Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/14—Surgical saws
  • A61B17/15—Guides therefor
  • A61B17/154—Guides therefor for preparing bone for knee prosthesis
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/02—Surgical instruments, devices or methods for holding wounds open, e.g. retractors; Tractors
  • A61B17/025—Joint distractors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/14—Surgical saws
  • A61B17/15—Guides therefor
  • A61B17/154—Guides therefor for preparing bone for knee prosthesis
  • A61B17/155—Cutting femur
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/14—Surgical saws
  • A61B17/15—Guides therefor
  • A61B17/154—Guides therefor for preparing bone for knee prosthesis
  • A61B17/157—Cutting tibia

Definitions

• the object of the invention relates to the technical sector of medical sciences.
• the problem is to redo the anatomy of the joint, according to the biomechanical axes of the knee which must be respected.
• the preexisting deformation must be corrected so that the biomechanical axes of the knee are "normalized". It is considered that the corrected angular deviation must be reduced to 0 ° at the end of the intervention, whether it is a genu varum or a genu valgum.
• the tension of the lateral ligaments must be identical in flexion and extension. Otherwise the implants, even well positioned, are subject to excessive stress likely to lead to their loosening.
• the prosthetic implant after its installation, is as close as possible to the framework while respecting the cruciate ligaments and allowing bone cuts such that the year only removes what is strictly necessary.
• the method according to the invention is remarkable in that it comprises the following essential phases:
• FA mechanical axis of the limb.
• FD mechanical axis of the femur.
• AB tibial anatomical axis.
• the ancillary equipment essentially comprises, in combination, a tibial device composed of three organs, a trochlear device composed of two organs and a femoral device, composed of four elements, to allow cuts posterior and on the bearing surface.
• the tibial device comprises, a vice, an articulated connection and a tibial cutting plane guide.
• the trochlear device includes a viewfinder and a cutting plane guide.
• the femoral device comprises a so-called primary femoral viewfinder, a ligamentary tensor at 90 °, a plane guide of posterior posterior cuts and a plan guide of condylar support cuts.
• Figure 1 is a front view showing the tracing on the goniometry of the knee, reference points and axes.
• Figures 2, 3 and 4 are perspective views illustrating the different parts of the tibial device.
• Figure 5 is a perspective view showing the entire tibial device after assembly of its various components.
• Figure 6 is a perspective view of the trochlear sight.
• Figure 7 is a perspective view showing the trochlear sight positioned on the tibial device, instead of the axis passing through point (B).
• Figure 8 shows the use of the trochlear device.
• FIG. 9 is a perspective view, before assembly, of the elements of the primary viewfinder relating to the femoral device.
• Figure 10 is a perspective view illustrating the placement of the primary femoral viewfinder.
• Figure 11 is a perspective view corresponding to Figure 10, but after placement of the ligament tensor at 90o.
• Figure 12 is a perspective view similar to Figure 11, after placement of the posterior condylar section plane guide for the corresponding condylar section.
• FIG. 13 is a front view showing the adaptation of the planar guide of condylar sections of support, on a part of the primary femoral viewfinder, the apparatus being shown in tensioning position at 0 ° of flexion.
• Figure 14 is a view corresponding to Figure 13, after obtaining the optimum tension at 0 ° bending.
• Figure 15 shows the bone sections that were made.
• the apparatus for implementing the method for placing a knee prosthesis comprises in combination, a tibial device (I), a trochlear device (II) and a femoral device (III) ( Figures 5, 7 and 12). It should first of all describe the process necessary for preoperative planning so that, at the end of the intervention:
• the tension of the lateral ligaments is identical to 0 ° or 90 ° and that the knee is sufficiently stable in these two positions
• (A) is the middle of the bimalleolar forceps
• (B) is the middle of the tibial spines
• (D) is the center of the intercondylar notch
• (F) is the center of the femoral head
• (C) is a very important reference point for the positioning and correct positioning of the ancillary equipment. The construction of this point is explained below.
