title: The effects of glenoid wear patterns on patients with osteoarthritis in total shoulder arthroplasty: an assessment of outcomes and value.
abstract: BACKGROUND
  Despite the success of total shoulder arthroplasty (TSA), concerns remain about the longevity of the implant, in particular, glenoid component survivorship. The purpose of this study was to determine whether preoperative glenoid wear patterns affect clinical outcomes and value in patients undergoing TSA.
  
  
  METHODS
  A comparative cohort study was conducted of 309 patients with a total of 344 TSA procedures, performed for primary glenohumeral osteoarthritis. Computed tomography scans were obtained in all patients, with preoperative glenoid wear pattern characterized as either concentric (n = 196; follow-up time, 49.2 months) or eccentric (n = 148; follow-up time, 52.3 months) according to a modified Levine classification. A clinical, radiographic, and economic assessment was performed between the 2 wear patterns.
  
  
  RESULTS
  There was no significant difference in American Shoulder and Elbow Surgeons (ASES) score in the concentric group (80.8 ± 20.8) compared with the eccentric group (77.6 ± 21.2) at final follow-up (P = .159). Range of motion and final visual analog scale for pain score were similar between the 2 groups. Radiographic evidence of gross glenoid loosening was significantly lower in the concentric group [11 of 195 (5.6%)] compared with the eccentric group [18 of 147 (12.2%)] (P = .030). Revision rates were similar between the concentric group [4 of 195 (2.0%)] and the eccentric group [3 of 147 (2.0%)]. A value assessment also showed no significant difference between the concentric and eccentric groups [concentric 26.1 vs. eccentric 25.5 (ΔASES score/$10,000 hospital cost) (P = .479)].
  
  
  CONCLUSIONS
  Similar clinical results and value can be expected with both concentric and eccentric glenoid wear patterns in TSA. Concerns arise, however, as the eccentric group demonstrated a more than 2-fold increased rate of glenoid component loosening compared with the concentric group.
authors.affiliation: Shoulder and Elbow Service, Florida Orthopaedic Institute, Tampa, FL, USA.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Hussey
authors.affiliation: Shoulder and Elbow Service, Florida Orthopaedic Institute, Tampa, FL, USA.
authors.forename: Brandon M
authors.initials: BM
authors.lastname: Steen
authors.affiliation: Shoulder and Elbow Service, Florida Orthopaedic Institute, Tampa, FL, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Cusick
authors.affiliation: Phillip Spiegel Orthopaedic Research Laboratory, Foundation for Orthopaedic Research and Education, Tampa, FL, USA.
authors.forename: Jacob L
authors.initials: JL
authors.lastname: Cox
authors.affiliation: Phillip Spiegel Orthopaedic Research Laboratory, Foundation for Orthopaedic Research and Education, Tampa, FL, USA.
authors.forename: Scott T
authors.initials: ST
authors.lastname: Marberry
authors.affiliation: Phillip Spiegel Orthopaedic Research Laboratory, Foundation for Orthopaedic Research and Education, Tampa, FL, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Simon
authors.affiliation: Phillip Spiegel Orthopaedic Research Laboratory, Foundation for Orthopaedic Research and Education, Tampa, FL, USA.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Cottrell
authors.affiliation: Phillip Spiegel Orthopaedic Research Laboratory, Foundation for Orthopaedic Research and Education, Tampa, FL, USA.
authors.forename: Brandon G
authors.initials: BG
authors.lastname: Santoni
authors.affiliation: Shoulder and Elbow Service, Florida Orthopaedic Institute, Tampa, FL, USA. Electronic address: mfrankle@floridaortho.com.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Frankle
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D061165:Glenoid Cavity / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000150:complications / Q000601:surgery*; D010147:Pain Measurement; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012086:Reoperation; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000601:surgery*; D020069:Shoulder Pain / Q000209:etiology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: Total shoulder arthroplasty; concentric; eccentric; glenohumeral osteoarthritis; glenoid wear