Novel Approach to Percutaneous Lumbar Surgeries via Kambin's Triangle-Radiographic and Surgical Planning Analysis with Nerve Segmentation Technology

OBJECTIVE: While Kambin's Triangle has become an ever more important anatomic window given its proximity to the exiting nerve root, there have been limited studies examining the effect of disease on the corridor. Our goal was to better understand how pathology can affect Kambin's Triangle, thereby altering the laterality of approach for percutaneous lumbar interbody fusion (percLIF).METHODS: The authors performed a single-center retrospective review of patients evaluated for percLIF. The areas of Kambin's Triangle were measured without and with nerve segmentation. For the latter, the lumbosacral nerve roots on 3-dimensional T2 magnetic resonance imaging were manually segmented. Next, the borders of Kambin's Triangle were delineated, ensuring no overlap between the area and nerve above.RESULTS: Fifteen patients (67.5 +/- 9.7 years, 46.7% female) were retrospectively reviewed. We measured 150 Kambin's Triangles. The mean areas from L1-S1 were 50.0 +/- 12.3 mm(2), 73.8 +/- 12.5 mm(2), 83.8 +/- 12.2 mm(2), 88.5 +/- 19.0 mm(2), and 116 +/- 29.3 mm(2), respectively. When pathology was present, the areas significantly decreased at L4-L5 (P = 0.046) and L5-S1 (P = 0.049). Higher spondylolisthesis and smaller posterior disk heights were linked with decreased areas via linear regression analysis (P < 0.05). When nerve segmentation was used, the areas were significantly smaller from L1-L5 (P < 0.05). Among 11 patients who underwent surgery, none suffered from post-operative neuropathies.CONCLUSIONS: These results illustrate the feasibility of preoperatively segmenting lumbosacral nerves and measuring Kambin's Triangle to help guide surgical planning and determine the ideal laterality of approach for percLIF.