• point (C) On the axis (d) 10 cm from the joint space. These 10 cm are fixed arbitraireme ⁇ t for easy handling of the apparatus. Insofar as the corrected angular deviation at the start is compatible with the indication for a sliding arthroplasty, point (C) is constantly found on the diaphyseal axis of the femur: it suffices to measure its position relative to the mediodiaphyseal axis in order to be able to reconstruct it intraoperatively.
• the tibial device (I) essentially comprises a vice (1), an articulated connection (2) and a cutting plane guide (3) of the tibia.
• the vice (1) '( Figure 2) has a support frame (1a) equipped with a wheel (1b) for the axial control in approaching and moving away from the two parallel jaws (1c) and (1d) to grip bimalleolar forceps and therefore determine point (A).
• One of the jaws (1c) has a support profile (1c) cooperating with the tibia being capable of determining, in combination with a complementary support profile (2a) of the articulated connection (2), the inclination 7 °.
• the front face of the frame (1a) perpendicular to the jaws (1e) and (1d) has an overhanging vertical guide rail (1f) shaped in section for positioning and sliding the articulated connection (2).
• These two jaws (1e) and (1d) are equidistant from the vertical guide (1f), so that the articulated connection (2) is automatically in the middle of the bimalleolar forceps, whatever the curvature of the tibia.
• a groove (1g) is formed facially in the thickness of the rail (1f).
• the articulated liais ⁇ n (2) ( Figure 3) comprises a rigid rod (2b) capable of being engaged with free sliding in the U section of the vertical guide (1f) of the vice (1).
• the upper part of the rod (2b) is equipped with the support profile (2a) which determines, in combination with the support profile (1e) of the vice, the 7 ° of posterior inclination.
• Locking lugs (2c) and (2d) appear beyond the front face of the rod (2b) in the upper part and in the lower part for fixing the vice (1) and the cutting plane guide (3 ).
• the lug (2c) in particular the upper lug, can be positioned at different heights.
• the cutting plane guide (3) of the tibia comprises a guide rail (3a) capable of being engaged in free sliding on the external section of the rod (2b).
• the upper part of the guide rail (3a) has transversely overhanging, and in a symmetrical manner, two vertical branches (3b) in which are formed a plurality of superimposed horizontal grooves (3c) determining different cutting planes.
• a wider and deeper groove (3d) determines the trochlean cut.
• the rail (3a) is drilled right through in a plane perpendicular to said branches, for the passage of a rod (4) corresponding to point (B) which is the middle of the tibial spines.
• a mortise (3e) allows the positioning and the guiding of a trochlear sight (5) as indicated below.
• the lower part of the rail (3a) has a groove (3f) on the front.
• cutting plane guide (3) is also used for the trochlear cut.
• Figure 5 shows the assembly of the different elements (1), (2) and (3) composing the tibial device.
• the rod (2b) of the articulated connection (2) is engaged in the internal section of the rail (1f) of the vice (1), while the rail (3a) of the cutting plane (3) is engaged in free sliding on said rod (2b).
• the pins (2c) and (2d) project respectively through the grooves (1f) and (3f) and. cooperate with means blocking (6) to ensure the vertical positioning of the cutting plane (3) and the rod (2b).
• the trochlear device (II) comprises the viewfinder (5) and the cutting plane guide (3) described above.
• the viewfinder (5) is formed from a horizontal rectilinear rod (3a), one curved end (5b) of which receives, in a plane parallel to said rod, a support plate (5c) (FIG. 6).
• This plate (5c) has a fixing hole (5c1) corresponding to the point (C) previously calculated relative to the diaphyseal femoral media axis and 10 cm from the joint space as indicated above.
• a second complementary fixing hole (5c2) prevents any secondary displacement.
• the rod (5a) has transversely a groove (5a1) located 10 cm from the hole (5c1), to act as a reference relative to the cutting plane (3), after engagement of said rod (5a) in the mortise (3e ).
• the cutting plane guid ⁇ (3) is the same as for the tibial device, and is reassembled along the rod (2b) of articulated connection (2) to receive the rod (5a) of the viewfinder trochlean (5) ( Figure 7).
• These grooves or notches more pr ⁇ fo ⁇ des (3d) indicate the trochlear section plane which is therefore located strictly at 90 ° with respect to the mechanical axis of the tibia, therefore strictly to the tibial cuts ( Figure 8).
