53 - Frailty Index's Association with the Development of Kyphotic Deformity Following Cervical Laminoplasty

Introduction: While cervical laminoplasty is a useful surgery for the management of cervical degenerative disease, the post-operative development of kyphosis is a significant complication that effects approximately 10–15% of patients. The identification of pre-operative risk factors for developing post-laminoplasty kyphotic deformity would allow surgeons to best adapt their treatment plans to avoid this complication. Frailty scores are becoming increasing utilized across surgical disciplines to predict postoperative complications and inform surgical decision making. In this study, we investigated the ability of various frailty assessments to predict for the development of post-laminoplasty kyphotic deformity in patients with cervical spondylotic myelopathy.

Aims/

Objectives: To investigate the use of the Charlson Comorbidity Index (CCI), 5-item Modified Frailty Index (5i-mFi), and Administrative Risk Analysis Index (RAI-A) in predicting the development of post-laminoplasty kyphotic deformity.

Methods: We retrospectively reviewed cervical spondylotic myelopathy patients who underwent laminoplasty at Barnes Jewish Hospital between January 1, 2018 and January 30, 2022. A binary logistic regression was used to assess the ability of CCI, 5i-mFI, and RAI-A frailty assessments to predict for the development of kyphosis, with angular kyphosis defined as a loss of cervical lordosis less than −10° after surgery when measuring the difference between the pre-operative and post-operative C2-7 cobb angle.


Results:
A total of 59 patients with cervical spondylotic myelopathy underwent laminoplasty, 8 of which developed postoperative kyphotic deformity. The kyphotic patient cohort consisted of 2 females and 6 males with a mean age of 62.63 years (48-84) and BMI of 29.56 kg/m2 (26.13-34.72). They had an average CCI of 2.88 (1-7), 5i-mFi of 1.38 (0-2), and RAI-A of 10.00 (0-20). The non-kyphotic patient cohort consisted of 18 females and 32 females with a mean age of 61.48 years (31-89) and BMI of 28.97 kg/m2 (19.70-43.26). They had an average CCI of 3.2 (0-9), 5i-mFi of 1.14 (0-4), and RAI-A of 11.04 (2-40). The binary logistic regression model was able to correctly classify 86.2% of postoperative kyphosis cases and explained only a small proportion of variance in the development of kyphosis (Snell R2 = 0.019, Nagelkerke’s R2 = 0.034). The model indicated that neither CCI (p=0.59), 5i-mFi (p=0.35), nor RAI-A (p=0.87) were significantly associated with the development of post-laminoplasty kyphotic deformity.

Conclusion:
While they may be utilized successfully for the prediction of postoperative complications across various other surgical cases, CCI, 5i-mFi, and RAI-A frailty assessments are not associated with the development of kyphotic deformity in cervical spondylotic myelopathy patients who undergo laminoplasty. Further research is necessary to identify risk factors associated with the development of kyphosis and examine how these measures can be best incorporated into preoperative surgical decision making.