in TLIF surgery and to evaluate its clinical effects and neurological safety.

Methods:

All 108 patients who underwent TLIF surgery using two layers and two tunnels strategy between December 2015 and January 2019 were analyzed for postoperative clinical treatment parameter. The visual analogue scale (VAS) method, Oswestry disability index (ODI), Japanese Orthopaedic Association (JOA) scores and the Macnab scoring system were used to evaluate the clinical effects during post-operative check-ups at 7 days, 3 months, 6 months, and the last follow-up visit. Data were represented by mean and standard deviation, and repeated measures analysis of variance was performed to make comparison.

Results:

The result noted that, the VAS scores for back pain decreased by 30.13% at 7 days post-operation (3.64 ± 0.86), 63.15% at 3 months (1.92 ± 0.55), 72.17% at 6 months (1.45 ± 0.61) and 70.44% at the last follow-up (1.54 ± 0.62) compared with pre-operation (5.21 ± 0.93). The VAS scores for lower limb pain decreased by 44.22% at 7 days (3.86 ± 0.90), 61.42% at 3 months (2.67 ± 0.72), 66.62% at 6 months (2.31 ± 0.79) and 66.47% at the last follow-up (2.32 ± 0.72) compared with pre-operation (6.92 ± 1.04). The ODI scores decreased by 49.08% at 7 days (32.19 ± 5.13), 67.92% at 3 months (20.28 ± 5.50), 74.00% at 6 months (16.44 ± 4.21) and 75.42% at the last follow-up (15.54 ± 3.85) compared with pre-operation (63.22 ± 7.58). The JOA scores increased by 51.41% at 7 days (18.49 ± 1.48), 69.26% at 3 months (22.35 ± 1.44), 73.28% at 6 months (23.22 ± 1.18) and 77.53% at the last follow-up (24.14 ± 0.99) compared with pre-operation (7.37 ± 1.71). Among 108 cases, there is no neurological complications.

Conclusion:

Two layers and two tunnels strategy is an effective and safe procedure that can certainly avoid nerve root injury to reduce neurological complication and increase safety of TLIF surgery.