title: Effects of hook plate on shoulder function after treatment of acromioclavicular joint dislocation.
abstract: BACKGROUND
  Internal fixation with hook plate has been used to treat acromioclavicular joint dislocation. This study aims to evaluate the effect of its use on shoulder function, to further analyze the contributing factors, and provide a basis for selection and design of improved internal fixation treatment of the acromioclavicular joint dislocation in the future.
  
  
  METHODS
  A retrospective analysis was performed on patients treated with a hook plate for acromioclavicular joint dislocation in our hospital from January 2010 to February 2013. There were 33 cases in total, including 25 males and 8 females, with mean age of 48.27 ± 8.7 years. There were 29 cases of Rockwood type III acromioclavicular dislocation, 4 cases of type V. The Constant-Murley shoulder function scoring system was used to evaluate the shoulder function recovery status after surgery. Anteroposterior shoulder X-ray was used to assess the position of the hook plate, status of acromioclavicular joint reduction and the occurrence of postoperative complications.
  
  
  RESULTS
  According to the Constant-Murley shoulder function scoring system, the average scores were 78 ± 6 points 8 to 12 months after the surgery and before the removal of the hook plate, the average scores were 89 ± 5 minutes two months after the removal of hook plate. Postoperative X-ray imaging showed osteolysis in 10 cases (30.3%), osteoarthritis in six cases (18.1%), osteolysis associated with osteoarthritis in four cases(12.1%), and steel hook broken in one case (3%).
  
  
  CONCLUSIONS
  The use of hook plate on open reduction and internal fixation of the acromioclavicular joint dislocation had little adverse effect on shoulder function and is an effective method for the treatment of acromioclavicular joint dislocation. Osteoarthritis and osteolysis are the two common complications after hook plate use, which are associated with the impairment of shoulder function. Shoulder function will be improved after removal of the hook plate.
authors.affiliation: Department of Orthopaedics, The Second Affiliated Hospital of Suzhou University Suzhou, Jiangsu, China ; Department of Orthopaedics, Jiangyin Traditional Chinese Medical Hospital Jiangyin, Jiangsu, China.
authors.forename: Chang-Hong
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Orthopaedics, The Second Affiliated Hospital of Suzhou University Suzhou, Jiangsu, China.
authors.forename: Qi-Rong
authors.initials: QR
authors.lastname: Dong
authors.affiliation: Department of Orthopaedics, Jiangyin Traditional Chinese Medical Hospital Jiangyin, Jiangsu, China.
authors.forename: Rong-Kui
authors.initials: RK
authors.lastname: Zhou
authors.affiliation: Department of Orthopaedics, Jiangyin Traditional Chinese Medical Hospital Jiangyin, Jiangsu, China.
authors.forename: Hua-Qing
authors.initials: HQ
authors.lastname: Zhen
authors.affiliation: Department of Orthopaedics, Jiangyin Traditional Chinese Medical Hospital Jiangyin, Jiangsu, China.
authors.forename: Ya-Jun
authors.initials: YJ
authors.lastname: Jiao
keywords: Acromioclavicular joint; dislocation; function; hook plate; osteoarthritis; osteolysis