At the beginning of 2000, Professor Pierre-François Leyvraz, Department Head at the main Orthopaedic Hospital serving French-speaking Switzerland (Hôpital Orthopédique de la Suisse Romande) and Vincent Leclercq, a graduate engineer of the Federal Polytechnic School of Lausanne (EPFL), conducted an in-depth study, both theoretical and clinical, on total knee prostheses currently available on the market.
On the basis of the work undertaken over 15 years at the EPFL, the study led them to develop a new prosthesis with an improved articular design, which makes it possible to reduce the wear of the polyethylene, increase the stability of the implants and increase the amplitude of articular flexion.
A group of European surgeons has also contributed to the development of an optimal operative technique
F.I.R.S.T Prosthesis design
Semi-constrained, ultra-congruent, posterio-stabilised prosthesis with a rotating platform.
The femoral and tibial components are available in both a non cemented version (coated with porous titanium and hydroxyapatite) and a cemented version (the bone apposition surfaces of the femoral and tibial components are sand blasted and polished with micro grinding balls).
The system includes various extension stems/ keels for the tibia (see range of prostheses)
Increased stability F.I.R.S.T implant.
From the standard F.I.R.S.T prosthesis, a more constrained version of the prosthesis – the F.I.R.S.T Evolution – has been developed.
This prosthesis is indicated in those cases in which ligamentary balancing cannot be reproduced during the primary procedure.
The F.I.R.S.T Evolution implant is also suitable for revision of total knee prostheses with a deficient capsulo-ligamentary balance (see range of prostheses).
‘KneePLAN’ pre- operative planning of ‘Personalised’ Total Knee Replacement
KneePLAN is a pre- operative planning software based on careful scrutiny of DICOM images aquired during a ‘Symbios specific protocol’ CT scan. All parameters for optimal positioning of the F.I.R.S.T prosthesis (implant) are identified in HipPlan. Personalised and individualised pre- operative planning allows for the design and manufacture of ‘personalised’ cutting blocks to assist the interoperative placement of the implant. The operating surgeon uses this personalised instrumentation to help achieve optimal stability and positioning, correct alignment and ligament balancing.
KneePlan is a validated planning software based upon over 20 years of 3D planning expertise, using:
- Proprietary computer software
- In- house programming
- Rapid materials addtive (3D printing) manufacturing technology
Advantages for the patient
The F.I.R.S.T knee prosthesis it is capable of recovering an optimal functionality of a healthy knee. The comparative clinical studies in progress show significant differences in terms of gait analysis.
The innovative design of the F.I.R.S.T prosthesis pre-disposes to:
- Immediate articular stability
- Optimised soft tissue balance
- Excellent post-operative functional outcomes
- Implant longevity thanks to optimal positioning of the ultra congruent articular surfaces minimising the risks of wear