Skip to main content
main-content

01.12.2015 | Research article | Ausgabe 1/2015 Open Access

BMC Musculoskeletal Disorders 1/2015

Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses

Zeitschrift:
BMC Musculoskeletal Disorders > Ausgabe 1/2015
Autoren:
Chu-An Luo, Su-Yang Hwa, Shang-Chih Lin, Chun-Ming Chen, Ching-Shiow Tseng
Wichtige Hinweise

Competing interests

The authors declare that they have no competing interests.

Author’s contributions

CAL, SYH, and SCL conceived of the study, participated in the design of the study and performed the data analyses. CAL and SCL formulated the model and drafted the manuscript with the help of CMC and CST. All authors carried out the experiments, read, and approved the final manuscript.

Abstract

Background

High tibial osteotomy (HTO) with a medially opening wedge has been used to treat osteoarthritic knees. However, the osteotomized tibia becomes a highly unstable structure and necessitates the use of plate and screws to stabilize the medial opening and enhance bone healing. A T-shaped plate (e.g. TomoFix) with locking screws has been extensively used as a stabilizer of the HTO wedge. From the biomechanical viewpoint, however, the different plate sites and support bases of the HTO plate should affect the load-transferring path and wedge-stabilizing ability of the HTO construct. This study uses biomechanical tests and finite-element analyses to evaluate the placement- and base-induced effects of the HTO plates on construct performance.

Methods

Test-grade synthetic tibiae are chosen as the standard specimens of the static tests. A medial wedge is created for each specimen and stabilized by three plate variations: hybrid use of T- and I-shaped plates (TIP), anteriorly placed TomoFix (APT), and medially placed TomoFix (MPT). There are five tests for each variation. The failure loads of the three constructs are measured and used as the load references of the fatigue finite-element analysis. The residual life after two hundred thousand cycles is predicted for all variations.

Results

The testing results show no occurrence of implant back-out and breakage under all variations. However, the wedge fracture consistently occurs at the opening tip for the APT and MPT and the medially resected plateau for the TIP, respectively. The testing results reveal that both failure load and wedge stiffness of the TIP are the highest, followed by the MPT, while those of the APT are the least (P < 0.05). The fatigue analyses predict comparable values of residual life for the TIP and MPT and the highest value of damage accumulation for the APT. Both experimental and numerical tests show the biomechanical disadvantage of the APT than their counterparts. However, the TIP construct without locking screws shows the highest stress at the plate-screw interfaces.

Conclusions

This study demonstrates the significant effect of placement site and support base on the construct behaviors. The TIP provides a wider base for supporting the HTO wedge even without the use of locking screws, thus significantly enhancing construct stiffness and suppressing wedge fracture. Compared to the APT, the MPT shows performance more comparable to that of the TIP. If a single plate and a smaller incision are considered, the MPT is recommended as the better alternative for stabilizing the medial HTO wedge.
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2015

BMC Musculoskeletal Disorders 1/2015 Zur Ausgabe

Neu im Fachgebiet Orthopädie und Unfallchirurgie

21.11.2019 | ACR 2019 | Kongressbericht | Onlineartikel

Anifrolumab bei SLE nun doch mit signifikanten Ergebnissen

21.11.2019 | ACR 2019 | Kongressbericht | Onlineartikel

Handarthrose: Tops und Flops vom ACR-Kongress

21.11.2019 | ACR 2019 | Kongressbericht | Onlineartikel

JAK - selektive Inhibitoren bei RA mit Vorteilen?

21.11.2019 | ACR 2019 | Kongressbericht | Onlineartikel

Erste Daten zur Differentialtherapie der PsA

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update Orthopädie und Unfallchirurgie und bleiben Sie gut informiert – ganz bequem per eMail.

Bildnachweise