CPT® Code 0335T

1. Indications

The insertion of a sinus tarsi implant is indicated for the treatment of specific conditions related to foot mechanics and stability. The primary indications include:

• Hyper-pronation of the foot - This condition, also known as flexible or mobile flatfoot, involves excessive inward rolling of the foot during walking or standing, leading to instability and discomfort.
• Subtalar joint instability - The procedure is indicated for patients experiencing instability in the subtalar joint, which can result from improper alignment of the talus over the calcaneus.
• Foot deformities - Patients with structural deformities of the foot that contribute to abnormal gait patterns may benefit from this intervention to restore proper alignment and function.

2. Procedure

The procedure for the insertion of a sinus tarsi implant involves several critical steps to ensure proper placement and effectiveness. The steps are as follows:

• Step 1: Incision and Debridement - The surgeon begins by making an incision on the lateral side of the hindfoot, directly over the sinus tarsi. This incision allows access to the underlying structures. The area is then meticulously debrided to remove any fatty, fibrotic, and inflamed tissue, as well as nerve endings, to create a clean surgical field for the implant.
• Step 2: Introduction of the Lever - A blunt lever is introduced through the sinus tarsi and positioned under the neck of the talus bone. This lever is crucial for manipulating the position of the talus during the procedure.
• Step 3: Repositioning the Talus - The lever is advanced distally, which facilitates the supination of the hindfoot while simultaneously pronating the forefoot. This maneuver is essential for repositioning the talus head into its physiologic location, effectively correcting the hindfoot pronation.
• Step 4: Trial Implant Placement - Once the talus is properly positioned, trial implants are introduced into the sinus tarsi to assess the appropriate size needed for the final implant. This step is critical to ensure that the selected implant will provide the necessary support and correction.
• Step 5: Intraoperative Imaging - Intraoperative imaging techniques may be employed, often with simulated weight bearing, to verify the correct placement and degree of correction before the final sized implant is placed. This imaging helps ensure optimal outcomes and alignment.

3. Post-Procedure

After the insertion of the sinus tarsi implant, patients typically require specific post-procedure care to promote healing and ensure the success of the surgery. This may include recommendations for rest and limited weight-bearing activities to allow the surgical site to heal properly. Patients may also be advised to follow up with their healthcare provider for monitoring and assessment of the implant's effectiveness. Rehabilitation exercises may be introduced gradually to restore strength and mobility in the foot and ankle. It is essential for patients to adhere to the post-operative instructions provided by their surgeon to optimize recovery and achieve the desired outcomes from the procedure.