Radiographic anatomy and clinical significance of percutaneous endoscopic transforaminal oblique fixation from posterior corner in lumbar spine

Background Endoscopic transforaminal decompression and interbody fusion (ETDIF) has been widely discussed due to its advantages of less trauma, less bleeding, quick recovery, high safety, and relatively fewer complications, as well as adverse factors such as incomplete decompression, steep learning curve, low fusion rate, and high radiation risk. Furthermore, this technique requires the use of supplemental posterior pedicle-screw. Decompression, interbody fusion and percutaneous pedicle screw implantation are not completed in a single channel. Percutaneous endoscopic transforaminal oblique fixation from posterior corner in lumbar spine (PETOFPC) overcomes the above limitations. The purpose of this study is to confirm the anatomical feasibility for PETOFPC in the posterolateral transforaminal approach and to provide anatomic data for the design of new integrated fixable and fused interbody cage. Methods Sixty volunteers (22 men and 38 women) who underwent lumbar CT scans were collected and sent to the GEAW4.4 workstation. As a cohort study, the distances and angles of each path in the sagittal and axial planes were measured and analyzed statistically. Results The lengths of each path are not less than 40mm, and the longest can be up to 46mm. The paths in full-length group are about 5mm longer than that in medium group. PE (from point P to target E) path was the optimal path. The angles of each path were significantly different (P≤0.001), namely, a1 > a2 > a3, b1 > b2 > b3, and c1 < c2 < c3. Conclusions This study confirms anatomic feasibility for PETOFPC and provides anatomic data for the design of new integrated fixable and fused interbody cage. PETOFPC may be a very promising technology and have great clinical significance.