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An in-vitro biomechanical study of different fixation techniques for the extended trochanteric osteotomy in revision THA.

Zhu Z, Ding H, Shao H, Zhou Y, Wang G - J Orthop Surg Res (2013)

Bottom Line: Ten cadaveric femurs were chosen in this study.The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively.The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Tsinghua University, Beijing, China.

ABSTRACT

Background: The wire fixation and the cable grip fixation have been developed for the extended trochanteric osteotomy (ETO) in the revision of total hip arthroplasty (THA). Many studies reported the postoperative performance of the patients, but with little quantitative biomechanical comparison of the two fixation systems.

Methods: An in-vitro testing approach was designed to record the loosening between the femoral bed and the greater trochanter after fixations. Ten cadaveric femurs were chosen in this study. Each femur underwent the THA, revision by ETO and fixations. The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively. The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system.

Results: In the vertical tension tests, the overall translation of the greater trochanter was observed 0.4 mm in the cable fixations and 7.0 mm in the wire fixations. In the lateral tension tests, the overall motion of the greater trochanter was 2.0 mm and 1.2° in the cable fixations, while it was 6.2 mm and 5.3° in the wire fixations. The result was significantly different between the two fixation systems.

Conclusions: The stability of the proximal femur after ETO using different fixations in the revision THA was investigated. The cable grip fixation was significantly more stable than the wire fixation.

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The result of the five fixations in the lateral tension test.
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Figure 6: The result of the five fixations in the lateral tension test.

Mentions: The result from the lateral tension test was shown in Figure 6. All of the translations and rotations increased monotonously during testing. The statistical analysis of all fixations under the load of 500 N was given in Figure 6. It was 8.9 ± 7.6 mm in translation and 7.0 ± 5.5 degree in rotation in the test of F1, and 3.5 ± 2.5 mm and 3.6 ± 3.2 degree in the test of F2, with no significant difference between them. Under the tension of 500 N, the translation was 1.8 ± 1.6 mm, 1.9 ± 1.5 mm, and 2.3 ± 1.4 mm for the F3, F4 and F5, respectively. The rotation was 0.9 ± 0.5 degree, 1.0 ± 0.7 degree, and 1.6 ± 1.0 degree for the F3, F4 and F5, respectively. No significant difference was found among them. When the wire fixations (F1) was compared with the cable grip fixations (F3, F4 and F5), a significant difference was found (P≦0.015) in both translation and rotation. There was significant difference in rotation when the test of F2 was compared to the short claw plate fixations (F3, F4).


An in-vitro biomechanical study of different fixation techniques for the extended trochanteric osteotomy in revision THA.

Zhu Z, Ding H, Shao H, Zhou Y, Wang G - J Orthop Surg Res (2013)

The result of the five fixations in the lateral tension test.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643827&req=5

Figure 6: The result of the five fixations in the lateral tension test.
Mentions: The result from the lateral tension test was shown in Figure 6. All of the translations and rotations increased monotonously during testing. The statistical analysis of all fixations under the load of 500 N was given in Figure 6. It was 8.9 ± 7.6 mm in translation and 7.0 ± 5.5 degree in rotation in the test of F1, and 3.5 ± 2.5 mm and 3.6 ± 3.2 degree in the test of F2, with no significant difference between them. Under the tension of 500 N, the translation was 1.8 ± 1.6 mm, 1.9 ± 1.5 mm, and 2.3 ± 1.4 mm for the F3, F4 and F5, respectively. The rotation was 0.9 ± 0.5 degree, 1.0 ± 0.7 degree, and 1.6 ± 1.0 degree for the F3, F4 and F5, respectively. No significant difference was found among them. When the wire fixations (F1) was compared with the cable grip fixations (F3, F4 and F5), a significant difference was found (P≦0.015) in both translation and rotation. There was significant difference in rotation when the test of F2 was compared to the short claw plate fixations (F3, F4).

Bottom Line: Ten cadaveric femurs were chosen in this study.The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively.The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Tsinghua University, Beijing, China.

ABSTRACT

Background: The wire fixation and the cable grip fixation have been developed for the extended trochanteric osteotomy (ETO) in the revision of total hip arthroplasty (THA). Many studies reported the postoperative performance of the patients, but with little quantitative biomechanical comparison of the two fixation systems.

Methods: An in-vitro testing approach was designed to record the loosening between the femoral bed and the greater trochanter after fixations. Ten cadaveric femurs were chosen in this study. Each femur underwent the THA, revision by ETO and fixations. The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively. The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system.

Results: In the vertical tension tests, the overall translation of the greater trochanter was observed 0.4 mm in the cable fixations and 7.0 mm in the wire fixations. In the lateral tension tests, the overall motion of the greater trochanter was 2.0 mm and 1.2° in the cable fixations, while it was 6.2 mm and 5.3° in the wire fixations. The result was significantly different between the two fixation systems.

Conclusions: The stability of the proximal femur after ETO using different fixations in the revision THA was investigated. The cable grip fixation was significantly more stable than the wire fixation.

Show MeSH
Related in: MedlinePlus