Incorporation of Frailty Based Realignment Target Goals for Cervical Deformity Surgery in Adults Can Mitigate Mechanical Complications and Improve Perioperative Course

Introduction: Given the high prevalence of frailty in adults undergoing cervical deformity surgery, along with frailty drastically influencing recovery patterns, adjusting realignment goals can be of value. Assessing patient specific goals accounting for frailty, can lead to greater rates of optimal outcomes in ACD.

Methods: Operative adult cervical deformity(ACD) patients with 2-year data were included. Cervical deformity defined as: patients that met radiographic evidence of cervical deformity, defined previously as meeting at least one of the following radiographic parameters: C2-C7 lordosis <-15°, TS-CL >35°, segmental cervical kyphosis >15° across any 3 vertebrae between C2-T1, C2-C7 SVA >4cm, McGregor’s slope >20°, or CBVA > 25°, measured with preoperative radiographs were included.
Patients were stratified based on mFI into not frail (NF), frail (F), and severely frail (SF). Good outcomes (GO) was defined as meeting all of the following parameters at 1Y and 2Y: 1) no DJF or mechanical failure, 2) met Virk et al. good clinical outcome, NRS-Neck ≤5 or improvement ≥2 points from BL], 3) improved in ≥1 Ames modifier, and 4) no worsening in Ames modifier. Those that did not meet GO were PO. ANCOVA used to control for baseline deformity, levels corrected, and age to assess radiographic alignment on earliest postoperative imaging. Logistic regression analysis followed by conditional inference tree (CIT) run forest analysis generated categorical thresholds. Multivariate analysis controlling for age, baseline deformity, and history of revision.

Results: 343 ACD patients were included (Age 59.6±12.4yrs, 46% females, BMI 28.6 ± 7.1kg/m2). Baseline HRQL’s were NDI 53±19, ODI 48.5±17.5, mJOA 13.2 ± 2.6, Swal 89 ± 22, EQ-5D 0.54 ± 0.21. Baseline frailty categories: 21% Not Frail, 67% Frail, and 12% severely frail. Baseline deformity: TS-CL 36.1°±18.9°, cSVA 4.5±2.4cm, C2-C7 -3.9°±22.2°, C2-T3 -15.5°±21.5°, C2S 35.8°±19.9°, MGS 2.3°±13.0°, with greater deformity present as frailty increased. BL mJOA was worse in SF and in PO cohort (both p< 0.001). Overall by 2Y, 18.9% developed DJK, 7.9% DJF, 6.3% mechanical failure, 11% neurological complications, and 16.5% underwent reoperation, with 43.3% meeting GO. 52% of NF met GO, 42% of F, and 33% of SF. Analysis adjusted for baseline deformity depicted GO had increased correction relative to GO in NF and F, however for SF decreased correction in TS-CL (-6° vs -17°, p=0.047), C2S (-9° vs -19°, p=0.108), and MGS (-12° vs -13.5°, p=0.2).
When assessing the cohort as a whole, improvement in Ames modifiers had correlation with development of DJK, DJF, good outcomes, but not reoperation. GO rates decreased as frailty increased. Cohort with good outcomes had mean baseline TSCL of 40.7 degrees ± 19.2 with correction by 16.1 ± 18.4 degrees. Frail cohort with good outcomes had mean baseline TSCL of 39.6 degrees ± 17.4 with correction by 7.2 ± 18.6 degrees.

Conclusion: Consideration of chronological age, in addition to physiological age, may be beneficial in management of operative goals to maximize clinical outcomes while minimizing junctional failure. This combination enables the spine surgeon to fortify a surgical plan for even the most challenging patients undergoing adult cervical deformity corrective surgery.