Many surgical techniques for treating chronic posttraumatic hyperextension instability of the proximal interphalangeal (PIP) joint involve exploration of the PIP joint, often leading to stiffness in an already traumatized joint. This article outlines the indications, contraindications, surgical technique, and postoperative management for a modified flexor digitorum sublimis tenodesis that utilizes 2 small incisions, a slip of flexor digitorum sublimis, a suture anchor, and temporary pinning of the PIP joint, while avoiding violation of the PIP capsule.