Clinical Effects of Upper Facet Joint En Bloc Resection in the Transforaminal Lumbar Interbody Fusion Surgery-Two Layers and Two Tunnels Strategy.

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.

Enhanced Information Flow From Cerebellum to Secondary Visual Cortices Leads to Better Surgery Outcome in Degenerative Cervical Myelopathy Patients: A Stochastic Dynamic Causal Modeling Study With Functional Magnetic Resonance Imaging.

Degenerative cervical myelopathy (DCM) damages the spinal cord, resulting in long-term neurological impairment including motor and visual deficits. Given that visual feedback is crucial in guiding movements, the visual disorder may be a cause of motor deficits in patients with DCM. It has been shown that increased functional connectivity between secondary visual cortices and cerebellum, which are functionally related to the visually guided movements, was correlated with motor function in patients with DCM. One possible explanation is that the information integration between these regions was increased to compensate for impaired visual acuity in patients with DCM and resulted in better visual feedback during motor function. However, direct evidence supporting this hypothesis is lacking. To test this hypothesis and explore in more detail the information flow within the "visual-cerebellum" system, we measured the effective connectivity (EC) among the "visual-cerebellum" system via dynamic causal modeling and then tested the relationship between the EC and visual ability in patients with DCM. Furthermore, the multivariate pattern analysis was performed to detect the relationship between the pattern of EC and motor function in patients with DCM. We found (1) significant increases of the bidirectional connections between bilateral secondary visual cortices and cerebellum were observed in patients with DCM; (2) the increased self-connection of the cerebellum was positively correlated with the impaired visual acuity in patients; (3) the amplitude of effectivity from the cerebellum to secondary visual cortices was positively correlated with better visual recovery following spinal cord decompression surgery; and (4) the pattern of EC among the visual-cerebellum system could be used to predict the pre-operative motor function. In conclusion, this study provided direct evidence that the increased information integration within the "visual-cerebellum" system compensated for visual impairments, which might have importance for sustaining better motor function in patients with DCM.