RESUMEN
BACKGROUND: According to previous studies, the relationship between lumbar lordosis and thoracic kyphosis or that between pelvic parameters and thoracic kyphosis have been inconsistent. OBJECTIVE: The purpose of this study was to investigate spinal sagittal alignment and its relationship to global and regional lumbar and thoracic angles, pelvic and sway angles, and C7-S1 distance measurements, followed by a detailed subgroup analysis using an inertial measurement unit system. METHODS: A total of 51 asymptomatic volunteers stood in a comfortable posture with inertial measurement units attached to the T1, T7, T12, L3, and S2 vertebrae. T1, T7, T12, L3, and S2 sagittal angles were acquired during standing posture using the Eulerian angle coordinate system. All angles are reported as the mean of three 5-s measurements. Following the measurement of lumbar lordosis angles (T12 relative S2), participants were divided into the flat lumbar and normal lordosis groups. RESULTS: There were different correlation patterns between groups because of spinal sagittal imbalance, which was greater in the flat lumbar group than in the normal lordosis group. In addition, sacral inclination proved the ideal parameter to evaluate reciprocal balance in lumbar lordosis, showing a stronger correlation with lower than with upper lumbar lordosis. T1 was the key element in assessing thoracic kyphosis, which showed a stronger correlation with upper than with lower thoracic kyphosis. CONCLUSION: We suggest that when assessing posture, it is necessary to identify the global and regional angles and it is useful to classify spinal sagittal alignment into subgroups according to lumbar lordosis and evaluate the groups separately.
Asunto(s)
Cifosis , Lordosis , Humanos , Vértebras Lumbares , Sacro , Postura , Vértebras TorácicasRESUMEN
Background: The initial descriptions of successful management of non-fusion surgeries in the management of unstable burst injuries of the thoracic and thoracolumbar spine (TTLS) were published by Osti in 1987 and Sanderson in 1999. These were further supported by prospective studies and meta-analyses establishing comparable results between fusion and non-fusion surgeries. However, there is a paucity of literature regarding the efficacy of non-fusion surgeries in the management of AO type C injuries. Objective, Materials and Methods: The study aims to determine the efficacy of open posterior instrumented stabilization without fusion in AO type C injuries of the TTLS. Patients with AO type C injuries of the TTLS (T4-L2 levels) with normal neurology who underwent open, posterior, long segment instrumented stabilization without fusion between January 2015 and June 2018 were included. The regional kyphotic angle, local kyphotic angle, AP (anterior and posterior wall) ratio, and cumulative loss of disc space angle were assessed on radiographs. Functional outcome was assessed using Oswestry Disability Index (ODI) and the AO Spine patient-reported outcome spine trauma (PROST) instrument. Results and Conclusion: The study included 35 patients with AO type C injury of the TTLS and a normal neurology who underwent open posterior instrumented stabilization and had a mean follow-up of 43.2 months (range 24-60 months). The mean preoperative regional kyphotic angle decreased from 19.8 ± 13.7° to 6.6 ± 11.3° after surgery but showed an increase to 9.21 ± 10.5° at final follow-up (P = 0.003). The cumulative loss of disc space angle was significant at final follow-up (2.4 ± 5° [P = 0.002]). Twenty-eight out of 35 patients had minimal while seven had moderate disability on the ODI score. The AO Spine PROST revealed that patients regained 95.7 ± 4.2% of their pre-injury functional status at final follow-up. Posterior instrumented stabilization without fusion in the management of AO type C injuries of the TTLS gives satisfactory results with acceptable functional and radiological outcomes.