Q: What role does equinus play in AAF?
A: All of the panelists agree that equinus plays a significant role in the pathogenesis and progression of the deformity. Dr. Yu encourages careful examination of the contralateral extremity as it will help one determine whether the equinus is secondary or a primary contributing factor to AAF.
When clinical and radiographic evaluation confirms limited ankle joint dorsiflexion secondary to a tight gastrocsoleal complex, Dr. Grossman says one should proceed to perform appropriate treatment for an equinus contracture.
Equinus contracture breaks down the midtarsal joint and medial longitudinal arch, according to Dr. Rush. He also points out that equinus has a detrimental effect on the stabilizing effect of the posterior tibial tendon and peroneus longus on the medial longitudinal arch.
“The dampening of these important dynamic stabilizers leads to the talonavicular and naviculocuneiform faults one sees with progression of flatfoot deformity,” explains Dr. Rush.
When addressing equinus with conservative therapy, Dr. Catanzariti says one should emphasize posterior muscle group stretching.
Q: How should equinus be addressed surgically?
A: For those undergoing surgical treatment, the majority of the panelists agree that one should incorporate some form of posterior muscle group lengthening into the surgical plan.
“It has been well established that correcting the equinus with some type of posterior muscle group lengthening is crucial to establishing proper correction and alignment of the hindfoot,” points out Dr. Lee.
All of the panelists say they perform either a gastrocnemius recession or a tendo-Achilles (TAL) lengthening based on the clinical findings. Drs. Lee and Yu prefer gastrocnemius recession over the TAL procedure, citing faster rehabilitation and strength postoperatively without the risk or concerns of post-op Achilles tendon rupture. When it comes to the gastrocnemius recession, Dr. Catanzariti uses a 3 to 4 cm incision along the lower leg and Dr. Grossman opts for a Strayer-type procedure.
Dr. Rush prefers to perform the gastroc recession deep to the medial head of the gastrocnemius muscle belly from a medial approach. He says the sural nerve is protected at this level and it is a true muscle recession.
“There is little chance of overlengthening and the muscle heals very quickly and completely,” notes Dr. Rush.
If a TAL is indicated, Dr. Rush says a percutaneous lengthening is easier to perform and results in less weakness. Dr. Grossman concurs, noting that he performs a percutaneous three-step TAL. Dr. Catanzariti opts for a three incision, hemisection technique for Achilles tendon lengthening.
The percutaneous, three-incision approach does offer the advantages of performing the surgery with the patient supine whereas one typically performs gastroc recessions with the patient in a prone position, according to Dr. Yu.