Transcript activmotion - Medist Group

ACTIVMOTION
ACTIVMOTION
GENERAL THEORY
o Lower limb can present as an inward (varus) or outward (valgus) angulation.
 If mechanical axis is deviated, can get overloading and wearing of the
cartilage on one side.
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ACTIVMOTION
GENERAL THEORY
o Closing wedge osteotomy: External bone wedge removal (with an
osteotomy from the fibula).
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ACTIVMOTION
GENERAL THEORY
o Opening wedge osteotomy: Medial osteotomy of the tibia with the addition of
illiac crest or bone substitute to fill the bone gap.
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STRESS DISTRIBUTION IN A HEALTHY KNEE
o The medial tibial plateau supports
most of the weight bearing.
o During walking the stress is
predominantly anterior.
 Mechanical stress antero-medial.
o The ratio is about 70% of the load
on the medial plateau and 30% on
the lateral one.
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ACTIVMOTION
STRESS DISTRIBUTION IN A HEALTHY KNEE
o During the roll back process of the
knee (standing up, kneeling down…),
the body weight stress oscillates
between the posterior side of the tibial
plateau and the anterior side of the
plateau.
o Creates a postero-anterior stress
inside the knee.
o While standing up, the load goes from
80% on the back and 20% on the front
to 20% on the back and 80% on the
front.
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ACTIVMOTION
STRESS DISTRIBUTION IN A KNEE IN VARUS
In Varus :
o Mechanical axis passes outside from
the articulation.
o Medial compartment supports 100% of
the stress.
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STRESS DISTRIBUTION IN A KNEE IN VARUS
o Same impact as in a healthy knee.
o While standing up, the load goes from
80% on the back and 20% on the front
to 20% on the back and 80% on the
front.
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STRESS DISTRIBUTION IN A CORRECTED KNEE
o After osteotomy, +3° valgus.
o The ratio is about 60% of the load on
the lateral plateau and 40% left on the
medial one.
o During walking, the stress is still
predominantly anterior.
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STRESS DISTRIBUTION IN A CORRECTED KNEE
o Same impact as in a healthy knee.
o While standing up, the load goes from
80% on the back and 20% on the front
to 20% on the back and 80% on the
front.
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ACTIVMOTION
NEWCLIP’S TECHNOLOGY AS PROBLEM SOLVER
Problem :
o Post-op care too long (6 weeks) before putting
patients on load.
o Material may fail when putting on earlier load.
NCT solution :
Design an antero-medial plate for an optimal
answer to the biomechanics of the knee.
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ACTIVMOTION CONCEPT
Stress distribution on the plateau :
Lateral
2+1 system :
o 2 screws under the external
plateau. (Minimum 60% of the
load).
o 1 screw under the internal
plateau. (Maximum 40%of the
load)
o Antero-medial positioning to be
as close as possible to the
lateral stress.
INNOVATION MEANS MOTION
Medial
ACTIVMOTION
STRESS ABSORPTION
Dynamic stress inside the knee during walking :
o Antero-medial positioning of the
implant, to face the main
anterior forces during walking.
o Antero-medial positioning limits the tibial
internal-rotation of the distal fragment
and preserves the lateral hinge.
o Antero-posterior orientation of
the screws answering the rollback of the knee.
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STRESS ABSORPTION : SUMMARY
Problem :
Lateral
o Post-op care too long (6 weeks) before a
full weight bearing.
o Early weight bearing has to be possible.
NCT solution :
2+1 system & antero-medial positioning.
 Hold up to 2.5 T when static.
 Early weight bearing possible if no pain.
INNOVATION MEANS MOTION
Medial
ACTIVMOTION
NEWCLIP’S TECHNOLOGY AS PROBLEM SOLVER
Why should an implant supports that much of a load ?
Leverage effect :
o knee supports more than the weight
of the body (while standing up,
kneeling down…)
o Up to 8 times the weight of the
body.
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NEWCLIP’S CONCEPT : SOLVING THE PROBLEM
Problem :
o The lateral cortex has to remain intact, as bone
growth will start from it.
o To respect it, Pes Anserinus and MCL have to be
progressively released distally.
NCT solution :
o Antero-medial positioning with anatomical implant
based on bone-mapping technology.
o Compact and thin implant allowing the
recommended HTO surgical approach.
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ACTIVMOTION
HTO & ACL RECON
Problem:
o Classic treatment: ACL recon followed by HTO.
o Post-op care too long.
o Sport-medicine approach: both at the same time.
o No specific HTO implant on the market.
NCT/Orthofix solution : Specific implant
o Two variable angle screws.
o Specific positioning.
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SURGICAL APPROACH
o An 8-cm slightly oblique vertical incision
is made along the antero-medial surface,
running over the joint space down to
under the tibial tuberosity.
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SURGICAL APPROACH
o A single-plane incision is made through
the periosteum.
o The hamstring and the medial collateral
ligament (MCL) are retracted posteriorly.
o The larger the angular correction must
be, the more the hamstring and MCL
should be released distally.
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SURGICAL APPROACH
o Elevator used over the posterior surface
of the tibial and remain as protection.
o Clear the deepest part of the patellar
tendon down to its attachment onto the
tibial tuberosity, and protect it using a
retractor during the osteotomy.
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SURGICAL TECHNIQUE
o Incise upward toward the head of the
fibula and stop incision 5-10mm before
the lateral cortical area.
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SURGICAL TECHNIQUE
o Insert wedges of gradually larger
size until finding the appropriate one
(6-16mm).
o The angular correction is
maintained during osteosynthesis.
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SURGICAL TECHNIQUE
o Position the plate onto the anterointernal side.
o Proximal part of the plate runs parallel to
the osteotomy cut.
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SURGICAL TECHNIQUE
o Fit the first Ø3.5mm guide
under the osteotomy cut, then
start drilling using a Ø3.5mm
drill.
o Fit a second Ø3.5mm guide into
the polyaxial slot of the plate.
Adjust the drilling to the lateral
tibial plateau.
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SURGICAL TECHNIQUE
o The synthesis is complete when each
screw has been perfectly tightened.
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SURGICAL TECHNIQUE
o The MBCP bone substitute : 60% of hydroxyapatite and 40% of tricalcic
phosphate.
o Proposed in several sizes corresponding to the osteotomy correction (6 to
16mm).
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SURGICAL TECHNIQUE
o Cage as bone substitute holder.
o Avoid bone substitute migration.
o Optionnal.
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SUM UP
NCT innovation :
o 2 + 1 system.
2 screws under external plateau, 1 screw under internal plateau
for better weight bearing load care.
o Antero-internal positioning of the plate.
 orientation of the screws in the direction of the postero-anterior
roll-back induced stress.
o Low profile implant
 Doesn’t interfere with the hamstring ligaments, patient don’t feel it
under-skin.
o Combination of ACL reconstruction and HTO.
Specific implant that leave room for the tunnel.
INNOVATION MEANS MOTION
THANK YOU
Xavier Peiffert
International Product Manager
+33672689718
[email protected]