Impact of Connector Placement and Design on Bending Stiffness of Spinal Constructs.
World Neurosurg
; 121: e89-e95, 2019 Jan.
Article
en En
| MEDLINE
| ID: mdl-30217782
ABSTRACT
OBJECTIVE:
To evaluate the stability of multiple rod-connector construct designs using a mechanical 4-point bending testing frame.METHODS:
A mechanical study was used to evaluate the bending stiffness of 3 connectors across 12 different configurations of rod-connector-rod constructs. Stability was evaluated in flexion-extension and lateral bending. Combinations of rods having 1 of 3 diameters (4.0 mm, 5.5 mm, and 6.0 mm) connected by 1 of 3 connector types (parallel open, snap-on, and hinged) were compared. Configurations with single connectors and with double connectors with variable spacing were also compared to simulate revision surgery conditions.RESULTS:
Constructs consisting of 4.0-mm rods connected to 4.0-mm rods were significantly less stiff as the total number of connectors used in a series exceeded 2. When single-connector configurations were compared, parallel open rod connectors demonstrated greater stiffness in flexion-extension than hinged open connectors, whereas hinged open connectors demonstrated greater stiffness in lateral bending. Using double connectors increased stiffness of 4.0- to 4.0-mm rod configurations in flexion-extension and lateral bending, 4.0- to 6.0-mm rod configurations in flexion-extension, and 5.5- to 6.0-mm rod configurations in lateral bending. Spacing the double connectors significantly improved lateral bending stiffness of 4.0- to 4.0-mm and 5.5- to 6.0-mm rod configurations.CONCLUSIONS:
Our data indicate that the design, number, and placement of rod connectors have a significant impact on the bending stiffness of a surgical construct. Such mechanical data may influence construct design in primary and revision surgeries of the cervical spine and cervicothoracic junction.Palabras clave
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Fusión Vertebral
/
Vértebras Cervicales
Tipo de estudio:
Evaluation_studies
Límite:
Humans
Idioma:
En
Revista:
World Neurosurg
Asunto de la revista:
NEUROCIRURGIA
Año:
2019
Tipo del documento:
Article