Wirbelk�rperersatz in der Wirbels�ulenchirurgie

Abstract

Autografts and allogeneous bone grafts as well as cages are used for the reconstruction of the anterior column after corpectomy. Recently, expandable cages for vertebral body replacement have been developed. Based on our own experience, the purpose of this study was to summarize the available biomechanical and clinical data of expandable corpectomy cages and to compare it with established fixation techniques. If used correctly, expandable cages offer several surgical advantages in comparison to non-expandable cages. However there were no significant differences between the biomechanical properties of expandable and non-expandable cages. Additionally, design variations of expandable corpectomy cages did not show any significant impact on the biomechanical stability. Currently available mid-term clinical and radiological data on the treatment of fractures, metastasis and infection of the cervical, thoracic and lumbar spine demonstrated no significant difference between expandable and non-expandable cages. However, the increased stress-shielding effect of expandable cages compared to non-expandable cages might result in a deterioration of the long-term clinical outcome.

Cage subsidence in anterior spinal reconstruction and its clinical outcomes following anterior and posterior stabilization in thoracolumbar fractures

“…The standard treatment for the incompetent anterior column is corpectomy of the vertebral body via an anterior approach. However, it is important to note that complications such as loss of correction due to tilting or subsidence of cages may occur within the rst year post-surgery and cannot be entirely prevented [9][10][11][12]. Therefore, it is essential to be aware of these potential issues.…”

Implants for Vertebral Body Replacement – Which Systems are Available and Have Become Established

“…Eine Reposition durch Distraktion ist über den Harms-Cage entsprechend nicht möglich. Zudem ist die exakte Rotationseinstellung erforderlich, um Achsabweichungen zu vermeiden [50]. Die Abstützung des Zylinder-Cages kann bei Endplattendefekten oder Osteoporose erschwert sein, da die Abstützung am kortikalen Rahmen bei rundem Implantatdesign meist nicht vollständig möglich ist.…”

“…6). Ein zeitintensives Zuschneiden wie beim nicht expandierbaren Harms-Cage entfällt [50]. Es besteht jedoch das Risiko für Anschlussfrakturen bei erhöhtem Druck auf die benachbarten Endplatten, insbesondere bei niedriger Knochenqualität [58].…”

“…Expandierbare Cages zeigen häufig breitere Möglichkeiten der individuellen Anpassung (Größe, Breite, Endplatten). In biomechanischen Untersuchungen zeigte jedoch das Cage-Design von untersuchten expandierbaren Implantaten keinen Unterschied hinsichtlich der biomechanischen Eigenschaften untereinander und im Vergleich zum nicht expandierbaren Harms-Cage [28,50,80]. Langzeitergebnisse hinsichtlich Fusion und Stabilität von expandierbaren Cages im Vergleich mit nicht expandierbaren Cages sind in der Literatur nicht abschließend geklärt.…”

Secondary Collapse of an Expandable Cage After Vertebral Corpectomy

“…In-situ expandable cages have technical advantages from a surgical standpoint, and some can be completely implanted endoscopically. However, clinical and radiological mid-term results have not shown any significant advantages compared to the implantation of non-expandable vertebral body replacement systems, allogenous or autogenous bone grafts [10]. It is important to understand the specific complications associated with expandable vertebral body replacement systems.…”