Comparative morbidity and outcomes for adult spinal deformity corrections spanning C2-pelvis compared to T4-pelvis: a propensity score-matched analysis.

PURPOSE: Surgical corrections for adult spinal deformity (ASD) often extend from T4-pelvis. Certain patients may require fusion from C2-pelvis. Comparisons are necessary to guide surgical decision-making, particularly for frailer patients with multiple comorbidities. This study analyzed the additional morbidity incurred by proceeding with fusion to the upper cervical spine (i.e., C2) versus to T4.

METHODS

This was a retrospective analysis comparing C2-pelvis versus T4-pelvis fusions for ASD. Patients were propensity-matched in a 1:4 ratio based on age, sex, ASA score, BMI, smoking, diabetes, and use of 3-column osteotomy. Outcomes included postoperative complications, hospital/ICU length-of-stay (LOS), time-to-ambulation, 30- and 90-day readmission rates, reoperations, and overall survival (OS).

RESULTS

80 patients (16 C2-pelvis, 64 T4-pelvis) were analyzed. All patients had ASA scores ≥ 3. C2-pelvis yielded higher complication rates (100% C2-pelvis vs. 68.7% T4-pelvis; p = 0.008) and number of complications per patient (3.2 ± 2.2 C2-pelvis vs. 1.3 ± 1.6 T4-pelvis; p = 0.004). For specific complications, C2-pelvis more often yielded prolonged hypotension requiring vasopressors (p < 0.001), psychiatric complications (p = 0.04), and delirium (p = 0.04). Hospital LOS was similar between cohorts (p = 0.33), but ICU LOS (p = 0.02) and time-to-ambulation (p = 0.046) were longer after C2-pelvis. C2-pelvis had higher readmission rates within 30 (p = 0.001) and 90 (p = 0.001) days. OS was shorter after C2-pelvis (24.4 ± 2.8 months vs. 68.5 ± 4.2 months for T4-pelvis; p < 0.001).

CONCLUSIONS

C2-pelvis fusions for ASD yield significantly higher rates/numbers of complications, longer ICU LOS, longer time-to-ambulation, higher readmission rates, and shorter OS than T4-pelvis fusions, even among patients of similar age and systemic disease/comorbidities. Greater follow-up and numbers of C2-pelvis patients are required for more definitive outcome comparisons.