Initial stability of fully and partially cemented femoral stems
L Claes1, S Fiedler, M Ohnmacht
1Institut für Unfallchirurgische Forschung und Biomechanik, Universität Ulm, Helmholtzstrasse 14, 89081, Ulm, Germany. lutz.claes@medizin.uni-elm.de
Clinical Biomechanics (Bristol, Avon)
|October 26, 2000
Summary
The new partially cemented femoral stem (Option 3000) demonstrated comparable initial stability to the fully cemented Weber prosthesis. This finding supports the clinical use of the novel implant design for hip replacements.
Area of Science:
- Orthopaedic biomechanics
- Biomaterials science
Background:
- Novel prosthesis design aims for proximal load transfer via partial cement fixation.
- A slim distal stem design is incorporated.
- Initial stability must be comparable to fully cemented stems before clinical trials.
Purpose of the Study:
- To evaluate the initial stability of a new partially cemented femoral stem.
- To compare its stability against a conventional fully cemented stem.
Main Methods:
- In vitro study using six paired cadaveric femora.
- Cyclic loading up to 1600 N to simulate hip joint forces.
- Measurement of interface motion between implant and bone at six locations for both stem types.
Main Results:
- Both stems exhibited interface motions below 43 micrometers, considered uncritical.
- The Option 3000 stem showed significantly less proximal motion compared to the Weber prosthesis.
- Slightly greater distal motion was observed for the Option 3000 stem.
Conclusions:
- The partially cemented Option 3000 stem achieves initial stability comparable to the fully cemented Weber prosthesis.
- High initial stability supports the clinical application of the Option 3000 stem.
- Preliminary clinical results from over 100 implantations are positive.
