Cementing techniques in hip resurfacing.
The subject of the cementing technique in hip resurfacing has been poorly studied to date. The hip resurfacing prosthesis is unique in the family of cemented prostheses because the cement mantle is blind (hidden underneath the implant) and is radiographically obscured. This presents an immediate challenge to the surgeon at the time of surgery, but also has a longer-term implication in terms of lack of post-operative clinical observation. This should be compared with total hip replacement or total knee replacement where the cement mantle can at least be partially observed both intra- and post-operatively. With this in mind, the objective of this review is, firstly, to understand the cement mantles typically achieved in current clinical practice and, secondly, to identify those factors affecting the cement mantle and to consolidate them into an improved and reproducible cementing technique. The outcome of this work shows that the low-viscosity technique can commonly lead to excessive cement penetration in the proximal femoral head and an incompletely seated component, whereas a more consistent controlled cement mantle can be achieved with a high-viscosity cementing technique. Consequently, it is recommended that a high-viscosity technique should be used to minimize the build-up of excessive cement, to reduce the temperature created by the exothermic polymerization, and to help to ensure correct seating of the prosthesis. A combination of these factors is potentially critical to the clinical success of some articular surface replacement (ASR) procedures. It is important to note that we specifically studied the DePuy ASR system; therefore only the general principles (and not the specifics) of the cementing technique may apply to other resurfacing prostheses, because of differences in internal geometry, clearance, and surgical technique.