Trajectory of Improvement in Myelopathic Symptoms From 3 to 12 Months Following Surgery for Degenerative Cervical Myelopathy

Neurosurgery 86:763–768, 2020

Degenerative cervical myelopathy (DCM) is a progressive disease resulting fromcervical cord compression. The modified JapaneseOrthopaedic Association (mJOA) is commonly used to grade myelopathic symptoms, but its persistent postoperative improvement has not been previously explored.

OBJECTIVE: To utilize the Quality Outcomes Database (QOD) to evaluate the trajectory of outcomes in those operatively treated for DCM.

METHODS: This study is a retrospective analysis of prospectively collected data. The QOD was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9-13), or severe (<9) categories for their baseline severity of myelopathic symptoms (mJOA scores). A parsimonious multivariable logistic regression model was fitted with 2 points improvement on mJOA from 3- to 12-mo follow-up as the outcome of interest.

RESULTS: A total of 2156 patients who underwent elective surgery for DCM and had complete 3- and 12-mo follow-up were included in our analysis. Patients improved significantly from baseline to 3-mo on their mJOA scores, regardless of their baseline mJOA severity. After adjusting for the relevant preoperative characteristics, the baseline mJOA categories had significant impact on outcome of whether a patient keeps improving in mJOA score from 3 to 12 mo postsurgery. Patient with severe mJOA score at baseline had a higher likelihood of improvement in theirmyelopathic symptoms, compared to patients with mild mJOA score in.

CONCLUSION: Most patients achieve improvement on a shorter follow-up; however, patients with severe symptoms keep on improving until after a longer follow-up. Preoperative identification of such patients helps the clinician settling realistic expectations for each follow-up timepoint.