69. Coronal correction using the kickstand rod technique: a pilot adult scoliosis study and analysis of early outcomes and complications

Abstract

BACKGROUND CONTEXT A major goal of adult spinal deformity (ASD) surgery is more harmonious spinal alignment. Sagittal alignment has been emphasized since it was demonstrated to have the greatest impact on postoperative pain and functional outcomes. However, growing evidence suggests the impact of coronal alignment has likely been underestimated. Kickstand rods are a new technique recently utilized for achieving coronal balance. The kickstand spans from the thoracolumbar junction to a 3rd iliac screw. Using the iliac wing as a base, kickstand distraction produces powerful coronal realignment forces. Limited literature exists for this novel technique, and its associated outcomes and complications after ASD surgery are unknown. PURPOSE The objective of this pilot study was to investigate early outcomes and complications after coronal correction with kickstand rods. STUDY DESIGN/SETTING Retrospective review of single-center database. PATIENT SAMPLE Consecutive ASD patients. OUTCOME MEASURES Radiographic alignment correction using standing long-cassette films (both coronal and sagittal spinopelvic measurements), back and leg pain assessed with numerical rating scale (NRS) scores (0-no pain; 10-unbearable pain), and associated complications. METHODS All ASD patients who had deformity correction using kickstand rods. Demographic, surgical, coronal- and sagittal-plane radiographic measurements, and back and leg pain NRS scores were analyzed. A kickstand rod correction classification was devised to illustrate our technique: Subtype (1a) Curve Pattern: C7PL towards major concavity and fractional convexity; Kickstand Distraction: corrects major curve onlySubtype (1b) Curve Pattern: C7PL towards major concavity with neutral/concave fractional curve; Kickstand Distraction: corrects major curve +/- simultaneous fractional correction; Subtype (2) Curve Pattern: C7PL towards major convexity; Kickstand Distraction: corrects fractional curve +/- simultaneous major correction; Subtype (3) Curve Pattern: global coronal balance with scoliosis; Kickstand distraction corrects major curve, but typically after fractional correction “shifts” the spine. RESULTS The cohort comprised 19 patients (mean age: 67±7 yrs; 79% women; 63% prior lumbar fusion) with mean follow-up 21 weeks (range: 2-72 weeks). All patients had posterior-only approach surgery with tri-iliac fixation (3rd iliac screw for the kickstand) for mean fusion length 12 levels. Kickstand correction was subtype 1a, 1b, 2, and 3 in 4 (21%), 6 (32%), 7 (37%), and 2 (9%) patients, respectively. 3-column osteotomy and lumbar TLIF were performed in 5 (26%) and 15 (79%) patients, respectively. Alignment was significantly improved (coronal balance: 8 to 1cm [p CONCLUSIONS Kickstand rod distraction can achieve significant coronal correction in ASD. Kickstand subtype 1a+b was most commonly utilized (since coronal curves with C7PL shifted to the major curve concavity are most common). Back and leg pain were significantly improved, and complications rates were reasonable. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.