title: Revision arthroplasty with a hip-inspired computer-assisted design/computer-assisted manufacturing implant for glenoid-deficient shoulders.
abstract: BACKGROUND
  Revision arthroplasty for failed post-traumatic humeral head replacement associated with rotator cuff and glenoid deficiency is challenging. Current surgical solutions are fraught with complications, and no best-practice strategy has been established. We hypothesized that the computer-assisted design/computer-assisted manufacturing (CAD/CAM) shoulder (Stanmore Implants, Elstree, UK), a total shoulder design resembling a total hip prosthesis, can offer a reliable alternative in this surgically challenging subset of patients with rotator cuff deficiency and advanced glenoid bone loss.
  
  
  METHODS
  Twenty-one patients with failed post-traumatic humeral head replacement associated with rotator cuff and glenoid deficiency underwent revision with CAD/CAM shoulders between 2005 and 2010. Clinical data were collected prospectively and analyzed at a mean follow-up of 3 years.
  
  
  RESULTS
  After revision, the pain rating at rest (on a 0-10 numerical scale) decreased from 5.6 ± 1.3 to 1.1 ± 1.3 (P < .001) and pain during activity decreased from 7.4 ± 1.2 to 2.1 ± 1.8 (P < .001). The Oxford shoulder score improved from 47 ± 6 to 31 ± 9 (P < .001), and the subjective shoulder value (on a 0%-100% scale) improved from 22% ± 14% to 45% ± 18% (P < .001). Active shoulder range of motion was similar before and after revision. Postoperative complications occurred in 9 patients and included 1 infection, 2 periprosthetic fractures, 2 prosthetic dislocations, and 4 fixation screw fractures. No case of glenoid loosening occurred.
  
  
  CONCLUSIONS
  The CAD/CAM shoulder offers a reliable method of securing a glenoid component in shoulders with advanced glenoid deficiency and should be considered as an alternative to other surgical methods in these challenging cases. At 3 years' follow-up, pain and clinical scores improved significantly and no case of glenoid loosening occurred.
authors.affiliation: The Shoulder and Elbow Service, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK. Electronic address: ofiruri@gmail.com.
authors.forename: Ofir
authors.initials: O
authors.lastname: Uri
authors.affiliation: The Shoulder and Elbow Service, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK.
authors.forename: Verona
authors.initials: V
authors.lastname: Beckles
authors.affiliation: The Shoulder and Elbow Service, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Falworth
authors.affiliation: The Shoulder and Elbow Service, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK.
authors.forename: Deborah
authors.initials: D
authors.lastname: Higgs
authors.affiliation: The Shoulder and Elbow Service, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Lambert
mesh_terms: D000328:Adult; D000368:Aged; D019643:Arthroplasty, Replacement / Q000379:methods*; D001862:Bone Resorption / Q000150:complications / Q000601:surgery; D017076:Computer-Aided Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D058430:Humeral Head / Q000293:injuries / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011859:Radiography; D016059:Range of Motion, Articular; D012086:Reoperation; D017006:Rotator Cuff / Q000601:surgery; D000070636:Rotator Cuff Injuries; D012540:Scapula / Q000000981:diagnostic imaging / Q000601:surgery; D012784:Shoulder Fractures / Q000150:complications / Q000601:surgery*; D013708:Tendon Injuries / Q000150:complications / Q000601:surgery*
keywords: CAD/CAM; Case Series; Humeral head replacement; Level IV; Treatment Study; arthroplasty failure; custom implant; glenoid bone graft; glenoid deficiency; revision shoulder arthroplasty; shoulder hemiarthroplasty