Recovery of Physical Function Based on Body Mass Index Following Anterior Cervical Discectomy and Fusion
Elliot D K Cha1, Conor P Lynch1, James M Parrish1
1Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL, USA.
Background:
Body mass index (BMI) serves as a risk factor for complications and poorer outcomes following anterior cervical discectomy and fusion (ACDF). This study investigates the association between BMI and Patient Reported Outcomes Measurement Information System physical function (PROMIS-PF) following ACDF.
Methods:
A prospectively maintained surgical registry was retrospectively reviewed for cervical spine surgeries between 2015 and 2019. Included patients underwent elective primary, single, or multilevel ACDF and were excluded for missing preoperative PROMIS-PF. Patients were stratified into 4 groups based on BMI score. Associations of demographic and perioperative characteristics with BMI groups were analyzed using either χ2 test or t test. PROMIS-PF was evaluated preoperatively and 6 weeks, 12 weeks, 6 months, 1 year, and 2 years postoperatively using linear regression. Delta improvement in PROMIS-PF was evaluated at all time points.
Results:
The 128 study cohort had 74 patients the nonobese, 27 in the Obese I, 19 in the Obese II, and 8 in the Obese III groups. The mean age was 50.0 years and 57.0% were male. Gender, diabetic status, and Charlson Comorbidity Index (CCI) significantly differed by BMI groups but did not differ by perioperative characteristics. Preoperative PROMIS-PF did not significantly differ by group. Obese II and III groups had decreased PROMIS-PF compared to Obese I and nonobese groups at 1 year and 2 years. BMI groups had significantly different delta improvement at the 12 weeks (4.1 vs 10.1 vs 1.8 vs 4.3; P = 0.044) and 2 years (9.9 vs 7.1 vs 2.3 vs 3.0; P = 0.048).
Conclusion:
Among the assessed BMI subgroups, all experienced similar physical function scores during the preoperative and short-term time points. Patients with higher BMI demonstrated diminished physical function at long-term time points. While this study focused on evaluating obesity, longitudinal tracking of high-risk patients during the postoperative period remains important for optimal rehabilitation.
Level Of Evidence:
4.
Clinical Relevance:
High BMI may predispose patients to lengthier recovery of physical function following ACDF.
