Early Results Show DynaNail Mini Maintains Compression After Surgery

MedShape Inc.., developer of orthopedic devices using nickel titanium (NiTiNOL), has reported on the initial clinical outcomes with the DynaNail Mini Fusion System for subtalar fusion procedures. First used clinically under a limited market release in 2019, the DynaNail Mini has been implanted by over 50 orthopedic surgeons in over 50 hospitals across the United States. The DynaNail Mini features MedShape’s patented superelastic nickel titanium (NiTiNOL) technology and is the first device designed for subtalar fusion that offers maintained active compression post-surgery. 
 
Compression across the joint is important not only for ensuring the bones remain tightly apposed, but also in promoting the appropriate bone healing response.¹ Screws currently represent the primary surgical treatment option in subtalar fusion procedures, but these devices are unable to hold compression following surgery when bone resorption and joint settling inherently occur. The DynaNail Mini features an internal NiTiNOL Compressive Element that allows for dynamic compression to be maintained post-surgery. The superelastic properties of NiTiNOL enable the DynaNail Mini to automatically adapt and respond to changes in the joint throughout the healing process while also allowing for immediate dynamization upon weight-bearing. Furthermore, the device includes two transverse locking screws to help provide additional joint stability and improved fixation.
 
Sam Adams, M.D., (Duke University) was one of the first surgeons to implant the DynaNail Mini and has performed numerous surgeries with the longest follow-up results now at nine months. According to Dr. Adams, “The DynaNail Mini with its internal NiTiNOL element is an unrivaled device for subtalar fusion. Its maintained post-operative compression and transverse locking screws give me the confidence that I can achieve successful outcomes where traditional compression screws might fail. To date, my Mini patients have all successfully fused with no complications. The device is truly a gamechanger!”
 
The DynaNail Mini has been used to address a number of different pathologies and indications including revisions of prior failed fusions, calcaneal fractures, and severe deformity. Most notably according to the literature, patients who have a prior ankle fusion have shown to be significantly more at risk for subtalar non-union.² Another early adopter, Terrence Philbin, DO (Orthopedic Foot & Ankle), is seeing successful outcomes with the DynaNail Mini.
 
“Overall, I have been pleased with the results I have achieved with the DynaNail Mini to treat classically challenging indications,” said Dr. Philbin. “In particular, I have implanted the DynaNail Mini in two patients with prior ankle fusions. At six and three months post-surgery, both patients have shown successful bony union on CT and are doing well clinically. I look forward to expanding my indications for use with this innovative product.” 
 
The DynaNail Mini joins its predecessor, the DynaNail TTC Fusion System, in MedShape’s growing NiTiNOL product portfolio that also includes the DynaClip Bone Fixation System. Commercially available since 2013, the clinical power of the DynaNail to treat complex hindfoot pathologies in high-risk patient populations has been demonstrated in numerous peer-reviewed articles^3,4 suggesting the potential clinical utility of the DynaNail Mini for other foot and ankle applications.
 
“We are very pleased with the market acceptance and clinical results observed so far for the DynaNail Mini,” said Kurt Jacobus, Ph.D., MedShape Inc. president and CEO. “Building off the momentum of the DynaNail TTC System, the Mini is poised to be another revolutionary device in joint fusion.”
 
The DynaNail Mini Fusion System is now available in full market release for subtalar fusion in a variety of diameter and length offerings.
 
MedShape Inc. is a privately held medical device company working to develop and commercialize a portfolio of surgical solutions that uses its patented advanced functional material technologies to address the increasing demand for improved joint fusion, soft tissue repair and musculoskeletal trauma products in the foot and ankle.

References 
¹ Dupont KM, Shibuya N, Bariteau JT. Tibiotalocalcaneal Arthrodesis with Intramedullary Nails – Mechanobiological Background and Evolution of Compressive Technology. Global J of Orthopedics Research, 2019. 1(5): 1-8. 
² Zanolli DH, Nunley JA, Easley ME. Subtalar Fusion Rate in Patients With Previous Ipsilateral Ankle Arthrodesis. Foot & Ankle Int, 2015. 36(9): 1025-1028. 
³ Steele JR, Easley ME, Nunley JA, Adams SB, et al. Comparison of Tibiotalocalcaneal Arthrodeses Using a Sustained Dynamic Compression Nail Versus Nondynamized Nails. Foot & Ankle Spec, 2019 (in press: doi: https://journals.sagepub.com/doi/10.1177/1938640019843332).
⁴ Ford SE, Kwon JY, Ellington K. Tibiotalocalcaneal Arthrodesis Utilizing a Titanium Intramedullary Nail With an Internal Pseudoelastic Nitinol Compression Element: A Retrospective Case Series of 33 Patients. J Foot Ankle Surg, 2019. 58(2): 266-272.