Surgeons face a variety of challenges and complications in bunion correction with a Lapidus procedure:
- Prominence of hardware creating patient discomfort
- Generation and maintenance of compression at fusion site to allow for proper healing
- Plantar, medial, and lateral gapping at the fusion site
- Preparation of bone surfaces to optimize contact surface area
The PHANTOM Lapidus Nail System was designed with these challenges in mind. The prominence of plates and screw heads was taken into careful consideration in the design of a zero-prominence implant. This design was intended to eliminate pain associated with hardware prominence of traditional plating systems. Being intramedullary, this nail is capable of accepting greater forces across the fusion site and limits migration during healing which may allow for earlier weight bearing when compared with competitive devices. The intramedullary design is intended to minimize disruption to the periosteum and preserve blood flow which traditional plating systems may suffocate.
The Nail utilizes crossed screw fixation both distally and proximally which has been shown to generate greater compressive force than screws placed through a plate. The Nail exerts a proportionate amount of force in all directions resisting recurrent hallux valgus (associated with non-anatomically contoured medial plating systems) and plantar gapping (associated with dorsal plating systems). The system includes instrumentation to facilitate drilling and nail placement ensuring accurate positioning of the nail in a highly vascularized environment.
Finite element analysis (FEA) was used to determine the appropriate amount of compression for the first TMT joint. The system includes a calibrated driver which allows surgeons to determine when the nail has achieved this ideal compression amount.
In order to accommodate varying patient anatomies and for use with Paragon 28's PRESERVE Lapidus Graft, nails are offered in lengths of 38-60 mm (2 mm increments). Threaded pegs are provided to allow for bicortical fixation and threading through the nail. A locking screw is used in the most dorsal hole of the nail to further lock in the construct and prevent bony in-growth through the nail.
Paragon 28 is grateful for the significant contributions Dr. Thomas Chang, DPM, Dr. James Clancy, DPM, Dr. Michael Houghton, M.D., and Dr. Thomas San Giovanni, M.D., made as surgeon designers of this system.