Kickstand rods and correction of coronal malalignment in patients with adult spinal deformity.

ABSTRACT

PURPOSE: Coronal malalignment (CM) is a challenging spinal deformity to treat. The kickstand rod (KR) technique is powerful for correcting truncal shift. This study tested the hypothesis that the KR technique provides superior coronal alignment correction in adult deformity compared with traditional rod techniques. METHODS: A retrospective evaluation of a prospectively collected multicenter database was performed. A 21 matched cohort of non-KR accessory rod and KR patients was planned based on preoperative coronal balance distance (CBD) and a vector of global shift. Patients were subgrouped according to CM classification with a 30-mm CBD threshold defining CM, and comparisons of surgical and clinical outcomes among groups was performed. RESULTS: Twenty-one patients with preoperative CM treated with a KR were matched to 36 controls. KR-treated patients had improved CBD compared with controls (18 vs. 35 mm, P < 0.01). The postoperative CBD did not result in clinical differences between groups in patient-reported outcomes (P ≥ 0.09). Eight (38%) of 21 KR patients and 12 (33%) of 36 control patients with preoperative CM had persistent postoperative CM (P = 0.72). CM class did not significantly affect the likelihood of treatment failure (postoperative CBD > 30 mm) in the KR cohort (P = 0.70), the control cohort (P = 0.35), or the overall population (P = 0.31). CONCLUSIONS: Application of the KR technique to coronal spinal deformity in adults allows for successful treatment of CM. Compared to traditional rod techniques, the use of KRs did not improve clinical outcome measures 1 year after spinal deformity surgery but was associated with better postoperative coronal alignment.