Three-dimensional translations following posterior three-column spinal osteotomies for the correction of severe and stiff kyphoscoliosis

Publication date: Available online 7 June 2017
Source:The Spine Journal
Author(s): Xueshi Li, Zifang Huang, Yaolong Deng, Hengwei Fan, Wenyuan Sui, Chongwen Wang, Junlin Yang
Background ContextPosterior three-column spinal osteotomies were shown to be effective to treat severe and stiff kyphoscoliosis. Translations at the site of osteotomy after deformity correction were commonly seen intraoperatively, which might cause potential neurologic deficits. However, this phenomenon was not thoroughly discussed in the current literature.PurposeThis study was to evaluate the three-dimensional translations at the three-column osteotomy site and their effects on neurologic outcome in the surgical correction of severe and stiff kyphoscoliosis.Study Design/SettingRetrospective Study.Patient SampleSixty-nine patients treated by posterior three-column spinal osteotomy for severe kyphoscoliosis of idiopathic, congenital, neuromuscular, neurofibromatosis and tuberculosis origin were included.Outcome MeasuresGeneral, coronal and sagittal translations were graded three-dimensionally according to the theory of Meyerding.MethodsThe charts of 69 clinical patients with severe and stiff kyphoscoliosis treated by posterior three-column osteotomy from Jan 2013 to Jun 2015 were reviewed. There were 35 male patients with an average age of 21.5 years and 34 female patients with an average age of 22.5 years. The etiologies of these spinal deformities were idiopathic, congenital, neuromuscular, neurofibromatosis and tuberculosis. According to our classification system of spinal cord neurologic function, there were 41 type A, 13 type B and 15 type C cases. The 3D spine models were reconstructed from thin-sliced CT scan and the three-dimensional translations at the three-column osteotomy site were graded and analyzed.ResultsThe incidence of general translation (GT), frontal translation (FT) and sagittal translation (ST) was 62.3%, 52.2% and 26.1%. The incidence of evoked potential (EP) change in cases with GT/FT being or more than grade II (GT, 42.9%; FT, 50.0%) was significantly higher than that with GT/FT being less than grade II (GT, 16.7%; FT, 18.2%). Whereas the incidence of EP change in cases with ST being or more than grade I (33.3%) was significantly higher than that with ST being less than grade I (9.8%). No linear correlations were found between spine shortening distance, deformity correction rate and the degree of translation.ConclusionsThe three-dimensional translations are common in posterior three-column spinal osteotomies regardless of anterior strut graft placement. The increase of translation will increase neurologic risks with general or frontal translation less than grade II and sagittal translation less than grade I being relatively safe.



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