title: Elucidating trends in revision reverse total shoulder arthroplasty procedures: a retrieval study evaluating clinical, radiographic, and functional outcomes data.
abstract: BACKGROUND
  The purpose of this study was to explore relationships between damage modes in explanted reverse total shoulder arthroplasty (RTSA) components, patient and radiographic risk factors, and functional data to elucidate trends in RTSA failure.
  
  
  METHODS
  Fifty RTSA systems, retrieved from 44 patients, with 50 polyethylene (PE) liners, 30 glenospheres, 21 glenoid baseplates, 13 modular humeral metaphases, and 17 humeral stems, were examined for damage modes, including abrasion, burnishing, dishing, embedding, scratching, and pitting. PE liners were also analyzed for delamination and edge deformation. Charts were reviewed for patient, surgical, and functional data. Pre-revision radiographs were analyzed for scapular notching and loosening.
  
  
  RESULTS
  Average term of implantation was 20 months (range, 0-81 months). Metallic components exhibited abrasion, burnishing, dishing, pitting, and scratching. PE liners displayed all damage modes. Damage was exhibited on 93% of glenospheres and 100% of PE liners. Of 29 aseptic shoulders, 13 showed evidence of scapular notching and 5 of humeral loosening. There was a moderate correlation between radiographically observed implant failure or dissociation and PE embedding (r = 0.496; P < .001). There were weak and moderate correlations between scapular notching severity and PE dishing (r = 0.496; P = .006), embedding (r = 0.468; P = .010), and delamination (r = 0.384; P = .040).
  
  
  CONCLUSIONS
  To date, this is the largest series of retrieved RTSA components and the first to relate damage modes to radiographic and clinical data. Most damage was observed on the PE liners, on both the articular surface and rim, and glenosphere components. Correlation of retrieval findings with radiographic and clinical data may help establish predictors of prostheses at risk for failure.
authors.affiliation: Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, MI, USA.
authors.forename: Brett P
authors.initials: BP
authors.lastname: Wiater
authors.affiliation: Department of Orthopaedic Research, Beaumont Health System, Royal Oak, MI, USA; Department of Surgery, Oakland University William Beaumont School of Medicine, Rochester, MI, USA.
authors.forename: Erin A
authors.initials: EA
authors.lastname: Baker
authors.affiliation: Department of Orthopaedic Research, Beaumont Health System, Royal Oak, MI, USA.
authors.forename: Meagan R
authors.initials: MR
authors.lastname: Salisbury
authors.affiliation: Department of Orthopaedic Research, Beaumont Health System, Royal Oak, MI, USA.
authors.forename: Denise M
authors.initials: DM
authors.lastname: Koueiter
authors.affiliation: Department of Orthopaedic Research, Beaumont Health System, Royal Oak, MI, USA; Department of Surgery, Oakland University William Beaumont School of Medicine, Rochester, MI, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Baker
authors.affiliation: Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, MI, USA.
authors.forename: Betsy M
authors.initials: BM
authors.lastname: Nolan
authors.affiliation: Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, MI, USA; Department of Surgery, Oakland University William Beaumont School of Medicine, Rochester, MI, USA. Electronic address: mwiater@beaumont.edu.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Wiater
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012086:Reoperation / Q000639:trends; D012307:Risk Factors; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery
keywords: Reverse total shoulder arthroplasty; implant damage; implant retrieval; scapular notching