Prediction of 2-year clinical outcome trajectories in patients undergoing anterior cervical discectomy and fusion for spondylotic radiculopathy
Authors: Hébert Jeffrey J. , Adams Tyler , Cunningham Erin , El-Mughayyar Dana , Manson Neil , Abraham Edward , Wedderkopp Niels , Bigney Erin , Richardson Eden , Vandewint Amanda , Small Chris , Kolyvas George , Roux Andre le , Robichaud Aaron , Weber Michael H. , Fisher Charles , Dea Nicolas , Plessis Stephan du , Charest-Morin Raphaele , Christie Sean D. , Bailey Christopher S. , Rampersaud Y. Raja , Johnson Michael G. , Paquet Jerome , Nataraj Andrew , LaRue Bernard , Hall Hamilton , Attabib Najmedden 
Published: September 2022

OBJECTIVE
Anterior cervical discectomy and fusion (ACDF) is often described as the gold standard surgical technique for cervical spondylotic radiculopathy. Although outcomes are considered favorable, there is little prognostic evidence to guide patient selection for ACDF. This study aimed to 1) describe the 24-month postoperative trajectories of arm pain, neck pain, and pain-related disability; and 2) identify perioperative prognostic factors that predict trajectories representing poor clinical outcomes.

METHODS
In this retrospective cohort study, patients with cervical spondylotic radiculopathy who underwent ACDF at 1 of 12 orthopedic or neurological surgery centers were recruited. Potential outcome predictors included demographic, health, clinical, and surgery-related prognostic factors. Surgical outcomes were classified by trajectories of arm pain intensity, neck pain intensity (numeric pain rating scales), and pain-related disability (Neck Disability Index) from before surgery to 24 months postsurgery. Trajectories of postoperative pain and disability were estimated with latent class growth analysis, and prognostic factors associated with poor outcome trajectory were identified with robust Poisson models.

RESULTS
The authors included data from 352 patients (mean age 50.9 [SD 9.5] years; 43.8% female). The models estimated that 15.5%–23.5% of patients followed a trajectory consistent with a poor clinical outcome. Lower physical and mental health–related quality of life, moderate to severe risk of depression, and longer surgical wait time and procedure time predicted poor postoperative trajectories for all outcomes. Receiving compensation and smoking additionally predicted a poor neck pain outcome. Regular exercise, physiotherapy, and spinal injections before surgery were associated with a lower risk of poor disability outcome. Patients who used daily opioids, those with worse general health, or those who reported predominant neck pain or a history of depression were at greater risk of poor disability outcome.

CONCLUSIONS
Patients who undergo ACDF for cervical spondylotic radiculopathy experience heterogeneous postoperative trajectories of pain and disability, with 15.5%–23.5% of patients experiencing poor outcomes. Demographic, health, clinical, and surgery-related prognostic factors can predict ACDF outcomes. This information may further assist surgeons with patient selection and with setting realistic expectations. Future studies are needed to replicate and validate these findings prior to confident clinical implementation.