title: An uncemented metal-backed glenoid component in total shoulder arthroplasty for osteoarthritis: factors affecting survival and outcome.
abstract: BACKGROUND
  The reported survivorship of total shoulder replacement (TSR) is variable. This is probably related to implant design. We report the outcome and survivorship of the uncemented glenoid in patients with osteoarthritis receiving a TSR with an intact or repairable rotator cuff at surgery.
  
  
  METHODS
  Thirty-two consecutive patients were analysed after TSR using a screw-fixed porous coated metal-back glenoid performed by a single surgeon, with a minimum follow-up of five years. Thirty-three TSRs in 32 patients (19 women) with a mean age of 67 years were analysed, two of whom died before five years of follow-up. Thirty patients (31 shoulders) were monitored for a mean of 95 months (60-173 months).
  
  
  RESULTS
  The Constant score improved by 22 points (p < 0.001). The only significant predictor of outcome on logistic regression analysis was the preoperative Constant score, with better scores resulting in a lesser improvement at last follow-up (p < 0.0001). Implant survivorship at ten years was 93 %. Three were revisions: two for polyethylene wear (both at six years) but with a well-fixed glenoid, and another for loosening of the glenoid at 11 years postoperatively. Univariate analysis identified that younger age (56 year vs. 68 years, p = 0.03) and a higher combined preoperative Constant score (35.7 vs. 21.5, p = 0.03) were both predictors of failure.
  
  
  CONCLUSIONS
  The uncemented glenoid performs well in the medium term for osteoarthritis of the shoulder in older patients, giving improved and sustained functional outcome. Age and preoperative level of function are predictors of outcome and survival.
authors.affiliation: Department of Orthopaedics and Trauma, Royal Infirmary of Edinburgh, Edinburgh EH16 4SA, UK. nickclement@doctors.org.uk
authors.forename: N D
authors.initials: ND
authors.lastname: Clement
authors.forename: A D
authors.initials: AD
authors.lastname: Duckworth
authors.forename: R C
authors.initials: RC
authors.lastname: Colling
authors.forename: A N
authors.initials: AN
authors.lastname: Stirrat
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement / Q000379:methods* / Q000401:mortality; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007595:Joint Prosthesis; D008297:Male; D010003:Osteoarthritis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D012307:Risk Factors; D012785:Shoulder Joint / Q000601:surgery*; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology