Analysis of the correlation between cerebrospinal fluid space and outcomes of anterior controllable antedisplacement and fusion for cervical myelopathy due to ossification of the posterior longitudinal ligament.

PURPOSE: To investigate whether cerebrospinal fluid (CSF) space on MRI correlates with the outcomes of anterior controllable antedisplacement and fusion (ACAF) for ossification of the posterior longitudinal ligament (OPLL).

METHODS: Fifty-three patients with OPLL who underwent ACAF were enrolled. Japanese Orthopaedic Association (JOA) score, Visual Analog Scale (VAS), and the Neck Disability Index (NDI) were used to evaluate the clinical outcomes. The area of CSF space and spinal cord on T2-weighted MRI, the occupying rate (OR) of CSF space and spinal cord, and postoperative MRI score of the CSF space were measured. Patients were divided into two groups according to the improvement rate (IR) of JOA. The relationship between postoperative MRI score and the IR of JOA was analyzed.

RESULTS: Patients in group A had better recovery than in group B regarding JOA, VAS, and NDI score at the final follow-up. On both axial and sagittal T2-weighed MRI, patients in group A had lower improvement of the area of the spinal cord than in group B (p>0.05). However, the mean improvement of CSF space in group A was better than in group B (62.86±30.05 mm2 vs -6.36±24.58 mm2 , p<0.05), with higher OR of CSF space in group A at the final visit. Strong correlation was noted between IR of JOA and postoperative CSF space score (p<0.01).

CONCLUSION: The results suggested ACAF could provide good decompression of spinal cord and neurological improvement, and the recovery of CSF space correlated closely the surgical outcomes by ACAF for cervical myelopathy due to OPLL.