Why HyProCure®?

Sinus tarsi devices are not all the same!

What makes HyProCure® so special?

Classification of Extra-Osseous TaloTarsal Stabilization Devices

Extra-Osseous Talotarsal Stabilization Devices: A New Classification System. Vol. 51, No. 5, p. 613-622, 2012.

Classification of Extra-Osseous TaloTarsal Stabilization Devices

– Type I – Cylinder and Cone designs• device is placed into the lateral/sinus portion of the sinus

tarsi• laterally anchored.

– Type II – device is placed into the central portion of the sinus- • medially anchored deep into the canalis portion of the sinus

tarsi.

Differences• Device design• Placement/Position within the sinus tarsi• Soft tissue anchor mechanism• Angle of insertion/placement• Functional/Biomechanical• Device composition

Type I sinus portion of the

sinus tarsi

Type IIsinus and canalis.

Type I EOTTS devices are inserted

lateral to medial

They are inserted until the leading/medial edge touches the

bisection of the talus. Placed in the sinus portion of the sinus

tarsi.

Type IINotice the angle of insertion.

HyProCure is inserted anterior-lateral-distal

toposterior-medial-proximal

Calcaneal Placement

Type I Type II

Lateral to Medial Oblique & deep

The Problem with Type I

• Since they only fit into the outer portion of the sinus tarsi

• There is direct impact against the stent with every step taken

• Eventually the stent becomes dislodged and has to be replaced.

• These are not biomechanically friendly.

Think about what is occurring during the gait cycle.

TTJ Supination

Talus externally rotates – pulling the lateral process posteriorly.

Think about what is occurring during the gait cycle.

TTJ Pronation

Talus internally rotates – forcing the lateral process anteriorly smashing into the arthroereisis device with every step taken.

The most stable area of the sinus tarsi is in the canalis

The reason why there are thick stronger ligaments in the lateral sinus portion of the sinus tarsi is to “check” any excessive amount of internal rotary force of the talus on the tarsal mechanism.

Let’s Think About This!

If the canalis portion of the sinus tarsi is the most stable…

…doesn’t it make sense that this is the most important area to anchor our talotarsal stabilization device?

What is the direction of the sinus tarsi?

It isn’t lateral to medial!

Anterior-distal-lateral to

Posterior-proximal-medial

Let’s Take a Closer Look at the undersurface of the Talus and HyProCure

What/where is the most important area to stabilize the talus on the

tarsal mechanism?This is about the most important question that can be

asked as this is what we are trying to achieve.

TTJ’s Axis- This is the exact area where the talus MUST be prevented from slipping off its position on the posterior aspect of the calcaneus.

So, how do the various stent do this?

Type I Devices

• The tip of the device can enter into this area of the sinus tarsi and therefore stabilize it.

• However, remember that the majority of forces are acting laterally so that that it is possible for the type I device to “wiggle” out of place and partially detach and lose its function to stabilize the axis.

Type II HyProCure

• The tapered portion of HyProCure is the real work-horse as this the portion that prevents the talus from dislocating on the tarsal mechanism.

• The talus glides over HyProCure.

Difference between lateral-medial placement and oblique orientation of HyProCure.

HyProCure - Anatomy

• Threaded portion• Tapered portion• Lateral stabilizer

HyProCure – Threaded Section

• The anchoring portion of HyProCure is the medial section.

• Although this is not a “screw” as HyProCure’s threads do NOT engage into the walls of the sinus tarsi.

• Their function is to allow tissue ON-GROWTH to medially anchor HyProCure into the sinus tarsi.

HyProCure – Tapered Section

• The stabilizing portion of HyProCure is the middle tapered section.

• It is smooth so that there is equal pressure action on the talus to lessen any potential of bone deformation.

HyProCure – Lateral Section

• Primary function is to assist in lateral stability of the lateral process

• Grove within the “head” of HyProCure allows also for tissue on-growth to also laterally anchor HyProCure for additional stability.

Tissue Adherence

In-growth On-growth• Tissue incorporates into the

device.• Not only does the tissue

completely surround the device it grows internally.

• Sounds good except if the device has to be removed these tissue are removed as well.

• Tissues grow onto the device but not deep into the device.

• Advantage is that if the device has to be removed the tissues are not.

HyProCure’s unique design allows for multiple points of peripheral soft tissue on-growth by not in-growth.

Does it make a difference what material makes up the device?

You bet it does!

TaloTarsal Stabilization

• Bone• Silicone• High Molecular Weight Polyethene• Combination Titanium and Polyethene• Titanium• Poly-lactate Acid (absorbable)

Device Material

• Bone – gets absorbed, not reliable, not strong enough• Silicone – not strong enough, fragments, silicone shards,

not reliable.• Polyethene – not strong enough, fragments, not reliable.• Polylactate – absorbs, temporary, loss of correction.

EOTTS Device - Titanium

• Material of choice• Stronger than bone• Least reactive material implanted into the body• Does oxidize and can turn tissues a darker color

however this has never been shown to become a problem.

• Patients can still have MRI, CT, etc., without fear

• Does not set off a metal detector

Titanium and Tissue Adherence

• Titanium has extremely small micropores that allow partial tissue attachment.

• If a HyProCure device has to be remove, twist it 360 degrees which frees-up the tissue attachments.

Conclusion:

Why HyProCure?

HyProCure has the best anatomic design

& biomechanical function.

“Changing Lives, One Step at a Time”