title: Internal fixation of unstable proximal humerus fractures with an anatomically preshaped interlocking plate: a clinical and radiologic evaluation.
abstract: BACKGROUND
  We evaluated the outcome after internal fixation of unstable or displaced proximal humerus fractures with a new fixed-angle implant.
  
  
  METHODS
  Prospective consecutive study with a 1-year clinical follow-up in 119 of 137 patients (87%; mean 68 +/- 15 years; 31 two-, 47 three-, and 41 four-part fractures).
  
  
  RESULTS
  One year postoperatively, the range of motion of the injured side demonstrated on average four-fifths of the function of the contralateral side. Ninety-five percentage of patients (n = 114) could dress themselves independently with no or only slight restriction. The mean disabilities of the arm, shoulder, and hand score was 21 (range, 0-62). The absolute and relative Constant score significantly (p < 0.001) improved from 56 +/- 18 (75% +/- 21%) at 6 months postoperatively to up to 65 +/- 18 (82% +/- 18%) at 12 months postoperatively. The initial fracture configuration did not have a significant influence on clinical outcome or complications. Twenty-six patients (22%) underwent a reintervention because of a clinical problem or subjective complaint, which led to total or relevant relief of problems in 23 patients (87%). Radiologic follow-up revealed a significant correction of the mean fragment angles (p < 0.001) postoperatively compared with initial postcrash radiographs. The precision of intraoperative reduction had a significant impact on the patient's disabilities of the arm, shoulder, and hand scoring (p = 0.02). A comparison of the last evaluable radiographs with the intraoperative intensifier images revealed a mean loss of reduction over time of </=2 degrees.
  
  
  CONCLUSIONS
  The angular stability of the fixed-angle interlocking plate could be proven radiologically in this clinical series. This fixation system seems to be a promising alternative in the treatment of displaced or unstable proximal humerus fractures. Clinical outcome can be further improved by avoiding certain minor errors in operative technique.
authors.affiliation: Orthopedic Department, Kantonsspital Bruderholz, Bruderholz, Switzerland.
authors.forename: Michael Tobias
authors.initials: MT
authors.lastname: Hirschmann
authors.forename: Volker
authors.initials: V
authors.lastname: Quarz
authors.forename: Laurent
authors.initials: L
authors.lastname: Audigé
authors.forename: Dietmar
authors.initials: D
authors.lastname: Ludin
authors.forename: Peter
authors.initials: P
authors.lastname: Messmer
authors.forename: Pietro
authors.initials: P
authors.lastname: Regazzoni
authors.forename: Thomas
authors.initials: T
authors.lastname: Gross
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001860:Bone Plates; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000379:methods*; D006801:Humans; D016015:Logistic Models; D008297:Male; D010147:Pain Measurement; D011859:Radiography; D016059:Range of Motion, Articular; D012784:Shoulder Fractures / Q000145:classification / Q000000981:diagnostic imaging / Q000601:surgery*; D013997:Time Factors