Description
The basic design of the twinSys stem system is based on the straight-stem prosthesis concept by Prof. Maurice E. Müller. The twinSys system has been distributed since 2003 with the aim of enabling surgeons to perform cemented and uncemented implan-tation with a single instrumentation.
The uncemented twinSys stem is a straight monoblock prosthesis available in XS, Standard, Lateral and Long versions. It has a triply conical stem geometry and a pronounced proximal rib structure to counteract forces acting axially on the stem. The stem design strives to achieve primary pressfit anchoring in the proximal cancellous bone. Data from a study conducted specifically to this end show that the twinSys stem design reduces the risk of postoperative subsidence and provides secondary stability.
The selected cross-sectional geometry increases the stability of the implant against rotational forces acting on it. 1 In order to counteract premature distal stem locking and reduce the risk of femoral pain, the stem is provided with a tapered distal prosthesis tip.
Using the plasma spray process, a hydroxyapatite coating is applied to the corundum-blasted surface in order to support osseointegration of the implant into the bone. 2
Benefit
- Same instrumentation for implantation of the cemented and uncemented stems
- Triply conical design to convert shear forces into compressive forces and achieve good primary stability 1
- Proximal rib structure with the aim of reducing postoperative subsidence 1
- Support of osseointegration by the hydroxyapatite coating 2
- 7 A* ODEP Rating 3
1 Clauss, M., et al., Prospective five-year subsidence analysis of a cementless fully hydroxyapatite-coated femoral hip arthroplasty component. Hip Int, 2014. 24(1): p. 91-7.
2 Wintermantel E. and Ha S.W. Medizintechnik, Life Science Engineering. Book, 2009. 5. Auflage.
3 Latest ODEP ratings can be found at www.odep.org.uk.