title: Measurement of Nitinol Recovery Distance Using Pseudoelastic Intramedullary Nails for Tibiotalocalcaneal Arthrodesis.
abstract: BACKGROUND
  Tibiotalocalcaneal arthrodesis is a salvage procedure for patients with complex disease of the ankle and subtalar joints. Despite the clinical efficacy and mechanical advantage of intramedullary nails, complications, such as nonunion, are common. It may be possible to sustain compression in the face of bone resorption and implant loosening over the course of healing using a novel pseudoelastic intramedullary nail with an internal nitinol element.
  
  
  METHODS
  We identified 15 patients with average age of 54.7 years (range, 28-75 years) who had undergone a tibiotalocalcaneal arthrodesis using a pseudoelastic intramedullary nail. Serial radiographs were used to determine the amount and rate of nitinol element migration over the first 3 postoperative months.
  
  
  RESULTS
  Postoperatively, there was at least 2.38 mm of nitinol element migration proximally with mean of 5.58 mm (± 1.38), (range, 2.38-8.11 mm). Average follow-up time was 195 days (± 106.3), (range, 89-490 days). On average, 86% of the total recovered distance took place within the first 39.7 days (±10.03).
  
  
  CONCLUSIONS
  The nitinol element recovers distance when stretched intraoperatively and maintains moderate compression in response to bone resorption. Further studies are needed to assess if this increased compression lends itself to higher fusion rates than traditional intramedullary nails.
  
  
  METHODS
  Therapeutic, Level IV: Case series.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina (BJK, CEG, SDA, SGP).|North Carolina Orthopaedic Clinic, Durham, North Carolina (SGP).|Fuqua Business School, Duke University, Durham, North Carolina (SGP).
authors.forename: Beau J
authors.initials: BJ
authors.lastname: Kildow
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina (BJK, CEG, SDA, SGP).|North Carolina Orthopaedic Clinic, Durham, North Carolina (SGP).|Fuqua Business School, Duke University, Durham, North Carolina (SGP).
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Gross
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina (BJK, CEG, SDA, SGP).|North Carolina Orthopaedic Clinic, Durham, North Carolina (SGP).|Fuqua Business School, Duke University, Durham, North Carolina (SGP).
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Adams
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina (BJK, CEG, SDA, SGP).|North Carolina Orthopaedic Clinic, Durham, North Carolina (SGP).|Fuqua Business School, Duke University, Durham, North Carolina (SGP).
authors.forename: Selene G
authors.initials: SG
authors.lastname: Parekh
keywords: nitinol; pseudoelastic intramedullary nail; tibiotalocalcaneal arthrodesis