6.1. Lexicon of the own expressions
Anchoring Zone
Principal area of an implant, providing fixing in the bone. Calculated with my Original and Specific Processes, the Anchoring Zone respects the Principles of Geometrical Anchoring.
Antetorsion
Expression which indicates the angle between the axis of the femoral or prosthetic collar and the frontal plane, projected down on a horizontal plane. Expression intended to avoid the frequent confusion with the acetabular anteversion as defined by the orientation that evokes a hollow object. This expression is well suited for modular prostheses to express the rotation of the proximal part of a vertical axis.
Arc of Calcar
The Arc of Calcar is a transition curve , mathematically defined, which connects in a progressive way the zone of anchoring and the collar of a stem. It is only one of the elements of the Calcar Polynomial Deckner. Previously, only of the arcs of circle were used. I modelled the Arc of Calcar of the Alloclassic stem by a Hyperbole, in the SL-Plus stem an Exponential auto-adjusted by iterations and dichotomy, in the Modular stem plane Missile Shootings, and in AnaNova stems three-dimensional Missile Shootings.
Ascending Nesting
Geometrical property of two implants of consecutive size or more, which present facing the bone in their zone of ââfixation, a part of sufficient axial length, anchoring portions in all respects identical, so that the Geometric Anchoring takes place for each of the two sizes, in the same bone bed, but at different levels, without new preparation of the bone.
Bicon
I called âBiconâ the Titanium cup comprising a main area in truncated cone to 15°, and a secondary cone of approximately 50°. The principal cone, pressed against the bone at the end of the screwing, functions like a Conical Junction. The frontal secondary cone, whose angular aspect is opposed to the swing, brings the cup closer to the spherical general form, avoids the perforation of the bottom of the acetabulum and saves the bone during milling.
Calcar Polynomial
Expression deposited under the name of âCalcar Polynom Decknerâ, designating a heavy complete mathematical formulation of all the points of the medial contour of a femoral stem. It is not a classical Polynomial. The exponents are Reals. It comprises several exponential functions, and is controlled to an about sixty parameters.
Coordinate Base
In the system Implant Descriptor, a giant Spreadsheet stores simultaneously coordinates X Y Z of all the points of all the 16 sizes. All the 160000 points are numbered, identified, reusable by all the programs of the system and are consultable on screen during development.
Curved Space in Logarithmic Spiral
It is a method of three-dimensional description of a prosthetic stem whose curvilinear axis is in the shape of a logarithmic spiral curve. It is the only means of carrying out a junction of a conical type for a curved implant. Details in Patent 9.8.5.
Distal Ogive
Curved area at the tip of the stem intended to avoid any risk of false route during insertion. It is an exponential function, last term of the Polynomial of Calcar.
Distal Ski
Characteristic shape of the lateral tip side of my cemented stems. Form which allows a better orientation of the stem, centered or in valgus, the point not pressed on the side wall, when the stem progresses in viscous cement, by analogy to the hydrodynamic point of view. It is obtained by different parameters of the Distal Ogive, lateral and medial.
Distributed Constraints
The constraints âare distributedâ if all the zones of an implant in contact with the osseous bed take part in stability and the resistance to penetration of the prosthesis.
Extractibility
Property of an implant not to be opposed geometrically to its extraction. This concept includes to equip the implant with the means of fixing of an extraction instrument, if possible standard, the instrumentation of extraction and finally a surgical technique of extraction.
Field of Osseous Vitality
I indicate by this expression, in statistical terms of constraints undergone by the bone, the intermediate field where the bone is reinforced or reconstituted, between the threshold of resorption by insufficient constraints and the higher threshold, threshold of resorption per excess of constraints.
Fixation Function
Exponential mathematical function added with the Pyramidal Base Form. The tiny thickening brought by this function allows a parameterized shift, into distal, of the distribution of the constraints between the stem and the bone. Fundamental function in the stems for medium reoperation like stem SLR Plus.
Form Factor
Not being creator of this expression, I just want to clarify its meaning used in this work: This number ranging between 0 and 1, indicates the rate of flatness of a rectangle, that is to say width/length. It is 1 for a circle or a square. For unspecified closed plane forms, that applies to the exinscrit rectangle, the length being parallel to the larger diameter.
Geometric Anchoring
Total concept, integrating the unit of my principles and allowing the application of my original and specific processes of creation of prostheses according to the type of implant.
Growth Center
It is about the point chosen like origin of the vector space common to all the sizes of a series of implants calculated by the Method of the Growth Factors. In the case of the nonanatomical femoral stems, this Center of Growth is defined by the meeting of the axis of the collar and the axis of the third proximal of the femur.
