Neurological Survivorship Following Surgery For Degenerative Cervical Myelopathy And Outcomes Following Reoperation

Abstract

<div><p><br></p><p>NEUROLOGICAL SURVIVORSHIP FOLLOWING SURGERY FOR DEGENERATIVE CERVICAL MYELOPATHY AND OUTCOMES FOLLOWING REOPERATION</p><p><u>Graham Ka Hon Shea</u>¹*, Changmeng Zhang1, Andy Yee1, Paul Koljonen¹</p><p>1 <em>Orthopaedics and TraumatologY, The University of Hong Kong, Hong Kong</em>​​​​​​​<br></p><p>Introduction</p><p>Long-term data on postoperative neurological survivorship for patients with degenerative cervical myelopathy (DCM) undergoing decompressive surgery are limited. The purposes of this study were to assess neurological survivorship after primary decompressive surgery for DCM and to identify predictors for postoperative deterioration and outcomes of reoperation.</p><p>Methods</p><p>A longitudinal clinical data set containing surgical details, medical comorbidities, and radiographic features was assembled for 195 patients who underwent a surgical procedure for DCM between 1999 and 2020, with a mean period of observation of 75.9 months. Kaplan-Meier curves were plotted, and a log-rank test was performed for the univariate analysis of factors related to neurological failure. Lasso regression facilitated the variable selection in the Cox proportional hazards model for multivariate analysis. Patients requiring reoperation were matched for age, mJOA, and surgical approach to patients receiving primary decompression to analyze for non-inferiority in reaching a minimum clinically important difference</p><p>(MCID) in mJOA of 2.5.</p><p><br></p><p>Results</p><p>The overall neurological survivorship was 89.3% at 5 years and 77.3% at 10 years. Cox multivariate analysis following lasso regression identified elevated hazard ratios {HRs) for suture laminoplasty {HR, 4.76; p < 0.001), renal failure (HR, 4.43; p</p><p>= 0.013), T2 hyperintensity (HR, 3.34; p = 0.05), and ossification of the posterior longitudinal ligament (OPLL) (HR, 2.32; p = 0.032). Subgroup analysis among subjects with OPLL demonstrated that the neurological failure rate was significantly higher in the absence of fusion (77.8% compared with 26.3%; p =</p></div><p><br></p><p>0.019). An increase in mJOA score of 2.7±2.0 following reoperation was similar to that achieved after the primary operation (2.2±2.1, P=0.616). A recovery ratio of 38.1%±25.4% upon revision compared favorably to that following the primary operation (35.0%±37.4%, P=0.867).</p><p><br></p><p>Conclusions</p><p>Overall, patients who underwent a surgical procedure for DCM exhibited an extended period with neurological improvement. Patients were able to make up for lost neurological gains following reoperation. Our findings on predictors for early deterioration facilitate case selection, prognostication, and counseling as the volume of primary cervical spine surgeries and reoperations increases globally.</p>