Abstract
Background
Endoscopic spine lumbar interbody fusion (Endo-LIF) is well-regarded within the academic community. However, it presents challenges such as intraoperative disorientation, high rates of nerve damage, a steep learning curve, and prolonged surgical times, often during the creation of the operative channel. Researchers have developed new techniques to enhance the efficiency of establishing the operative channel. However, these often lack robust anatomical data support. Furthermore, the undefined safe operational zones under endoscopy continue to pose risks to surgical safety.
Objective
This study analyzes the anatomical data of Kambin’s triangle via CT imaging to define the parameters of the safe operating area for Transforaminal Posterior Lumbar Interbody Fusion (TPLIF), providing crucial insights for clinical practice.
Methods
Identify the clearest coronal plane at the L4-L5 intervertebral space for examining the exiting and traversing nerve roots, and observe Kambin’s triangle along with the inscribed circle. Record the position of point “J” on the adjacent facet joint as the center “O” of the circle shifts by angle “β”. Measure the diameter of the inscribed circle “d” (mm), the abduction angle “β” (°), and the distances “L1” and “L2” (mm) from the trephine’s edge to the exiting and traversing nerve roots, respectively.
Results
In a dataset of 40 cases, the diameter of the inscribed circle 'd' measured 11.62 mm (11.35, 12.04), significantly exceeding the 8 mm diameter of the visible trephine (P < 0.001). The angle 'β' was 32.02° (± 0.90). The 'J' point, acting as the safe center, was consistently located in the outer upper quadrant of the demarcated facet joint (P < 0.001). Safe distances 'L1' and 'L2' measured 1.40 mm (1.34, 1.43) and 2.30 mm (2.14, 2.34), respectively, indicating that using an 8 mm diameter visible trephine would not damage the exiting or traversing nerve roots.
Conclusions
CT imaging studies conducted by the author's team have defined the safe operational area for TPLIF, offering effective clinical references. This is expected to reduce the learning curve, decrease surgery durations, and improve surgical safety.