title: Revision surgery of reverse shoulder arthroplasty.
abstract: BACKGROUND
  There is limited knowledge regarding revision of reverse shoulder arthroplasty (RSA). This study assesses reasons for failure in RSA and evaluates the outcomes of revision RSA.
  
  
  METHODS
  Between 1997 and 2009, 37 patients with RSA had revision surgery. Clinical and radiologic examinations performed preoperatively and at 3 months, at 6 months, and then annually postoperatively were analyzed retrospectively. Patients were reviewed with a minimum 2-year follow-up.
  
  
  RESULTS
  The most common causes for RSA revision were prosthetic instability (48%); humeral loosening, derotation, or fracture (21%); and infection (19%). Only 2 patients (3%) had to be reoperated on for glenoid loosening. More than 1 re-intervention was performed in 11 patients (30%) because of recurrence of the same complication or appearance of a new complication. Underestimation of humeral shortening and excessive medialization were common causes of recurrent prosthetic instability. Proximal humeral bone loss was found to be a cause for humeral loosening or derotation. Previous surgery was found as a potential cause of low-grade infection. At a mean follow-up of 34 months, 32 patients (86%) had retained the RSA whereas 2 patients (6%) had undergone conversion to humeral hemiarthroplasty and 3 (8%) to a resection arthroplasty. The mean Constant score in patients who retained the RSA increased from 19 points before revision to 47 points at last follow-up (P < .001).
  
  
  CONCLUSIONS
  Even if revision may lead to several procedures in the same patient, preservation or replacement of the RSA is largely possible, allowing for a functional shoulder. Full-length scaled radiographs of both humeri are recommended to properly assess humeral shortening and excessive medialization before revision.
authors.affiliation: Department of Orthopaedic Surgery and Sports Traumatology, Hôpital de L'Archet, University of Nice Sophia-Antipolis, Nice, France. Electronic address: boileau.p@chu-nice.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Boileau
authors.forename: Barbara
authors.initials: B
authors.lastname: Melis
authors.forename: David
authors.initials: D
authors.lastname: Duperron
authors.forename: Grégory
authors.initials: G
authors.lastname: Moineau
authors.forename: Adam P
authors.initials: AP
authors.lastname: Rumian
authors.forename: Yung
authors.initials: Y
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012086:Reoperation; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: Case Series; Level IV; Reversed shoulder arthroplasty; Treatment Study; implant loosening; infection; instability; revision