• the rod (5a) of the viewfinder (5) may have another reference groove (5a2) located 11 cm from the hole (5c1) for special cases where the femoral morphology would require it.
• the condylar device (III) ( Figure 9) includes a primary femoral viewfinder (7), a 90 ° ligament tensor (8), a posterior condylar sectional guide (9) .and a condylar sectional guide " support "(10).
• the primary femoral viewfinder (7) ( Figure 9) allows for exact condylar cuts. It is formed by a fixing base (7a) and two sticking pins (7b) and (7c). The base (7a), by a hole (7a1) is fixed on the couue trochlean, at point (C) being strictly applied to the anterior surface of the femoral shaft.
• the top face of the base (7a) has a guide tunnel (7d) equipped with a threaded rod (7k) which cooperates with the threaded bore of the axis (7b) for its axial displacement in translation to determine the approach of point (D).
• the axis (7b) receives at the end, a vertical guide tunnel (7e) equipped with a threaded rod (7f) cooperating with the threaded bore (7g) of the axis (7c) for its height adjustment .
• This tunnel (7e) is furthermore equipped with means (7i) ensuring the blocking in height in the desired position of the plane condylar posterior section guide (9).
• the base of the axis (7c) receives, in a perpendicular manner, a wick (7h) which is fixed in the center of the intercondylar notch ( Figure 10). It is emphasized that the viewfinder (7), in particular the axis (7b) makes an angle of 7 ° relative to the mechanical axis of the femur, these 7o having been determined arbitrarily to give an average physiological valgus.
• the 90 ° ligament tensor (8) is shaped to adapt very easily to the femoral viewfinder (7). It is established from a profiled support plate (8a) in horseshoe, with a central notch (8a1) to adapt and be applied to the. tibial cuts. This plate (8a) has axially at the notch (8a1), a squared rod (8b) capable of being freely mounted inside the vertical guide tunnel (7e) of the viewfinder (7) while being subject to the screw (7f) for adjusting the ligament tension at 90 ° flexion (figure 11).
• the base of the vertical rod (8b) has marks (8c) for the heights of the tibial plates.
• the posterior condylar section plan guide (9) ( Figure 12) makes it possible to determine the optimal size of the femoral prosthesis, acting as a template.
• This guide (9) is in the form of an inverted T whose vertical middle branch (9a) has a U-shaped section cooperating with the section external of the guide tunnel (7e) receiving the tensor (8).
• the branch (9a) receives several positioning holes cooperating with the means (7c) of the guide tunnel (7e).
• the horizontal wing (9b) of the guide (9) has, from each of its transverse edges, slots (9c) which determine the posterior condylar section plane.
• the guide (9) is adjusted in height relative to the graduations (8c) of the rod (8b) of the tensor (8) after determining the size of the femoral prosthesis, so that the deviation of flexion which must correspond to the extension difference correction made to the thickness of the femoral prosthesis.
• the guide plan of condylar sections of support (10) is fixed to the threaded rod (7k) of the femoral sight (7), the knee being at 0 ° of flexion (figure 13).
• the guide (10) also acts as a ligament tensor at 0 °, taking into account the presence of sharp points formed overflowing from its underside (FIG. 14).
• the viewfinder (7) can then be removed. It then suffices to place and seal the prosthetic parts. This viewfinder therefore made it possible to make bone cuts so that at the end of the intervention, the corrected angular deviation obtained was 0 °.

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• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Surgery (AREA)
• Dentistry (AREA)
• Biomedical Technology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Physical Education & Sports Medicine (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Engineering & Computer Science (AREA)
• Transplantation (AREA)
• Heart & Thoracic Surgery (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)

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• 1985
  • 1985-09-13 FR FR8513851A patent/FR2587198A1/fr not_active Withdrawn
• 1986
  • 1986-09-11 AU AU63711/86A patent/AU6371186A/en not_active Abandoned
  • 1986-09-11 EP EP19860905318 patent/EP0236397A1/de active Pending
  • 1986-09-11 WO PCT/FR1986/000304 patent/WO1987001579A1/fr not_active Ceased

Non-Patent Citations (1)

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