title: The use of a ti-ni shape memory alloy ring bone fixator during the retrograde nailing of supracondylar femoral fractures.
abstract: OBJECTIVE
  To identify the effects of using a Ti-Ni shape memory alloy ring shaped bone fixator (SMA-rBF) during the retrograde nailing of supracondylar femoral fractures.
  
  
  METHODS
  The authors reviewed 25 patients with a supracondylar femoral fracture treated by retrograde intramedullary nailing with or without SMA-rBF (group S, 12/25; group N, 13/25). Radiological measurements of angular deformity were performed and functional assessments were made using the Sanders grading system.
  
  
  RESULTS
  All fractures healed after an average of 12.2 weeks (range, 9-15 weeks) in group N and after 11.6 weeks (range, 10-13 weeks) in group S (p=0.351). The mean angle of coronal angular deformity was valgus 0.8° (range, varus 2.3°-valgus 4.5°) in group N and valgus 0.7° (range, varus 1.0°-valgus 2.4°) in group S (p=0.892). The mean angle of sagittal angular deformity was 1.0° in extension (range, flexion 3.2°-extension 3.1°) in group N and 0° (range, flexion 2.1°-extension 1.2°) in group S (p=0.022). However, functional grading evaluations revealed no differences between the two groups.
  
  
  CONCLUSIONS
  When reduction of a distal femoral fracture with retrograde nailing was difficult additional mini-open reduction and fixation with a ring shaped SMA did not delay or prevent bony union and resulted in good postoperative alignment.
authors.affiliation: Department of Orthopaedic Surgery, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Soo
authors.initials: HS
authors.lastname: Han
authors.forename: Dae-Ha
authors.initials: DH
authors.lastname: Kim
authors.forename: Seung-Baik
authors.initials: SB
authors.lastname: Kang