title: Reverse shoulder arthroplasty: The Singapore General Hospital experience and a simple method of measuring change in the center-of-rotation.
abstract: BACKGROUND
  This study reviews the outcomes of reverse shoulder arthroplasty (RSA) and introduces a novel method of measuring changes in the center-of-rotation (COR) of the shoulder joint post-operatively.
  
  
  METHODS
  We performed 10 reverse shoulders in 2011. Patients were evaluated pre-operatively and post-operatively using the Constant Score. The COR of the shoulder was determined pre- and post-operatively on radiographs and the differences were analysed.
  
  
  RESULTS
  There was significant improvement in Constant Scores post-operatively with reduction in pain and increase in strength. Medialisation but not distalisation of the COR was achieved.
  
  
  CONCLUSIONS
  Longer follow-up studies and studies on survivalship are required.
authors.affiliation: Singapore General Hospital, Singapore.
authors.forename: Chay-You
authors.initials: CY
authors.lastname: Ang
authors.affiliation: Singapore General Hospital, Singapore.
authors.forename: Kah-Weng
authors.initials: KW
authors.lastname: Lai
authors.affiliation: Singapore General Hospital, Singapore.
authors.forename: Denny Lie
authors.initials: DL
authors.lastname: Tjiauw Tjoen
authors.affiliation: Singapore General Hospital, Singapore.
authors.forename: Paul
authors.initials: P
authors.lastname: Chang Chee Cheng
keywords: Arthroplasty; Cuff arthropathy; Reverse shoulder