PitStop™ Subtalar Implant

The PitStop™ Subtalar Implant is a cannulated, biocompatible PEEK arthroereisis implant (endorthesis) that is press-fitted into the sinus tarsi to facilitate the correction of pes plano valgus deformity. It has an anatomical shape with lock-in flanges and two symmetrical flattened sides, and is inserted with a keyed insertion device. PEEK is radiolucent, so the implant is not visible on X-ray; two tantalum X-ray markers, one at each end, allow placement and depth to be confirmed under fluoroscopy.

The implant is inserted through a 1–3 cm lateral incision over the sinus tarsi, over a 1.6 mm guide wire, using a cannulated inserter.

Features

• Anatomical shape with lock-in flanges.
• Biocompatible, radiolucent PEEK.
• Two symmetrical flattened sides.
• Two tantalum X-ray markers for placement confirmation.
• Cannulated, press-fit insertion over a 1.6 mm guide wire with a keyed inserter.
• Seven sizes (10, 11, 12, 13, 14, 15 and 17), with matching trial implants.

Surgical technique

A 1–3 cm incision is made on the lateral side of the foot in the skin overlying the sinus tarsi, followed by blunt dissection with a haemostat to the level of the joint capsule.

The Viladot’s Lever is introduced through the sinus tarsi. The lever is moved slightly dorsal/medial and anterior/posterior to dilate the tarsal canal.

Once the talus is positioned on the calcaneus, the 1.6 mm Guide Wire is introduced into the axis of the sinus tarsi until the wire is felt on the medial aspect of the hindfoot. Accurate placement may be confirmed with fluoroscopy.

The Inserter is used to press-fit the Implant into the correct position with a pushing motion. Do not screw the Implant into place. X-ray markers at each end of the Implant help achieve the adequate depth under fluoroscopy. The corresponding flat surfaces of the Implant and Inserter handle are aligned parallel to the lateral talar process, which is at approximately 45° to the fibula and the plantar aspect of the foot on the lateral view.

Unscrew the Internal Holder to release the Implant and push with finger pressure to remove the Holder from the Implant.

Hindfoot mobility is assessed to verify adequate correction. The wound is closed according to surgeon preference.