Saint-Lambert, Canada
Saint-Lambert, Canada

Time filter

Source Type

Driscoll M.,Spinologics Inc. | Mac-Thiong J.-M.,Spinologics Inc. | Labelle H.,Spinologics Inc. | Slivka M.,DePuy | And 2 more authors.
Spine Deformity | Year: 2013

Study Design: Biomechanical finite element models simulated deformity correction using pedicle screw instrumentation and measured forces at the screw-vertebra interface. Objectives: Compare 2 different screw designs with respect to reaction forces at screw-vertebra interfaces during scoliosis correction maneuvers. Summary of Background Data: Pedicle screw developments strive to enhance surgical techniques and improve patient safety. It is believed that a screw with increased lateral angulation and reduction tabs enables a more gradual correction, more effectively distributes corrective forces over multiple levels, and reduces forces at screw-vertebra interfaces compared with standard polyaxial screws. Methods: We selected 3 scoliotic patients and reconstructed their preoperative spinal profiles as finite element models using radiographic clinical measures. The osteoligamentous models were programmed and validated with mechanical properties from published literature. We used postoperative radiographs to determine instrumented levels and calibrate disc properties to corroborate simulated results with clinical data. We alternatively examined favored angle (FA) screws and polyaxial (PA) screws using correction steps characteristic to their design. We also explored sensitivity of screw forces consequent to misalignment with adjacent screws. Results: Simulated postoperative spinal profiles on average adhered to clinical measures within 5°. We observed no significant differences in simulated corrective profiles between screw types (5° or less). Compared with PA screws, FA screws reduced peak pullout and lateral forces by 27% and 35%, respectively, and correspondingly reduced mean pullout and lateral forces by 48% and 40%, respectively. Changes in peak and average pullout forces resulting from screw misalignment were 56% and 82% less, respectively, with FA screws. Conclusions: This analysis demonstrated reduced screw-vertebra peak and mean forces when using a pedicle screw with a favored angle bias and reduction tabs to correct scoliosis. Compared with PA screws, FA screws provide similar correction, decrease forces applied at the screw-vertebra interface, and are more forgiving if misaligned. © 2013 Scoliosis Research Society.

Driscoll M.,Spinologics Inc. | Mac-Thiong J.-M.,Spinologics Inc. | Labelle H.,Spinologics Inc. | Parent S.,Spinologics Inc.
BioMed Research International | Year: 2013

A large spectrum of medical devices exists; it aims to correct deformities associated with spinal disorders. The development of a detailed volumetric finite element model of the osteoligamentous spine would serve as a valuable tool to assess, compare, and optimize spinal devices. Thus the purpose of the study was to develop and initiate validation of a detailed osteoligamentous finite element model of the spine with simulated correction from spinal instrumentation. A finite element of the spine from T1 to L5 was developed using properties and geometry from the published literature and patient data. Spinal instrumentation, consisting of segmental translation of a scoliotic spine, was emulated. Postoperative patient and relevant published data of intervertebral disc stress, screw/vertebra pullout forces, and spinal profiles was used to evaluate the models validity. Intervertebral disc and vertebral reaction stresses respected published in vivo, ex vivo, and in silico values. Screw/vertebra reaction forces agreed with accepted pullout threshold values. Cobb angle measurements of spinal deformity following simulated surgical instrumentation corroborated with patient data. This computational biomechanical analysis validated a detailed volumetric spine model. Future studies seek to exploit the model to explore the performance of corrective spinal devices. © 2013 Mark Driscoll et al.

Spinologics Inc. | Date: 2013-03-15

An apparatus enabling inclination measurements or irregular surfaces comprising a retaining end adapted to temporarily hold a device equipped with an inclinometer and a supporting end, fixed to the retaining end, conformed to abut an irregular surface whereby the apparatus enables the device equipped with an inclinometer to measure inclination of an irregular surface.

Loading Spinologics Inc. collaborators
Loading Spinologics Inc. collaborators