title: Comparison of First- and Second-Generation Fixed-Bearing Total Ankle Arthroplasty Using a Modular Intramedullary Tibial Component.
abstract: BACKGROUND
  This series reviews the clinical and radiographic outcomes of patients who underwent total ankle replacement (TAR) using first- and second-generations of a modern fixed-bearing prosthesis utilizing a modular intramedullary stem.
  
  
  METHODS
  A consecutive series of first- and second-generation primary TARs with modular intramedullary stems were identified. Clinical outcome data were collected prospectively--including visual analog scale for pain, American Orthopaedic Foot & Ankle Society hindfoot-ankle, Short Musculoskeletal Function Assessment, and Short Form-36 scores. Preoperative coronal plane deformity and correction of deformity after TAR were assessed. Complications, subsequent procedures, and failure rates were compared. A total of 193 first- and 56 second-generation patients were identified with a mean follow-up of 3.7 and 2.1 years, respectively.
  
  
  RESULTS
  Clinical outcome data reflected significant improvements at 1 year postoperatively, and improvements were maintained at 2-year follow-up for each group. Improvement in visual analog scale scores were significantly better in the second-generation group at 1 year postoperatively, but this was not maintained at 2 years. Mean coronal tibiotalar angles for ankles with preoperative varus or valgus deformities were significantly improved. Correction was maintained until final follow-up, with no significant differences in deformity improvement between groups. The rate of reoperation at 2 years postoperatively on the affected foot or ankle subsequent to the index ankle replacement for patients in the first-generation group (18.5%) was higher compared to the second-generation group (15.9%), but the time until reoperation was not statistically significant (P = .376). The implant failure rate was higher in the first-generation group (6.0%) compared to the second-generation group (2.6%) at 2 years postoperatively, but the time until failure was not significantly different (P = .295).
  
  
  CONCLUSIONS
  Patients who underwent TAR with a first- or second-generation fixed-bearing prosthesis with an intramedullary tibial component demonstrated significant improvements in all measures of pain and function with sustained improvements in coronal plane alignment. The second-generation prosthesis demonstrated slightly better improvements at 1 year and was associated with lower reoperation and implant failure rates.
  
  
  METHODS
  Level II, comparative series.
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA john.lewis@duke.edu.
authors.forename: John S
authors.initials: JS
authors.lastname: Lewis
authors.affiliation: Duke University School of Medicine, Department of Biostatistics and Bioinformatics, Durham, NC, USA.
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Green
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Samuel B
authors.initials: SB
authors.lastname: Adams
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Easley
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: DeOrio
authors.affiliation: Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Nunley
mesh_terms: D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000601:surgery; D058737:Arthroplasty, Replacement, Ankle / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D063868:Patient Outcome Assessment; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data; D064232:Visual Analog Scale
keywords: INBONE; ankle arthritis; ankle arthroplasty; total ankle replacement