title: Internal Rotation Stress Testing Improves Radiographic Outcomes of Type 3 Supracondylar Humerus Fractures.
abstract: BACKGROUND
  The purpose of this study was to determine if routine use of an intraoperative internal rotation stress test (IRST) for type 3 supracondylar humerus fractures will safely improve maintenance of reduction.
  
  
  METHODS
  An intraoperative protocol for type 3 supracondylar humerus fractures was adopted at our institution, consisting of fracture reduction, placement of 2 laterally based divergent pins, and then an IRST to determine the need for additional fixation with a medial column pin placed through a small open approach. Fractures treated with the prospective IRST protocol were compared with a retrospective cohort before adoption of the protocol (pre-IRST). The primary outcomes were differences in Baumann's angle, lateral humerocapitellar angle, and the rotation index between final intraoperative fluoroscopic images and radiographs at final follow-up. Secondary outcomes were complications such as iatrogenic nerve injury, loss of fixation, or need for reoperation.
  
  
  RESULTS
  There were 78 fractures in the retrospective cohort (pre-IRST) and 49 in the prospective cohort (IRST). Overall rotational loss of reduction (>6%), measured by lateral rotation percentage, and major rotational loss of reduction (>12%) were less common in the IRST cohort (6/49 vs. 27/78, P=0.007 overall; 0/49 vs. 8/78, P=0.02 major loss). There were no major losses of reduction for Baumann's angle (>12 degrees) in either cohort. There were 5 subjects in the pre-IRST cohort (6.4%) with a major loss of reduction of the humerocapitellar angle (>12 degrees) and none in the IRST cohort (P=0.16) Loss of proximal fixation with need for reoperation occurred in 3 fractures in the pre-IRST cohort, and none in the IRST cohort (P=0.28). There were no postoperative nerve injuries in either group.
  
  
  CONCLUSIONS
  Intraoperative IRST after placement of 2 lateral pins assists with the decision for additional fixation in type 3 supracondylar humerus fractures. This method improved the final radiographic rotational alignment, and was safely performed using a mini-open approach for medial pin placement.
  
  
  METHODS
  Level III-prospective cohort compared with a retrospective cohort.
authors.affiliation: Monroe Carell Jr Children's Hospital at Vanderbilt Medical Center, Pediatric Orthopaedic Surgery, Nashville, TN.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Bauer
authors.affiliation: Texas Scottish Rite Hospital for Children, Pediatric Orthopaedic Surgery, Dallas, TX.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Stutz
authors.affiliation: Monroe Carell Jr Children's Hospital at Vanderbilt Medical Center, Pediatric Orthopaedic Surgery, Nashville, TN.
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Schoenecker
authors.affiliation: Monroe Carell Jr Children's Hospital at Vanderbilt Medical Center, Pediatric Orthopaedic Surgery, Nashville, TN.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Lovejoy
authors.affiliation: Monroe Carell Jr Children's Hospital at Vanderbilt Medical Center, Pediatric Orthopaedic Surgery, Nashville, TN.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Mencio
authors.affiliation: Monroe Carell Jr Children's Hospital at Vanderbilt Medical Center, Pediatric Orthopaedic Surgery, Nashville, TN.
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Martus
mesh_terms: D001858:Bone Nails; D002675:Child, Preschool; D005260:Female; D005471:Fluoroscopy; D005593:Fracture Fixation, Internal / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D006810:Humeral Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006811:Humerus; D007432:Intraoperative Period; D008297:Male; D000070799:Open Fracture Reduction; D059348:Peripheral Nerve Injuries / Q000209:etiology; D011184:Postoperative Period; D011446:Prospective Studies; D012086:Reoperation; D012399:Rotation / Q000009:adverse effects; D013314:Stress, Mechanical