RESULTS:: The 6.35 mm rods were used more often for patients who were male, taller, heavier, with larger coronal curves, and more flexible curves. Larger diameter rods were also more likely to be stainless steel, implanted with an increased number of implants per level, and an increased number of pedicle screws used on the concavity of the curve. Univariate analysis of coronal curve showed a significant difference between 5.5 and 6.35 mm rods in correction (67.0% vs. 57.3%) at 2 years. Multivariate analysis revealed that the most significant factors affecting coronal curve correction at 2 years were rod diameter, the patient's preoperative coronal major curve and flexibility, and the implant density. In the sagittal plane, preoperative sagittal curve and rod diameter are the predictors of sagittal correction at 2 years.
CONCLUSIONS:: The study did not support our hypothesis that larger rods would be associated with a greater correction of frontal and sagittal plane in patients with AIS. In addition to rod diameter, implant density and the inherent flexibility and deformity of the patient were found to be influential factors contributing for the correction and maintenance of coronal and sagittal curves in AIS.
PMID: 23863413 [PubMed - as supplied by publisher]
Read more... http://www.ncbi.nlm.nih.gov/pubmed/23863413?dopt=Abstract