Clinical Outcomes of Decompressive Spine Surgery for Painless Cervical Myelopathy: Analysis of the Michigan Spine Surgery Improvement Collaborative Registry.

Abstract

Background and objectives: Although axial neck pain and radicular arm pain are often associated with cervical spondylotic myelopathy (CSM), some patients present or are discovered to have CSM without pain. Little is known regarding the surgical outcomes in these patients. Our objective is to describe the outcomes of decompressive spine surgery in a cohort of patients treated for painless CSM.

Methods: This is a retrospective study of data from the Michigan Spine Surgery Improvement Collaborative registry. A total of 407 patients undergoing spine surgery for painless CSM between March 2014 and May 2022 were analyzed. Patient-reported outcomes (PROs), including minimal clinically important difference (MCID) in Modified Japanese Orthopedic Association, EuroQol-5 Dimension (EQ-5D), and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) scores, were assessed at baseline, and at 90 days, 1 year, and 2 years postoperatively. All analyses were conducted with a P-value of < .05 being considered significant.

Results: After surgery, the number of patients experiencing a clinically significant improvement in PROs was greatest at 1 year (49% PROMIS PF MCID, 36% Modified Japanese Orthopedic Association MCID, 42% EQ-5D MCID). When stratifying by preoperative CSM severity, patients with severe myelopathy were significantly more likely to have a poorer discharge disposition and readmission at 90 days compared with mild myelopathy patients. PROs also significantly varied by CSM severity, including patient satisfaction at 2 years (95% mild vs 80% moderate vs 74% severe, P < .05), PROMIS PF MCID at 90 days (26% mild vs 53% moderate vs 45% severe, P = .02), and mean EQ-5D at 90 days (0.84 mild vs 0.80 moderate vs 0.69 severe, P < .01), 1 year (0.85 mild vs 0.79 moderate vs 0.82 severe, P < .01), and 2 years (0.85 mild vs 0.75 moderate vs 0.76 severe, P < .01).

Conclusion: After surgery, a clinically significant improvement was seen in a modest number of patients. In addition to halting the progression of myelopathy, surgery may enhance functional status and quality of life in some with painless CSM.