CPT® Code 0335T

The sinus tarsi is a small anatomical channel located between the talus and calcaneus bones, which are critical components of the ankle joint. This space plays a vital role in stabilizing the ankle by housing various structures that contribute to its function. The insertion of a sinus tarsi implant is a surgical procedure aimed at addressing hyper-pronation of the foot, commonly referred to as flexible or mobile flatfoot. This condition involves an abnormal positioning of the talus bone over the calcaneus bone, leading to instability and improper movement of the subtalar joint. The sinus tarsi implant serves to correct this misalignment by repositioning the talus bone, thereby limiting excessive movement and providing stability to the hindfoot. The procedure involves a careful incision on the lateral side of the hindfoot, where the surgeon debrides the area of any fatty, fibrotic, and inflamed tissue, as well as nerve endings, to prepare for the implant. Various types and manufacturers of sinus tarsi implants exist, and the specific instrumentation and surgical techniques may vary. The overall goal of the procedure is to block unwanted forward, downward, and medial displacement of the talus, ultimately restoring proper foot mechanics and alleviating symptoms associated with flatfoot deformity.