Objective: To collect the radiological data of the presacral space for axial lumbosacral interbody fusion (AxiaLIF) and to provide theoretic rationales for research work and clinical application of AxiaLIF in China.
Methods: The distance between inner margin of bilateral anterior sacral foramina at the level of S1 was measured radiographically. The distance between iliac vessels and the midline at the level of S1 was measured on enhanced computed tomography (enhanced-CT). The minimum distances between mesorectum and each sacral level or the center of each sacral vertebra were measured on the median sagittal plane of magnetic resonance imaging in order to measure the lengths of relevant instrumentation and fusion device.
Results: The distance between inner margin of bilateral anterior sacral foramina at the level of S1 was found to be 34.7 + or - 3.5 and 32.2 + or - 3.0 mm in Chinese males and females respectively (P < 0.05). There was no statistical significance between the design lengths of sleeve and fusion device. The nearest vessel from sacral intervertebral space at the level of S1 was found to be the bilateral internal iliac vein on enhanced-CT with a distance of 57.6 + or - 5.2 and 70.0 + or - 9.1 mm in males and females respectively (P < 0.05). The distance from mesorectum to the center of vertebral body of S2-S5 was found to be statistically significant between males and females (P < 0.05).
Conclusion: It is feasible to design suitable instrumentation and fusion device for the Chinese. And a safe operating zone has been designated.