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Biomechanical study of a novel self-locking plate system for anterior cervical fixation.

Lao L, Li Q, Zhong G, Song C, Li Y, Xu M, Liu Z - J Orthop Surg Res (2014)

Bottom Line: Cervical spine stability increased significantly after internal fixation.Compared to the DePuy plate, the novel anterior cervical self-locking plate system described here has good strength and fastening ability, allowing it to provide sufficient biomechanical stability.Further clinical assessment of this system is needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. zhonggb2014@gmail.com.

ABSTRACT

Background: Anterior cervical plate had developed continuously, and this study aimed to assess the biomechanics of a novel self-locking plate system for anterior cervical fixation designed by ourselves.

Methods: Twelve anterior cervical plates (i.e., six novel plates and six DePuy plates) were subjected to a pull-out test and a fatigue test. In addition, 12 C1-T1 cervical spine specimens underwent anterior cervical corpectomy and C5 fusion using six novel plates and six DePuy plates. Pre- and postoperative range of motion, load-displacement, axial stiffness, torque, and twisting stiffness were compared.

Results: No differences in maximum pull-out force, relative displacement, or energy absorption were observed between the DePuy plates and the novel plates (P >0.05). The novel plate system could bear an average of 5.6 × 105 times of loading, while the DePuy plate could bear 5.4 × 105 times of loading. The fatigue strengths of the new plate system and the DePuy plate were 490.75 and 485.86 MPa, respectively. No differences in fatigue life or strength were observed between the two types of plates. Cervical spine stability increased significantly after internal fixation. No differences in range of motion, load-displacement, axial stiffness, torque, or twisting stiffness were observed between the novel self-locking plate and the DePuy plate (P >0.05).

Conclusions: Compared to the DePuy plate, the novel anterior cervical self-locking plate system described here has good strength and fastening ability, allowing it to provide sufficient biomechanical stability. Further clinical assessment of this system is needed.

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Related in: MedlinePlus

Screw and ring and the lateral view of the self-locking plate system. (A, C) The polyethylene ring that is fitted into the screw hole and the screw. (B, D) A lateral view of the self-locking plate system, which employs a polyethylene ring to lock the screw into the plate.
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Fig1: Screw and ring and the lateral view of the self-locking plate system. (A, C) The polyethylene ring that is fitted into the screw hole and the screw. (B, D) A lateral view of the self-locking plate system, which employs a polyethylene ring to lock the screw into the plate.

Mentions: A national patent certificate (Patent No.: ZL201220153176.7) was obtained for the novel plate system, including the steel and the screw. The plate was made using a titanium alloy. The key design feature is a polyethylene ring built into the plate’s screw hole. The polyethylene ring has a conical angle of 20° and a range of motion of 15°–30° in the screw hole. The end of the screw has an external thread cycle, and the tail top has an inner six-angle groove, which can be matched with a six-angle screwdriver. The plate and screw length can be modified according to the length requirements of different models (Figure 1). This study was approved by the ethics committee of Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine (approval number: RJ20110034). The fresh adult cadaveric cervical spine specimens were obtained anonymously, and all of them were donated to Anatomy Laboratory, Shanghai Jiao Tong University School of Medicine. So, our ethics committee waived the need for consent from the donor for use of this sample in research.Figure 1


Biomechanical study of a novel self-locking plate system for anterior cervical fixation.

Lao L, Li Q, Zhong G, Song C, Li Y, Xu M, Liu Z - J Orthop Surg Res (2014)

Screw and ring and the lateral view of the self-locking plate system. (A, C) The polyethylene ring that is fitted into the screw hole and the screw. (B, D) A lateral view of the self-locking plate system, which employs a polyethylene ring to lock the screw into the plate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4247882&req=5

Fig1: Screw and ring and the lateral view of the self-locking plate system. (A, C) The polyethylene ring that is fitted into the screw hole and the screw. (B, D) A lateral view of the self-locking plate system, which employs a polyethylene ring to lock the screw into the plate.
Mentions: A national patent certificate (Patent No.: ZL201220153176.7) was obtained for the novel plate system, including the steel and the screw. The plate was made using a titanium alloy. The key design feature is a polyethylene ring built into the plate’s screw hole. The polyethylene ring has a conical angle of 20° and a range of motion of 15°–30° in the screw hole. The end of the screw has an external thread cycle, and the tail top has an inner six-angle groove, which can be matched with a six-angle screwdriver. The plate and screw length can be modified according to the length requirements of different models (Figure 1). This study was approved by the ethics committee of Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine (approval number: RJ20110034). The fresh adult cadaveric cervical spine specimens were obtained anonymously, and all of them were donated to Anatomy Laboratory, Shanghai Jiao Tong University School of Medicine. So, our ethics committee waived the need for consent from the donor for use of this sample in research.Figure 1

Bottom Line: Cervical spine stability increased significantly after internal fixation.Compared to the DePuy plate, the novel anterior cervical self-locking plate system described here has good strength and fastening ability, allowing it to provide sufficient biomechanical stability.Further clinical assessment of this system is needed.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. zhonggb2014@gmail.com.

ABSTRACT

Background: Anterior cervical plate had developed continuously, and this study aimed to assess the biomechanics of a novel self-locking plate system for anterior cervical fixation designed by ourselves.

Methods: Twelve anterior cervical plates (i.e., six novel plates and six DePuy plates) were subjected to a pull-out test and a fatigue test. In addition, 12 C1-T1 cervical spine specimens underwent anterior cervical corpectomy and C5 fusion using six novel plates and six DePuy plates. Pre- and postoperative range of motion, load-displacement, axial stiffness, torque, and twisting stiffness were compared.

Results: No differences in maximum pull-out force, relative displacement, or energy absorption were observed between the DePuy plates and the novel plates (P >0.05). The novel plate system could bear an average of 5.6 × 105 times of loading, while the DePuy plate could bear 5.4 × 105 times of loading. The fatigue strengths of the new plate system and the DePuy plate were 490.75 and 485.86 MPa, respectively. No differences in fatigue life or strength were observed between the two types of plates. Cervical spine stability increased significantly after internal fixation. No differences in range of motion, load-displacement, axial stiffness, torque, or twisting stiffness were observed between the novel self-locking plate and the DePuy plate (P >0.05).

Conclusions: Compared to the DePuy plate, the novel anterior cervical self-locking plate system described here has good strength and fastening ability, allowing it to provide sufficient biomechanical stability. Further clinical assessment of this system is needed.

Show MeSH
Related in: MedlinePlus