2022 Volume 13 Issue 7 Pages 958-964
Purpose: We investigated the factors associated with cage subsidence (CS) in segments treated with anterior column realignment (ACR) in patients who underwent minimally invasive spinal fusion using ACR, extreme lateral interbody fusion (XLIF), and percutaneous pedicle screw (PPS) placement for management of adult spinal deformity (ASD).
Methods: The study included 42 patients with ASD, who underwent surgical correction using ACR, XLIF, and PPS between 2018 and 2020 and were followed up for >12 months. Patients were categorised into the cage subsidence group (Group CS, 13 patients) and the non-cage subsidence group (Group NCS, 29 patients). We recorded the surgical level, range of fusion, segmental lordosis (SL), anterior disc height (ADH), posterior disc height, cage lordotic angle, anterior and posterior cage heights, cage position, and spinopelvic parameters.
Results: The mean age was higher and posterior cage height was significantly lower in Group CS. A significantly larger number of patients used 30° cages and had an anterior cage position. Postoperative pelvic incidence-lumbar lordosis was higher and SL and ADH were lower in Group CS. Logistic regression analysis using CS as the dependent variable showed that use of the 30° cage was a risk factor for CS.
Conclusions: We investigated factors associated with CS in segments treated with ACR and also the optimal cage position in patients who underwent surgical correction using ACR, XLIF, and PPS. We observed that placement of a 20° lordotic cage at the centre of the vertebral body may prevent CS and achieve good lordosis.
