Development of the Forgotten Spine Surgery Score for Cervical Spine Surgery (FS3-C)

Study Design. Prospective questionnaire development and validation study. Objective. To develop and validate a new “Forgotten Spine Surgery Score for Cervical Spine Surgery” (FS3-C) to assess patient outcomes after CDR beyond the traditional measures: the ability to forget the presence of the implanted disc in daily life. Summary of Background Data. The Forgotten Joint Score (FJS) has demonstrated superior discrimination in high-functioning total joint arthroplasty patients due to low ceiling and floor effects compared to legacy patient-reported outcome measures (PROMs). To date, there is no similar outcome measure to assess “forgottenness” following spine surgery. Such measures may be critical for evaluating subtle differences in high-performance surgeries like cervical disc replacement (CDR). Methods. A 20-item pilot questionnaire was developed based on published patient expectations and expert opinion, utilizing a 5-point Likert scale. This was administered to 41 patients who underwent primary one- or two-level CDR (minimum 3-month follow-up, 2016-2023) for item selection and internal validity assessment. The final 12-item FS3-C was validated in 97 patients and correlated with the neck disability index (NDI) to determine convergent validity. Results. In the pilot cohort (mean age 44.7±7.9 y), four items were excluded due to high missing responses or ceiling effects. In the pilot cohort (mean age 44.7±7.9 y), four items were excluded due to high missing responses or ceiling effects. The remaining 16 items demonstrated high internal consistency (Cronbach’s alpha 0.95-0.96). Pairwise correlation analysis reduced the questionnaire to 12 items. In the validation cohort (mean age 44.3±9.0 y, 56.7±24.2 mo post-surgery), FS3-C demonstrated high internal consistency with minimal ceiling effects. Mean FS3-C and NDI scores were 86.4±18.9 and 9.8±12.6, respectively, with strong correlation (r=-0.606, P <0.001). Conclusion. The FS3-C demonstrates high internal consistency, low ceiling effects, and strong convergent validity with NDI, enabling spine surgeons to evaluate CDR success beyond traditional symptom improvement measures. Level of Evidence. II