title: Linked shoulder replacement: current design problems and a new design proposal.
abstract: BACKGROUND
  Totally constrained shoulder replacement with linked components is one of the surgical options in post-tumor resection shoulder reconstruction or in complex shoulder revision operations. In this paper, we intend to shed light on such an implant design, which provides a linked constrained connection between the humeral head and the glenoid, and to show some immediate postoperative complications, implant progression to decrease the chances of implant mechanical postinsertion failure, and a new design proposal.
  
  
  METHODS
  In our center, we use the linked prosthesis in complex revision situations; however, there have been some complications, which could be attributed mainly to the engineering and the implant design, and hence potentially avoidable by making a different design to cover for those mechanical issues. Two such complications are described in this paper.
  
  
  RESULTS
  Early revisions after linked shoulder replacement implantation were needed in two occasions due to implant disconnection: one of them was due to dislodgement from the native glenoid, and the second one was due to the disengagement of the ringlet which secures the linkage mechanism between the humeral head and the implanted glenoid shell.
  
  
  CONCLUSIONS
  There is a need for a more stable design construct to avoid the reported complications that needed early revision surgeries. The new design proposed is an attempt to help providing a better and more stable implant to decrease the chances of revision in those complex situations where the patient already had many major operations, and working to increase the durability of the implant is crucial.
authors.affiliation: Royal Liverpool University, Liverpool, L69 3GA, UK. ali5214954@yahoo.com.
authors.forename: Ali Abdullah
authors.initials: AA
authors.lastname: Mohammed
authors.affiliation: Royal Liverpool University, Liverpool, L69 3GA, UK.
authors.forename: Simon Peter
authors.initials: SP
authors.lastname: Frostick
mesh_terms: D019643:Arthroplasty, Replacement; D006801:Humans; D011183:Postoperative Complications / Q000601:surgery; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012782:Shoulder / Q000601:surgery*; D012785:Shoulder Joint / Q000601:surgery*
keywords: Constrained shoulder arthroplasty; Linked shoulder; Revision shoulder replacement; Upper limb reconstruction