Objective: The objective of this study was to evaluate the clinical significance of the transforaminal ligaments (TFLs) in relation to the area of the lumbar intervertebral foramen (IVF) by analyzing cadaveric spines.
Methods: One hundred ninety-eight cadaveric lumbar IVFs were studied, and the existence and type of TFLs were identified. All IVFs were photographed, and the images were saved. The areas of the IVFs and TFLs were measured with the Scion Image for Windows image analysis program.
Results: TFLs were found in 82.8% of the IVFs. The oblique inferior transforaminal ligament was the most common. The mean area of the IVFs was 155.8 +/- 51.1 mm2, and the mean area occupied by the TFLs was 46.3 +/- 37.6 mm2. The mean percentage of the IVF area occupied by the TFLs was 28.5 +/- 18.8%.
Conclusion: TFLs are common structures in the IVF and may reduce the space available for the spinal nerve root within the IVF. In this circumstance, any compromise of the IVF may impinge on the nerve root.