Introduction: Complex spinal osteotomies including 3CO are performed to correct ASD. 3CO procedures are associated with high complication rates, but risk factors and variability among centers for surgical revision have not been reported.
Methods: Multicenter, retrospective review of ASD patients who underwent 3CO (n=335). Incidence and indication for revision surgery (RS) were analyzed. RS indications were classified as “Mechanical” (MR: implant failure, pseudarthrosis, junctional failure, loss/lack of correction) or “Non Mechanical” (NMR: neurologic deficit, infection, wound dehiscence, stenosis).
Results: 3month and 1year RS incidences were 12.3% and 17.6%. Single-level 3CO (n=311) had smaller RS rates than multi-level 3CO (n=24, 15.7% vs. 41.7%, p=0.01). Thoracic (n=63) and lumbar 3CO (n=246) demonstrated similar RS rates (12.7% vs. 16.7%, p=0.112). Rate of RS for single-level lumbar 3CO was 16.7% (MR=11.4%, NMR=5.7%). For all RS, 50% of MR and 78.6% of NMR occurred within 3mo of index surgery. There was variation of RS across sites (range=2.5-32.4%, p=0.004), however low- and high-volume sites had similar RS rates (18.2% vs. 16.2%, p=0.503). Patients with MR were more likely to be under-corrected at 3mo (SVA=7cm vs 3.2cm, p=0.003) and had more caudal 3CO (L4 vs L3, p=0.014). SVA at 3mo and treatment center were the only two parameters predictive of MR and for RS due to pseudarthrosis (p<0.02). Patients with NMR had larger 3CO resections than patients that did not have NMR (34° vs 24.5°, p=0.003).
Conclusions: 3CO procedures for ASD surgery provide deformity correction despite established complication and revision rates. There is great interest in lowering RS rates, particularly in high-risk osteotomy cases, due to their impact on the patient and healthcare system. This study shows that RS is associated with lower level osteotomy and greater SVA. There is significant variability in revision rates across sites which may be a reporting bias, or technique difference.
Patient Care: Improve our understanding of surgical treatment strategies for adults with spinal deformity.
Learning Objectives: By the conclusion of this session, participants should be able to: (1) Appreciate the complication rates associated with use of three-column osteotomies in the surgical treatment of adult spinal deformity; (2) Appreciate the risk factors and variability among centers for surgical revision associated with three-column osteotomies performed for adult spinal deformity correction.