Schmitz, Paul and Gueorguiev, Boyko and Zderic, Ivan and Pfeifer, Christian and Nerlich, Michael and Grechenig, Stephan (2017) Primary stability in total hip replacement: A biomechanical investigation. MEDICINE, 96 (42): e8278. ISSN 0025-7974, 1536-5964
Full text not available from this repository. (Request a copy)Abstract
Background:In total hip replacement (THR), it is essential to achieve a primary stability to guarantee good long-term results. A novel locking screw hip (LSH)-stem, anchored to the medial cortex of the proximal femur by 5 monocortical locking screws, was developed to overcome the shortcomings of uncemented press-fit and cemented straight stems while simultaneously achieving primary stability. The aim of this study was to investigate the biomechanical competence of the LSH-stem in comparison to an uncemented press-fit stem.Methods:Six pairs of embalmed human cadaveric femora from donors aged 68 to 84 years were assigned to 2 study groups (n=6) with equal number of right and left bones. The specimens in each group and pair were implanted with either an uncemented press-fit stem or an LSH-stem and tested biomechanically under progressively increasing cyclic axial loading until catastrophic failure. Axial construct stiffness, failure load, and cycles to failure were detected and statistically evaluated at a level of significance P=.05.Results:Although the axial stiffness was comparable for both prosthesis types, the uncemented press-fit stem showed a significant lower stability in terms of failure load and cycles to failure in comparison to the LSH-stem, P=.04.Conclusion:Converting our results to percentage of bodyweight (BW) in an assumed adult patient of 80kg shows that the LSH-stem achieves a primary stability allowing to carry average loads of up to 507% BW, whereas the uncemented press-fit stem carried average loads of up to 404% BW. We conclude that both stems achieve a primary stability strong enough to carry hip joint loads experienced in the immediate rehabilitation period after THR.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | FEMORAL STEMS; FOLLOW-UP; BONE; ARTHROPLASTY; PRESERVATION; IMPLANTS; LOCKING; SCREWS; locking screw hip stem; primary stability; screw fixation; total hip replacement |
| Subjects: | 600 Technology > 610 Medical sciences Medicine |
| Divisions: | Medicine > Lehrstuhl für Unfallchirurgie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 Dec 2018 13:19 |
| Last Modified: | 01 Mar 2019 08:11 |
| URI: | https://pred.uni-regensburg.de/id/eprint/2056 |
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