Complications, readmissions, reoperations and patient-reported outcomes in patients with multiple sclerosis undergoing elective spine surgery - a propensity matched analysis.

BACKGROUND CONTEXT

Multiple sclerosis (MS) is an autoimmune, neurodegenerative disease that can lead to significant functional disability. Improving treatment regimens have extended life expectancy and led to an increase in the number of elective spine surgeries for degenerative conditions in the MS population. Recent literature has reported mixed results regarding the efficacy of elective spine surgery for patients with MS. There is also a paucity of literature comparing postoperative patient reported outcomes (PROs) and reoperation rates between patients with and without MS.

PURPOSE

To determine if patients with MS have worse PROs and higher complication, readmission and reoperation rates after elective spine surgery compared with patients without neurodegenerative conditions when adjusting for baseline covariates through propensity matching.

STUDY DESIGN/SETTING: Retrospective review of prospectively collected data from the Quality Outcomes Database (QOD), a national, longitudinal, multicenter spine outcomes registry.

PATIENT SAMPLE

For the lumbar cohort, 312 patients with MS and 46,738 patients without MS were included. The cervical myelopathy cohort included 91 patients with MS and 6,426 patients without MS. The cervical radiculopathy cohort consisted of 103 patients with MS and 13,751 patients without MS.

OUTCOME MEASURES

1. complication rates, 2) readmission rates, 3) reoperation rates, and 4) PROs at 3- and 12-months including ODI/NDI, NRS back/neck/arm/leg pain, mJOA scores and patient satisfaction ratings.

METHODS

Data from the QOD was queried for patients with surgeries occurring between 04/2013-01/2019. Three surgical groups were included: 1) Elective lumbar surgery, 2) Elective cervical surgery for myelopathy, 3) Elective cervical surgery for radiculopathy. Patients with any neurodegenerative condition other than MS were excluded. Patients without MS were propensity matched against patients with MS in a 5 to 1 ratio without replacement based on ASA grade, arthrodesis, surgical approach, number of operated levels, age, and baseline ODI/NDI, NRS leg/arm pain, NRS back/neck pain, and EQ-5D. Multivariable regressions with cluster-robust standard errors were used to estimate average effect of how the outcome would change if the MS patient didn't have the disease. The mean difference was used for continuous outcomes and the risk difference was used for binary outcomes.

RESULTS

For the lumbar cohort, no differences were found between the 2 groups at 3 or 12 months in any of the outcome measures. For the myelopathy cohort, patients with MS patients had a lower rate of reoperation at 12 months (risk difference=-0.036, p=.007) and worse 3-month mJOA scores (mean difference=-1.044, p=.004) compared with patients without MS. For the radiculopathy cohort, patients with MS had a lower rate of reoperation at 3 months (risk difference=-0.019, p=.018) and 12 months (risk difference=-0.029, p=.007) compared with those without MS.

CONCLUSIONS

Patients with MS had similar PROs compared with patients without MS when adjusting for baseline covariates through propensity matching, except for 3-month mJOA scores in the myelopathy cohort. Reoperation rates were found to be lower in patients with MS undergoing elective cervical surgery for both myelopathy and radiculopathy. These results suggest that when analyzed independently, a diagnosis of MS does not significantly impact complication, readmission and reoperation rates or PROs, and therefore should not represent a major contraindication to elective spine surgery. Surgical decisions in this patient population should be made based on careful consideration of patient factors including other comorbidities as well as baseline patient functional status.