In Brief Study Design. Method validation and in vivo motion segment study. Objective. To determine in healthy subjects in vivo intervertebral segmental kinematics and coupled motion behavior in all 3 planes simultaneously for 3 segments and to evaluate whether these results differ from those in the normal population according to the literature. Summary of Background Data. Few studies have provided a direct invasive approach to investigate segmental kinematics in vivo. Dynamic recordings of 3-dimensional segmental motion patterns of adjacent segments have rarely been reported. To date, no studies have examined the 3-dimensional segmental movements of the thoracolumbar junction in vivo in detail. Methods. K-wires were inserted into the Th11, Th12, L1, and L2 spinous processes of 21 healthy subjects. Ultrasound markers and sensors were attached to the k-wires. Real-time motion data were recorded during standardized ranging exercises. Errors caused by the k-wires, and the static and dynamic accuracy of the system, were considered. Results. Large intersubject variation was found in all of the exercises. The average ranges of motion from Th11 to L2 were 18.7° for flexion-extension, 13.5° for one-sided lateral bending, and 1.8° for one-sided axial rotation. Coupled-motion patterns among the subjects showed a coupled flexion in active lateral bending and a coupled extension in active rotation, but the results were inconsistent for active extension and flexion. Conclusion. This method offered accurate multisegmental dynamic-recording facilities. The dynamic exercises showed high reproducibility. The ranges of motion for extension/flexion and lateral bending differed from those reported in previous studies. The coupling patterns were only partly consistent because of large interindividual variation. The measurement error was comparable with that of other invasive methods. The aim of the current study was to determine in healthy subjects in vivo segmental kinematics and coupled motion behavior in all 3 planes simultaneously for 3 segments and to evaluate whether these results differ from those in the normal population according to the literature.
Intraoperative ultrasound of the spine has been used in neurosurgery (tumours) and traumatology (reposition of fractured vertebral bodies fragments).To describe initial experiences with this method and to document the opportunities and problems.24 nucleotomies were documented and evaluated. Sonography was performed using a 7.5 MHz sector probe and a typical surgical approach.In 21 of 24 cases, imaging of intraspinal structures was possible. The complete extraction of the herniated disk could be documented. In 3 cases the examination failed because the probe was too large to be pushed down between the spinous processes and the wound retractor to the operative site.Intraoperative sonography can be used easily as a routine method for exploration of the spinal canal. Technical innovations in the probes would make the method even more feasible.
Die dorsale operative Stabilisierung von Wirbelfrakturen, vor allem des thoracolumbalen Überganges, mit einem Fixateur interne ist ein etabliertes Verfahren der Traumatologie. Das Ziel ist hier neben der Aufrichtung der Kyphose und der Wiederherstellung der Wirbelkörperhöhe die Dekompression des Myelons durch die Reposition von Knochenfragmenten, die von der frakturierten Wirbelkörperhinterkante in den Spinalkanal hineinragen. In vielen Fällen gelingt die indirekte Reposition der Hinterkante alleine durch Kyphosekorrektur und Distraktion. In anderen Fällen muß der Wirbelkanal durch Laminektomie freigelegt und die Hinterkante direkt reponiert werden. Die Möglichkeiten, den Erfolg des Repositionsmanövers vor der Laminektomie mittels Tasthaken oder Röntgenbildwandler intraoperativ zu überprüfen, sind unsicher. Die intraoperative Myelographie ist aufwendig und von beschränkter Aussagekraft, da das Kontrastmittel an den dislocierten Knochenfragmenten vorbeifließen und unauffällige Befunde vortäuschen kann. Hier bietet sich die intraoperative Sonographie mit einem speziellen kleinen Schallkopf an, wobei allerdings der von Knochen umgebene Wirbelkanal der Ultraschalluntersuchung schwer zugänglich ist. Die Laminektomie zur Schallapplikation trägt zur weiteren DeStabilisierung der verletzten Wirbelsäule bei.
