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Revision of cemented fixation and cement-bone interface strength
A Rosenstein1, W MacDonald, A Iliadis
1Nuffield Orthopaedic Centre, Headington, Oxford.
Summary
Revision surgery for cemented joint arthroplasties can weaken bone-cement interfaces. Fresh cement adhering to existing surfaces may offer better fixation than removing all traces of poly(methyl methacrylate) bone cement.
Area of Science:
- Orthopedic surgery
- Biomaterials science
- Biomechanical engineering
Background:
- Poly(methyl methacrylate) (PMMA) bone cement is widely used in joint arthroplasty.
- Assessing the mechanical integrity of the bone-cement interface is crucial for long-term implant success.
- Revision surgeries often involve managing existing cement-bone fixation.
Purpose of the Study:
- To quantify the interfacial shear strength between PMMA bone cement and cancellous bone.
- To compare the strength of primary cement fixation with fixation after revision procedures.
- To evaluate fixation when fresh cement interfaces with existing cement mantles.
Main Methods:
- Human proximal femur cancellous bone samples were used.
- Push-out tests were conducted to measure interfacial shear strength.
- Three interface conditions were tested: fresh cement-bone, fresh cement-existing cement, and fresh cement-revised bone.
Main Results:
- Failure consistently occurred at the bone-cement interface.
- Revised bone interfaces demonstrated a 30% reduction in shear strength compared to primary interfaces (P < 0.02).
- Fresh cement adhering to existing cement surfaces was also evaluated.
Conclusions:
- Revision of cemented arthroplasties may compromise bone-cement fixation strength.
- Aggressive removal of all PMMA cement during revision may not be optimal.
- Consideration of adhering fresh cement to prepared existing cement surfaces could be beneficial in certain revision scenarios.