title: Midshaft clavicle fractures with associated ipsilateral acromioclavicular joint dislocations: Incidence and risk factors.
abstract: BACKGROUND
  Simultaneous ipsilateral clavicle and acromioclavicular (AC) joint injury have been infrequently reported in the literature at this time. The purpose of this study was to assess incidence as well as assess risk factors for this dual injury pattern.
  
  
  METHODS
  We performed a retrospective review of a prospectively collected database (Level III evidence), evaluating 383 adult patients without previous shoulder girdle injury or trauma with a minimum 1-year follow-up who sustained a displaced diaphyseal clavicle fracture. All patients in the study underwent either nonoperative management or surgical reduction and stabilization of a diaphyseal clavicle fracture with a plate and screw construct. Study subjects were followed with serial radiographs. Clavicle and shoulder radiographs, as well as chest radiographs and contralateral films in questionable cases, were used to assess for acromioclavicular joint injury in both operative and nonoperative groups. Additional data was collected on concurrent injuries, patient demographics, fracture characteristics, fixation techniques, surgical/post-operative data, and operative or nonoperative treatment.
  
  
  RESULTS
  We found that 13/183 (7.1%) of patients undergoing fixation of a diaphyseal clavicle fracture had an ipsilateral AC joint injury, while 13/200 (6.5%) of patients undergoing conservative management had an ipsilateral AC joint injury. Critical analysis of the data revealed that presence of ipsilateral scapular body fractures, and a likely incidental association with superior plating fixation, were associated with an increased rate of this injury pattern.
  
  
  CONCLUSIONS
  Ipsilateral clavicle fracture and AC joint injury is much more common than traditionally believed, with an incidence of 6.8% overall. It is unknown how the presence of an associated AC injury influences outcome, as AC injury was not universally symptomatic.
authors.affiliation: Department of Orthopaedic Surgery, Doctor's Hospital, Columbus, OH, USA. Electronic address: drbentaylor@gmail.com.
authors.forename: Christina
authors.initials: C
authors.lastname: Ottomeyer
authors.affiliation: Department of Orthopaedic Trauma, Grant Medical Center, Columbus, OH, USA.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Taylor
authors.affiliation: Department of Orthopaedic Trauma, Grant Medical Center, Columbus, OH, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Isaacson
authors.affiliation: Department of Orthopaedic Trauma, Grant Medical Center, Columbus, OH, USA.
authors.forename: Lara
authors.initials: L
authors.lastname: Martinez
authors.affiliation: Department of Orthopaedic Surgery, Doctor's Hospital, Columbus, OH, USA.
authors.forename: Pierce
authors.initials: P
authors.lastname: Ebaugh
authors.affiliation: Department of Orthopaedic Trauma, Grant Medical Center, Columbus, OH, USA.
authors.forename: Bruce G
authors.initials: BG
authors.lastname: French
mesh_terms: D000173:Acromioclavicular Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D002968:Clavicle / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D004185:Disability Evaluation; D005260:Female; D005593:Fracture Fixation, Internal / Q000379:methods*; D017102:Fracture Healing; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012307:Risk Factors; D012783:Shoulder Dislocation / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D014193:Trauma Centers; D016896:Treatment Outcome; D014481:United States; D055815:Young Adult
keywords: Ac; Acromioclavicular joint; Acromion; Clavicle fracture; Midshaft clavicle; Scapula; Scapular body; Shoulder girdle