Melvin C. Makhni, Ying Zhang, Paul J. Park, Meghan Cerpa, Ming Yang, Martin H. Pham, J. Alex Sielatycki, Eduardo C. Beauchamp and Lawrence G. Lenke
The objective of this study was to describe and evaluate a new surgical procedure for the correction of coronal imbalance (CI) in adult spinal deformity patients, called the “kickstand rod” technique.
The authors analyzed the records of 24 consecutive patients with pediatric and adult spinal deformity and CI treated between July 2015 and October 2017 with a long-segment fusion and a kickstand rod. For the kickstand rod technique, an iliac screw was placed on the ipsilateral side of the trunk shift and connected proximally through a side-by-side domino link to the thoracolumbar junction; this rod was distracted to promote coronal plane balancing. Distraction occurred with the rod on the contralateral side locked in order to preserve sagittal correction. Radiographic and clinical analyses were conducted to evaluate the outcomes and possible complications of the kickstand rod technique.
The mean age of the patients was 55 years (range 14–73 years). Eighteen of the 24 patients were female. CI preoperatively was a mean of 63 mm, and the mean measurement at the final follow-up (mean duration 1.4 years) was 47 mm. There were no neurological, vascular, or implant-related complications in any of the patients. One patient developed wound dehiscence that was successfully treated without implant removal, and one developed proximal junctional kyphosis requiring extension of the construct proximally. One patient also returned to the operating room for excision of a spinous process. There were no complaints about screw prominence, kickstand construct failure, or significant worsening of CI after surgery.
The kickstand rod technique is safe and effective for the correction of CI in spinal deformity patients. This technique was found to provide marked coronal correction and additional strength to the overall construct without significant adverse consequences.
Griffin R. Baum, Alex S. Ha, Meghan Cerpa, Scott L. Zuckerman, James D. Lin, Richard P. Menger, Joseph A. Osorio, Simon Morr, Eric Leung, Ronald A. Lehman Jr., Zeeshan Sardar and Lawrence G. Lenke
The goal of this study was to validate the Global Alignment and Proportion (GAP) score in a cohort of patients undergoing adult spinal deformity (ASD) surgery. The GAP score is a novel measure that uses sagittal parameters relative to each patient’s lumbosacral anatomy to predict mechanical complications after ASD surgery. External validation is required.
Adult ASD patients undergoing > 4 levels of posterior fusion with a minimum 2-year follow-up were included. Six-week postoperative standing radiographs were used to calculate the GAP score, classified into a spinopelvic state as proportioned (P), moderately disproportioned (MD), or severely disproportioned (SD). A chi-square analysis, receiver operating characteristic curve, and Cochran-Armitage analysis were performed to assess the relationship between the GAP score and mechanical complications.
Sixty-seven patients with a mean age of 52.5 years (range 18–75 years) and a mean follow-up of 2.04 years were included. Patients with < 2 years of follow-up were included only if they had an early mechanical complication. Twenty of 67 patients (29.8%) had a mechanical complication. The spinopelvic state breakdown was as follows: P group, 21/67 (31.3%); MD group, 23/67 (34.3%); and SD group, 23/67 (34.3%). Mechanical complication rates were not significantly different among all groups: P group, 19.0%; MD group, 30.3%; and SD group, 39.1% (χ2 = 1.70, p = 0.19). The rates of mechanical complications between the MD and SD groups (30.4% and 39.1%) were less than those observed in the original GAP study (MD group 36.4%–57.1% and SD group 72.7%–100%). Within the P group, the rates in this study were higher than in the original study (19.0% vs 4.0%, respectively).
The authors found no statistically significant difference in the rate of mechanical complications between the P, MD, and SD groups. The current validation study revealed poor generalizability toward the authors’ patient population.