Change in morphology of intramedullary T2-weighted increased signal intensity after anterior decompressive surgery for cervical spondylotic myelopathy

摘要

STUDY DESIGN.: Retrospective study. OBJECTIVE.: To study the change in morphology of T2-weighted (T2W) increased signal intensity (ISI) and its association with functional outcome after central corpectomy for cervical spondylotic myelopathy (CSM) and ossified posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA.: There are limited data on change in T2W ISI morphology after anterior decompressive surgery. It is unclear whether change in T2W ISI carries prognostic significance in patients with CSM/OPLL. METHODS.: We reviewed patients who underwent central corpectomy for CSM/OPLL between 1996 and 2010, and underwent a follow-up magnetic resonance imaging (MRI) at 6 months or later postoperatively. T2W ISI on sagittal images was classified as type 0 no ISI; type 1, predominantly (>50%) faint with an indistinct border; and type 2, predominantly (>50%) intense with a sharp border. The length of T2W ISI and the presence of T1-weighted hypointensity were also recorded on preoperative and follow-up images. Functional outcomes as measured by the Nurick grade were correlated with change in morphology of MR signal changes. RESULTS.: Sixty-four patients (60 males, mean age = 50 ± 1.1 yr) were reviewed. The mean follow-up duration was 29 ± 3.5 months. The majority of patients (71.9%) had no change in the type of ISI at follow-up. The type of ISI improved in 13 patients (20.3%), and worsened in 5 patients (7.8%). The mean length of ISI was 26.2 ± 3.4 mm preoperatively and 13.7 ± 1.8 mm at follow-up in 53 patients (P = 0.002). Change in ISI grade or length was not associated with change in Nurick grade at follow-up (P = 0.74, P = 0.5). CONCLUSION.: The type of T2W ISI does not change, but the length of T2W ISI decreases for the majority of patients undergoing anterior cervical decompression for CSM/OPLL. In our series, change in morphology of T2W ISI did not correlate with functional outcome as measured by Nurick grade.