Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. May 18, 2019; 10(5): 219-227
Published online May 18, 2019. doi: 10.5312/wjo.v10.i5.219
Precontoured buttress plate vs reconstruction plate for acetabulum posterior wall fractures: A biomechanical study
Güray Altun, Gürsel Saka, Teyfik Demir, Fatma Kübra Erbay Elibol, Mehmet Orçun Polat
Güray Altun, Department of Orthopaedics and Traumatology, University of Health Sciences Umraniye Training and Research Hospital, Ümraniye, Istanbul 34764, Turkey
Gürsel Saka, Department of Orthopaedics and Traumatology, Intercontinental Hisar Hospital, Ümraniye, Istanbul 34768, Turkey
Teyfik Demir, Fatma Kübra Erbay Elibol, Department of Mechanical Engineering, TOBB University of Economics and Technology, Çankaya, Ankara 06560, Turkey
Mehmet Orçun Polat, Department of Industrial Engineering, Kadir Has University, Department of Industrial Engineering, Fatih, Istanbul 34083, Turkey
Author contributions: Altun G and Saka G analyzed the data and prepared the pelvis models prior to laboratory study; Demir T and Elibol FKE performed the biomechanical preparation and tests with the models, as well as the statistical evaluation of the results; Altun G, Polat MO and Saka G wrote the manuscript.
Institutional review board statement: This study was exempt from IRB approval, due to its nature as a biomechanical study.
Institutional animal care and use committee statement: This study was exempt from IACUC approval, due to its nature as a biomechanical study.
Conflict-of-interest statement: The authors declare no conflicts of interest related to this study or its publication.
Data sharing statement: There are no additional data.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Güray Altun, MD, Doctor, Surgeon, Orthopaedic and Traumatology Surgeon, Department of Orthopaedics and Traumatology, University of Health Sciences Umraniye Training and Research Hospital, Adem Yavuz Str., Ümraniye, Istanbul 34764, Turkey. gurayaltun@hotmail.com
Telephone: +90-505-7456667
Received: January 21, 2019
Peer-review started: January 22, 2019
First decision: April 11, 2019
Revised: April 30, 2019
Accepted: May 14, 2019
Article in press: May 14, 2019
Published online: May 18, 2019
Processing time: 117 Days and 10.4 Hours
Abstract
BACKGROUND

The purpose of open reduction and internal fixation of acetabulum posterior wall fractures is to restore anatomical structure and stability of the hip joint, in order to start weight bearing as soon as possible and prevent hip arthrosis; restoration of the anatomy should preserve function of the joint as well. Although “special shaped precontoured plates” have been developed in recent years for surgical treatment of this region, studies comparing the traditional plates with the newly designed precontoured plates are lacking.

AIM

To evaluate the biomechanical properties of precontoured anatomic buttress and conventional curved reconstruction plates (CCRPs) for posterior wall acetabulum fracture treatment.

METHODS

Twelve pelvis models were created for testing plate treatment of fracture in the posterior wall of the acetabulum. These 12 pelvis models were used to create 24 hemipelvis models (experimental) by cutting from the sagittal plane and passing over the center of gravity, after which the posterior wall acetabular fractures (of similar type and size) were created. In these experimental models, the right acetabulum was fixed with a 5-hole CCRP, while the left was fixed with a precontoured anatomic buttress plate (PABP). Samples were placed through the test device and were subjected to static load testing, with a constant testing velocity of 2 mm/min until the load reached 2.3 kN or the acetabular fixation failed. Dynamic tests were also performed with sinusoidal wave load, with a maximal load of 2.3 kN and a load ratio of 0.1.

RESULTS

The average stiffness values were 460.83 ± 95.47 N/mm for the PABP and 291.99 ± 118.58 N/mm for the 5-hole CCRP. The precontoured anatomic acetabulum buttress plates had significantly higher rigidity than the CCRPs (P = 0.022). There was a statistically significant difference between the unloaded and 2.3 kN-loaded values of AL (posterosuperior fracture line vertical to the ground surface) and CL (posteroinferior fracture line vertical to the ground surface) parameters for both the PABPs and the 5-hole CCRPs (P = 0.036 and P = 0.045, respectively). According to the static tests, the amount of total displacement was significantly less in the PABPs than in the CCRPs. Comparative analysis of the displacement in the BL (posterior wall fracture line horizontal to the ground) parameter yielded no statistically significant differences between the PABP and the 5-hole CCRPs (P = 0.261).

CONCLUSION

PABP provides more stable fixation in acetabulum posterior wall fractures than 5-hole CCRP, allowing for proximal or distal fracture line screw application without reshaping.

Keywords: Acetabular fracture; Anatomical plate; Precontoured plate; Posterior wall fracture; Biomechanical study

Core tip: The results of this biomechanical study demonstrated that application of precontoured anatomic acetabular buttress plates in posterior wall fractures of the acetabulum provide more stable fixation than 5-hole conventional curved reconstruction plates. For the precontoured anatomic acetabular buttress plate, its features of anatomic contour, low profile, avoidance of joint penetration by locking screws, and allowance of placement of more screws through both the proximal and distal parts of a fracture pattern as needed represent marked advantages over the traditional plate.