The Influence of Cervical Spondylolisthesis on Clinical Presentation and Surgical Outcome in Patients With DCM: Analysis of a Multicenter Global Cohort of 458 Patients.

STUDY DESIGN

Ambispective study with propensity matching.

OBJECTIVE

To assess the impact of cervical spondylolisthesis (CS) on clinical presentation and surgical outcome in patients with degenerative cervical myelopathy (DCM).

METHODS

A total of 458 magnetic resonance images (MRIs) from the AOSpine CSM-NA and CSM-I studies were reviewed and CS was identified. Patients with DCM were divided into 2 cohorts, those with CS and those without, and propensity matching was performed. Patient demographics, neurological and functional status at baseline and 2-year follow-up were compared.

RESULTS

Compared with nonspondylolisthesis (n = 404), CS patients (n = 54) were 8.8 years older ( < .0001), presented with worse baseline neurological and functional status (mJOA [modified Japanese Orthopaedic Association Assessment Scale], = .008; Nurick, = .008; SF-36-PCS [Short Form-36 Physical Component Score], = .01), more commonly presented with ligamentum flavum enlargement (81.5% vs 53.5%, < .0001), and were less commonly from Asia ( = .0002). Surgical approach varied between cohorts ( = .0002), with posterior approaches favored in CS (61.1% vs 37.4%). CS patients had more operated levels (4.3 ± 1.4 vs 3.6 ± 1.2, = .0002) and tended to undergo longer operations (196.6 ± 89.2 vs 177.2 ± 75.6 minutes, = .087). Neurological functional recovery was lower with CS (mJOA [1.5 ± 3.6 vs 2.8 ± 2.7, = .003]; Nurick [-0.8 ± 1.4 vs -1.5 ± 1.5, = .002]), and CS was an independent predictor of worse mJOA recovery ratio at 2 years (B = -0.190, < .0001). After propensity matching, improvement of neurological function was still lower in CS patients (mJOA [1.5 ± 3.6 vs 3.2 ± 2.8, < .01]; Nurick [-0.8 ± 1.4 vs -1.4 ± 1.6, = .02]).

CONCLUSIONS

CS patients are older, present with worse neurological/functional impairment, and receive surgery on more levels and more commonly from the posterior. CS may indicate a more advanced state of DCM pathology and is more likely to result in a suboptimal surgical outcome.