Originally created in the mid 70’s by Professor Gilles BOUSQUET in St Etienne (France), the dual articulation acetabular socket rationale has kept improving since then, and offers nowadays a comprehensive solution to intra-prosthetic dislocation.
Indicated for primary arthritis patients above 70 years old, for femoral neck fractures whenever the patient is valid and active, for any patient presenting an important hip joint laxity, for patients with irrational behaviour, and for most hip revision cases, the dual mobility concept combines a high level of protection against dislocation and a controled and well documented polyethylene wear rate.
The CAPITOL T cup keeps the “Tripod” fixation imagined from the origins of his experience by Professor Bousquet. The clinical publications showing the largest follow-ups deal only with the “tripod” cup.
Its principle of fixation is based on the theory of the ” 3 feet stool “: the principle is a spontaneous stability whatever the ground.
2 pegs of fixation are set to the cup by conical fixation, and are directed in the branches of the ischion and the pubis. The third point of fixation is a screw oriented 15 – 20 ° above the horizontal in the roof of the acetabulum.
This principle proved an excellent long-term stability in spite of the original coating which did not allow any bony fixation to the cup.
CAPITOL T renews this original concept by adding a dual coating of porous titanium and hydroxyapatite.
Thanks to the acquired experience with the tripod cups, as well as to the scientific and technical advances regarding osteoconductive coatings, dual mobility cups evolved towards a simple press-fit fixation.
The primary stability is insured by a peripheral oversizing and by the “scratch effect” of the surface roughness due to the porous titanium.
Furthermore, the couple forces generated in the “small” joint and inferred by the articular movements, faint in in the “large” joint, so protecting the osseous fixation from sheer stresses.
The impaction of the cup in the acetabulum is done in a simple one-step procedure. Suitable with mini-approaches, the impaction of the CAPITOL I cup does not require any additional step or preparation.
The articular surface between the cup and the liner is fully smooth and the liner is completely supported. The wear particles cannot migrate into the acetabulum, and the friction is optimized. The polyethylene liners are made of PEXEL.