Growth Factors
They are multiplicative Factors defining the Growth of dimensions, of a size to the next, a way similar to the bank interests. The Method associates different Growth Factors with each vector from the basic vector space. I use this expression since 1981, when I formulated the first distribution of the sizes in a nonlinear but exponential way, for a project of recasting of the diameters of screwed cups of Polyethylene of Endler. (F: Facteurs de Croissance) (D: WachstumsFaktoren). I used these terms to name the project of knee AlloPro APS-GF of 1990. This expression, of Mathematical nature, does not have any common point with the Growth hormones, other biological agents appeared thereafter, nor the Growth Factors, (proteins), known since the Nobel Prize of Biology 1986.
Helicoid Space
Method of description which I developed to calculate an impact-screwed hybrid cup. In a first stage, all the points of contour and structure are defined and formulated geometrically in plans passing by the axis of the helix, and in a second phase, all the points undergo a rotation whose angle is controlled to their positions in Z on the axis. Details in 5.3.8.
Impaction Reserve**
Additional space in direct distal prolongation of the female part of any unit assembled by a junction of conical type, the âcatchâ and the reliability of the conical assembly requiring a progression or an additional impaction putting in elastic prestressing the two surfaces of the junction.
Implant Descriptor
A unique and unpublished software suite that I designed and wrote specifically for the description of orthopedic implants. It allows the simultaneous calculation of all sizes in a series, including the corresponding instruments.
The software includes an Implant Description program, a Parameter Database, a Coordinate Database, a Scaled Results Database, a Graphics Editor with representation and printing, and a Digital Machining Transmission Editor.
Multicone Junction
Expression which defines an extremely reliable impacted junction of conical type. This junction is made up of several steps whose conical junction is simultaneous. This division allows an adaptation of the junction the general shape of the implant, a thinning of the metal cup to confer him the desired elasticity and an increase overall thickness of Polyethylene, of massive insert or sandwich between cup and slidig seat. I had deposited the brand MULTICONE in 1997. Details in Patent 9.8.3.
Optimized Sizes
Calculated by the method of the Growth Factors, the implants of a series satisfy in an optimal and statistically equal way each patient, with constant variations expressed as a percentage of all their dimensions.
Parameter Base
The Parameter Base is an editor of data named and numbered data who allows to consult, capture, modify the data and their denomination under development, without entering the source program of description of the implant. Sources describing the geometry of the implants and defining each point, not comprising fixed metric or angular data. All are modifiable in the Base. The Parameter Base contains up to 1024 named and numbered parameters that all the programs of the system call by their number in the course of calculation.
Plane F T F
Expression (Femur - Tibia - Foot) which I propose to indicate the plan defined by the Femur, the bent Tibia with 90° and the Foot. This plan is mobile and independent in space relative to the fixed reference mark of the patient, and remains definite and unchanged when one makes swivel the whole of the lower extremity around the center of the femoral head. This plan contains the anterior curvature of the femur, with some rare exceptions. It is used as reference mark, including by restricted visibility, to set the antetorsion of the prosthetic neck, the antetorsion of the femoral rasp and its handle, and to direct the long curved stems of reoperation during the implantation.
Positive Derivates
This is the mathematical translation of the concept requiring all areas of any anchor stem cemented or uncemented to grow regularly from distal to proximal without restricting or parallelism. Symbolically, if they were illuminated of a quite distal point on the axis, any point on the surface should remain in the shadows. This is one of the Extractability conditions.
Proxicurvature
Expression which I use to describe the curvature forwards of the femoral metaphysis. This proximal curvature associated with the anterior curvature of the femur constitutes its general profile in S.
Pyramidal Base Form
Expression which identifies the principal body of the zone of anchoring of a femoral stem comprising still only rectilinear edges, the Base Form having already been adjusted by the Method of Thickness Corrections but yet not having been supplemented and having been refined by the other additional curves of the Polynomial of Calcar.
Results Base
Independent spreadsheet, posting the 400 Scaled Results for each size, numbered and named, grouped for all the sizes of a series of implants. A system of extraction allows the selection and the transmission of the only results useful for the numerical production and controls.
Spiral Reamer
New instrument, highly reliable, in the shape of spiral logarithmic curve in 3 dimensions, intended to prepare the medullary canal precisely in the shape of a curved cone to receive a cementless stem without cement with curvilinear axis.
Total Osseous Length
Expression which I use to indicate the length of the femur which must be reconstituted after an implantation. The Principle of Ascending Fitment allows the planning of it. It is the distance between the distal poles of the femoral condyles and the ideal center of the head of the femur, determined for example on the intact controlatéral femur.
Transition Curve
Mathematical representation of the progressive passage of a direction towards another direction on an implant, like the passage from the Anchoring Zone towards the neck. These curves can be three-dimensional to approach to a simulation of the orientation of the forces undergone in each point the bone, trabecular structure of the bone and crystalline component of the osseous cells.
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