Evaluation of Two Methods (Inside-Out/Outside-In) Inferior Articular Process Resection for Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion: Technical Note

Abstract

Objective: There is limited literature comparing the uniportal full endoscopic posterolateral transforaminal lumbar interbody fusion outside-in approach (ETLIF (O)) with the inside-out approach (ETLIF (I)). Methods: Radiological evaluation was performed on disc height restoration and coronal wedging angle, and operation time (inferior articular process resection time/total operation time) and clinical evaluation were made. Result: 48 cases of inside-out and 38 cases of outside-in cases were included. Compared to inside-out, the outside-in approach had significantly less operative time required to resect inferior articular process: 36.55 ± 10.37, and total operative time: 87.45 ± 20.14 min compared to 49.83 ± 23.97 and 102.56 ± 36.53 min, respectively, for the inside-out approach, p < 0.05. Compared to the preoperative state, both cohorts achieved significant improvement of VAS and ODI at post-operative 1 week, 3 months and at final follow up. Both cohorts achieved statistically significant increased disc height with 5.00 ± 2.87 mm, 5.49 ± 2.33 mm and statistically significant improvement in coronal wedge angle with 1.76 ± 1.63°, 3.24 ± 2.92° in the inside-out and outside-in approaches respectively. Conclusions: Complete removal of inferior articular process is the key part of endoscopic fusion with two methods that can be applied: an inside-out approach or an outside-in approach. Comparing both techniques, the outside-in approach has a shorter operative time required for inferior articular process resection and total length of operation with similar good clinical and radiological outcomes.

Prospective Cohort Study with a 2-Year Follow-up of Clinical Results, Fusion Rate, and Muscle Bulk for Uniportal Full Endoscopic Posterolateral Transforaminal Lumbar Interbody Fusion

“…endoscopic fusion using a larger diameter uniportal stenosis endoscope. There was no fusion data and muscle cross-sectional area evaluation in these studies [12][13][14]. We found that there was sustained improvement in pain and function with VAS, ODI, and MacNab's criteria in this study while the complications were minor with no implant-related revision or adjacent segment disease at 2 years after index operation.…”

“…EPTLIF is an alternative posterolateral approach to the traditional Trans-Kambin approach in uniportal endoscopic fusion and was used in this cohort study. It was previously described by Kim et al [ 12 , 13 , 18 ] and Wu et al [ 14 , 19 ]. Surgery was performed on a Wilson Frame over a radiolucent table, and the patient was under general anesthesia.…”

“…A posterolateral approach was first performed as a biportal endoscopic-assisted posterolateral lumbar interbody fusion [9,10]. Kim et al [11][12][13] and Wu et al [14] published several reports on uniportal endoscopic posterolateral transforaminal lumbar interbody fusion (EPTLIF) applications on various degenerative conditions using large diameter stenosis endoscope. Psoas and paraspinal muscle cross-sectional area is correlated to lower back pain [15,16].…”

Comparative Cohort Study Of Paraspinal Muscle Volume Change Between Uniportal Full Endoscopic And Minimamally Invasive Open Posterolateral Transforaminal Lumbar Interbody Fusion

“…17,46 3) Uniportal full endoscopic posterolateral route transforaminal interbody fusion using a similar approach to biportal endoscopic interbody fusion, the facets were resected and harvested as bone graft and a large interbody cage was inserted after disc preparation with the aid of large stenosis endoscope. 19,20,22 The advantage of endoscopic fusion with full facet resection is that large interbody cage can better stabilize the anterior column of lumbar spine as a load sharing device, this helps to promote fusion and prevents implants failure due to reversed bending movement generated if there is insu cient anterior column support. 47 In our Endo-TLIF cohort we used the technique of uniportal full endoscopic posterolateral route transforaminal interbody fusion which allowed large cages used in MIS-TLIF to be inserted in our patients who underwent Endo-TLIF.…”

“…Soft tissue dissection done with radiofrequency ablator, isthmus and inferior articular process is exposed and bony drilling is done on the isthmus and inferior articular process for inferior articular facetectomy which is harvested as bone graft. 22 Superior articular facet is drilled under endoscopic guidance and harvested as bone graft. We subsequently remove ligamentum avum and expose the ipsilateral disc space and the traversing and exiting nerve root.…”