Análisis morfométrico de pedículos torácicos en escoliosis idiopática del adolescente / Morphometric analysis of thoracic pedicles in adolescent idiopathic scoliosis

Existen pocos estudios relacionados con la morfometría del pedículo en la población latinoamericana con escoliosis idiopática del adolescente (EIA). El objetivo del trabajo es destacar las características morfométricas del pedículo en pacientes venezolanos con EIA; por lo que se realizó un estudio prospectivo. Los pacientes fueron sometidos a rastreo tomográfico computarizado (TC). El pedículo de la concavidad es ligeramente de mayor diámetro y con mayor angulación medial que el lado convexo, especialmente en la región apical de la curva escoliótica; la profundidad de inclusión al cuerpo vertebral era menor del lado convexo en comparación con el cóncavo. La anatomía del pedículo en pacientes con escoliosis muestra altas variaciones individuales y un estudio cuidadoso de la TC preoperatoria es esencial para la planificación de instrumentación transpedicular. Tornillos ligeramente más largos pueden ser introducidos en el lado de la concavidad en comparación con el lado convexo(AU)

There are few studies related to pedicle´s morphometry in Latin American population and adolescent idiopathic scoliosis (AIS). Objective was to highlight Venezuelan´s AIS morphometric characteristics in this prospective study. Computer Tomographic (CT) Scan was performed to patients. The pedicle of the concavity has a slightly larger diameter and greater angle than the convexity, particularly in the apical region of the scoliosis curve; vertebral body inclusion depth was lower on the convex side as compared with the concave side. Pedicle´s anatomy in patients with scoliosis shows high individual variations and a careful study of preoperative CT planning is essential for transpedicular instrumentation. Slightly longer screws can be introduced into the side of the concavity compared with the convex side, despite the difference in the depth of inclusion in the vertebral body is not statistically significant in most of the levels(AU)

Pedicular and Extrapedicular Morphometric Analysis in the Korean Population : Computed Tomographic Assessment Relevance to Pedicle and Extrapedicle Screw Fixation in the Thoracic Spine

OBJECTIVE: To evaluate the anatomical parameters that must be considered when performing thoracic transpedicular or extrapedicular screw fixation. METHODS: We selected 958 vertebrae (1,916 pedicles) from 98 patients for analysis. Eight parameters were measured from CT scans : the transverse outer pedicular diameter, transverse inner pedicular diameter, length, angle, chord length of the pedicles and the transverse width, angle, and chord length of the pedicle-rib units. RESULTS: The age of the patients ranged from 21 to 82 years (mean : 48.2 years) and there were 57 men and 41 women. The narrowest transverse outer pedicular diameter was at T5 (4.4 mm). The narrowest pedicle length was at T1 (15.9 mm). For pedicle angle, T1 was 31.6 degrees, which was the most convergent angle, and it showed the tendency of the lower the level, the lesser the convergent angle. The chord length showed a horizontal pattern with similar values at all levels. For the PRU width, T5 showed a similar pattern to the pedicle width at 13.4 mm. For the PRU angle, T1 was the largest angle at 46.2 degrees and the tendency was the lower the level, the narrower the angle. For chord length, T1 was the shortest at 46.9 mm and T8 was the longest at 60.1 mm. CONCLUSION: When transpedicular screw fixations carried out at the mid-thoracic level, special care must be taken because there is a high chance of danger of medial wall violation. In these circumstances, extrapedicular screw fixation may be considered as an alternative treatment.