Risk factors for distal junctional failure following three-column osteotomy for cervical deformity correction.

Objective: The purpose of this study was to determine risk factors for distal junctional failure (DJF) following three-column osteotomy (3CO) for the correction of cervical deformity.

Methods: A retrospective review was performed of patients who underwent a cervical or upper thoracic 3CO for cervical deformity correction by the senior author from 2008 to 2023. The main outcome of interest was DJF, defined as revision surgery with extension of the distal end of the fusion construct. Patients were excluded if the lowest instrumented vertebra (LIV) was the sacrum/pelvis, and if patients had prior autofusion throughout the distal part of the spine to the sacrum (e.g., ankylosing spondylitis). The minimum follow-up duration was 1 year.

Results: One hundred fourteen patients were identified who underwent a cervical or upper thoracic 3CO for cervical deformity correction, 41 of whom met inclusion criteria for this study. The median patient age was 66 years, median BMI was 27, and 61% were male. Ten patients (24%) experienced DJF, requiring reoperation and distal extension of the construct to the pelvis in 9 cases and to L1 in 1 case. On univariable analysis, patients who experienced DJF compared with those who did not were more likely to be female (80% vs 35%, p = 0.007), had lower LIV Hounsfield units (HUs; 127 vs 167, p = 0.041), were less likely to have an LIV in a small autofused segment (10% vs 45%, p = 0.02), had an LIV that was closer to the first lordotic level (one level above vs three, p = 0.043), and had a longer length of fusion (17 vs 13 levels, p = 0.033). A stepwise multivariable regression model showed that having an LIV closer to the first lordotic vertebra was the only statistically significant predictor of DJF (OR 0.49, p = 0.013) and low LIV HUs did not reach statistical significance (OR 0.97, p = 0.09).

Conclusions: Patients with cervical deformity undergoing a 3CO are at higher risk for DJF with constructs terminating near the first lordotic vertebra. While LIV selection is complex and patient specific, choosing an LIV at least two levels above the first lordotic vertebra may help prevent DJF.