title: The Copeland resurfacing humeral head implant does not restore humeral head anatomy. A retrospective study.
abstract: OBJECTIVE
  Recently, there has been concern that the Copeland resurfacing humeral head implant (RHHI) leaves the shoulder joint overstuffed. The purpose of this study was in a selected cohort of patients operated with a Copeland RHHI (1) to evaluate the Length of the Gleno-Humeral Offset (LGHO), (2) to assess the patient-reported quality of life and functional outcome measured by Western Ontario Osteoarthritis of the Shoulder Index (WOOS) and (3) to determine the number of revisions in the cohort.
  
  
  METHODS
  Pre- and postoperative radiographs were retrieved from 71 of 91 possible patients operated with a Copeland RHHI from 2005 to 2009. The cohort consisted of 30 males and 41 females at a mean age of 61 (38-89) years. One radiologist measured the LGHO and performed double measurements. The WOOS score 1 year after surgery and the number of revisions from all patients operated with a Copeland RHHI in Denmark was requested from the Danish Shoulder Arthroplasty Registry.
  
  
  RESULTS
  The mean LGHO was 4.99 ± 0.53 cm before surgery and 5.39 ± 0.58 cm after surgery, (p < 0.001). 95 % limits of agreement for measurements of LGHO were ± 0.11 cm. One year after surgery, the WOOS score was 67 for the cohort and 64 for all patients operated with a Copeland RHHI in Denmark. 13 of 71 RHHI in the cohort were revised.
  
  
  CONCLUSIONS
  The Copeland RHHI causes significantly increased LGHO and leads to overstuffing in the shoulder joint. The WOOS score in the cohort was comparable to that for all other Danish patients operated with a Copeland RHHI.
authors.affiliation: Department of Orthopaedics, Aarhus University Hospital, Tage-Hansens Gade 2, Aarhus C, Denmark. inger.mechlenburg@ki.au.dk
authors.forename: Inger
authors.initials: I
authors.lastname: Mechlenburg
authors.forename: Anders
authors.initials: A
authors.lastname: Amstrup
authors.forename: Thomas
authors.initials: T
authors.lastname: Klebe
authors.forename: Stig Storgaard
authors.initials: SS
authors.lastname: Jacobsen
authors.forename: Gerhardt
authors.initials: G
authors.lastname: Teichert
authors.forename: Maiken
authors.initials: M
authors.lastname: Stilling
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement; D005260:Female; D006801:Humans; D058430:Humeral Head / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000601:surgery*; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011788:Quality of Life; D011859:Radiography; D020127:Recovery of Function; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000601:surgery*