Posterior Tibial Tendon Dysfunction The Role of Extra-Osseous TaloTarsal Stabilization Michael E. Graham, D.P.M., F.A.C.F.A.S. Inventor, HyProCure Founder: GraMedica, Graham International Implant Institute Private Practice: Shelby Township, Michigan, USA
Why?• We need to take a critical look at this very common condition.• We need to take action to prevent the progression of the disease progression.• Why does PTTD occur?• What are the best viable treatment options.
Patient presents with symptoms or concerns due to excessive rearfoot motion. Is this normal or is this pathologic? This foot has a mechanical disadvantage.
This excessive pronatory motion has beennamed as the most common etiology of the majority of foot & ankle conditions.
This patient was not born with her foot looking like this. This is the result of years of “conservative” treatment. Her specialists thought that they were “doing no harm” in reality they have caused great harm.
Normal TaloTarsal Alignment • Talus is sitting on top of the calcaneus. • The articular facets are aligned. • The two bones are balanced. • Sinus tarsi is in its natural open position.
TaloTarsal Mechanism Talus acting on the articulations with the calcaneus and navicular Talus Navicular Facet Calcaneus Posterior FacetMiddle & Anterior Facet
TaloTarsal Motion: You cannot talk about the motion of the subtalar joint withoutalso discussing the talonavicular joint as even though there are 4 separate anatomical joints they function as one.
The articulations of the talus on the tarsal mechanism With the TTM inNEUTRAL POSITION www.hyprocure.com
Malposition of the posterior articulation results in malposition ofthe middle/anterior facets and also talonavicular joint. www.hyprocure.com
Ligament Support • Ligaments function as a supportive tissue to assist in the alignment of the osseous structures. • The alignment of the talotarsal mechanism is so important that there is a major complex of supporting ligament attachments.
Remember • The talus is the only “foot” bone that does not have a tendon attachment. • Its motion is dependent on the articular facets of the tarsal mechanism, capsular and ligament tissues.
Ligament Contains mechanicoreceptors to send a signal to the CNS which in response sends a signal to the muscle to contract to provide support to the joint.
Tibialis Posterior Muscle/Tendon Complex • Functions to supinate the foot. • Strongest supinator of the mid-foot • Has to over-come pronatory forces to lift the foot for toe- off.
Additional Important SupportiveStructures to Tibialis Posterior Function• Tendon sheath- helps the tendon glide behind the medial malleolus and within the flexor retinaculum.• Flexor retinaculum- keeps the tendon aligned for optimum function.
Tibialis Posterior Tendon Insertions Primary insertion in the navicular tuberosity and secondary insertions plantar aspects of the medial column of the foot.
THIS IS VERY IMPORTANT Tibialis posterior inserts into themedial/plantar aspect of the mid-footto supinate the medial column at late mid-stance to toe off.
Tibialis Posterior Tendon Dysfunction Why do good tendons go bad?
There is an underlying etiology to every symptom.The goal is not to solely treat the symptom but to eliminate the cause.
People are not born with pathologic tendons. At birth our tendons are very healthy.
However, if the talotarsalmechanism is not properly alignedas a child a good healthy posteriortibial tendon will slowly but surely continue to become diseased.
Let’s take a closer look at thetalotarsal mechanism and how it can significantly implant the function of tibial posterior
Normal TTMRemember- talus is sitting on top ofthe calcaneus, sinus tarsi is open, andthere is a normal cyma.The articular facets of the talus areperfectly aligned with the articularfacets of the calcaneus and navicular.
Abnormal TTMThe talus slid off its normal positionoff of the calcaneus. The articularfacets are not aligned. Sinus tarsi ispartially collapsed. The talus isplantarflexing on tarsal mechanism.Excessive abnormal forces are actingon the medial column of the foot.
Navicular DropResting BalancedStance TaloTarsal JointThe navicular is forced out of position due to the excessive abnormalforces from the talar displacement. This is a dynamic deformity occurringwith every step taken.
Navicular Drop• Imagine that during the walking cycle with no weight on the talotarsal mechanism- it is in alignment. At heel strike the talus quickly displaces on the tarsal mechanism, it partially dislocates anteriomedially to push the navicular down which is forced to “drop”.
Navicular Drop • Not only is the navicular pushed forward it is also forced plantar. • The talus is responsible to transfer the entire weight of the body from the leg above to the foot below.
Use your imagination.Do you think will have a negative effective on the posterior tibial tendon? Withevery step excessive abnormal forces are acting on the posterior tibial tendon.
Effect of navicular drop to the tibialis posterior tendon
Effect of navicular drop on tibialis posterior.The poor tendon doesn’t have a chance, think about the damage being inflictedthousands of times a day, day after day, week after week, month after month, yearafter year, decade after decade.
Talus slips off the calcaneus resulting in partial dislocation of the talotarsal mechanism. This forces the navicular to eventually “drop”. Tibialis posterior tendon is immediatelystrain/elongated which decreases blood flow within the tendon.The strain is continually placed on the tendon until more and more damage ensues.
What are the treatment options for these patients? • Nothing? • Orthotics? • Injections? • Oral meds.? • External braces? • Calcaneal osteotomy? • Talonavicular Arthrodesis? • Triple Arthrodesis?
Foot Orthotics• Cannot stabilize the talus• Cannot prevent the excessive talar motion• Have to be used in shoes• Have to find shoes to fit the device• Not covered by most insurance companies• Gives a false sense of correction• Provides only minimal support• The list goes on …..
Medial Displacement Osteotomy? Just doesnt make a lot of sense.There isn’t a deformity within thecalcaneus its above…the partialdisplacement of the talus on theTarsal mechanism-remember.
Extra-Osseous TaloTarsal Stabilization Why Not?• It addresses the deformity• Completely reversible• Not dependent on external factors-shoes• Can be performed on a wide age-range of patients• Fast recovery, dependable results
The goal• Early ambulation• Effective correction• Least amount of down time• Least amount of complications• Return to normal function• Do no harm• Why wait until they need a major rearfoot reconstructive procedure?
Fix the cause,don’t ameliorate the symptom(s).
HyProCure®• FDA 510(k) Sept 2004, CE 2006• Routinely used in pediatrics, adults, geriatrics.• Can be a stand alone or used in conjunction with other surgical procedures (depending on secondary deformities)• Thousands have been successfully placed globally• Placed in athletes of almost every sport
Extra-Osseous TaloTarsal Stabilization• When orthotics don’t give enough correction• Prior to more radical rearfoot surgery• Think• E.O.T.T.S.• There are limitations…foot must be flexible.
HyProCure Please visit:www.hyprocure.com For further information