Vertebral pedicle anatomy in relation to pedicle screw fixation: a cadaver study

Abstract

New techniques to stabilize and correct the thoracic and lumbar spine have been developed in recent years. In view of the wide variety and complexity of fixation devices, the optimum configuration of spinal instrumentation systems needs to be defined. Linear and angular measurements of both vertebral pedicles were made in ten complete thoracic and lumbar cadaveric spines using callipers and a goniometer. The vertical interpedicular distance gradually increased along the spine up to L5. The transverse interpedicular distance was larger at both ends of the spine. Pedicular height gradually increased from T1 to L5, plateauing between T3 and T9, being widest at the thoracolumbar junction. Pedicular width was greatest at the three junctional regions of the spine. The sagittal pedicular angle decreased along the length of the spine to zero at L5. The transverse pedicular angle decreased from T1 to T12 and then increased to L5. Of the pedicular measurements only width limits the diameter of fixation screws. The vertical interpedicular distance determines the distance between the holes of plates, while the length of the transfixator is related to the transverse interpedicular distance. The pedicular angles enable triangulation of screws and determine the stability of the fixation.

Pedicle Morphometry for Thoracic Screw Fixation in Ethnic Koreans : Radiological Assessment Using Computed Tomographic Myelography

“…In this study, similar to other studies, TOPD was shown a decreasing dimension from T1-T4 followed by an increasing dimension from T5-T8 1,9,12,14,15,18) . Fig.…”

“…The risk from the pedicle violation of the screw is higher because the thoracic pedicles are smaller and variable compared with lumbar pedicles. It is hardly surprising that the rate of reported pedicle wall perforation in the thoracic spine ranges from 15.9 to 54.7% 1,8,13,21) . Despite the difficulty in precise instrumentation, there are few reports on analysis of the thoracic pedicle morphometry.…”

Improvement of Fixing Method for the Surgical Assistance Robot and Optimization of Body-Mounted Robotic System

“…α and β axes are coplanar and the intersection of these two axes is a pivot point of needle guide. According to the study of Chaynes [8], the transverse pedicular angle of spinal bone is ≦ 31˚ and the sagittal pedicular angle is ≦ 25˚ to a median position. Therefore, the angle of needle insertion is about 30 degrees [8] to a median position.…”

A Morphometric Study of Dry Human Typical Thoracic Vertebral Body in Telangana Region.

“…In the upper thoracic region, due to the anterior curvature, the main part of the compressive force is transmitted through the anterior column formed vertebral body and intervertebral disc, with resulting increased stress (3) . The compressive force in the lower thoracic region is transmitted through two parallel columns, one anterior and one posterior formed by successive articulations of laminae with each other (4) .In recent years, there have been considerable developments in instrumentation designed to stabilize and correct the thoracic spine (5) . Anterior inter body fusion, in association with a variety of methods to stabilize both the implant and motion segment, has increased in popularity.…”