Frailty index as predictors of loss of cervical lordosis following laminoplasty in patients with cervical spondylotic myelopathy

Background: Postlaminoplasty kyphotic deformity (PKD) is a complication affecting roughly 20% of patients undergoing cervical laminoplasty. Identification of preoperative risk factors for PKD could allow surgeons to adapt treatment plans to reduce PKD. Objective: The aim of this study was to investigate the ability of the Charlson Comorbidity Index (CCI), 5-item Modified Frailty Index (5i-mFi), and Administrative Risk Analysis Index (RAI-A) to predict for the development of PKD in patients with cervical spondylotic myelopathy (CSM) undergoing laminoplasty. Materials and Methods: We retrospectively reviewed CSM patients who underwent laminoplasty at an academic tertiary care center between January 1, 2016, and January 30, 2022, and had a complete set of anterolateral cervical X-rays at 1-year follow-up. Angular kyphosis was defined as the loss of cervical lordosis by more than - 10° after surgery when measuring the difference between pre- and post-operative C2-7 Cobb angles. Regression and receiver operating characteristic (ROC) curve analysis were used to assess the ability of the frailty assessments to predict for PKD. Results: Seventy-six CMS patients were eligible, 11.8% of which developed PKD. The cohort consisted of 54 males and 22 females with a mean age of 59.5 years and body mass index of 29.2 kg/m². No CCI, 59-mFi, or RAI-A frailty subgroup was associated with kyphotic development and ROC curve analysis showed that neither CCI (P = 0.81), 5i-mFi (P = 0.59), nor RAI-A (P = 0.63) predicted for PKD. None of these assessments were a superior prognosticator of PKD. Conclusion: CCI, 5i-mFi, and RAI-A frailty assessments were not associated with the development of PKD in CSM patients.