title: Accuracy and reliability of postoperative radiographic measurements of glenoid anatomy and relationships in patients with total shoulder arthroplasty.
abstract: BACKGROUND
  Radiographic imaging is the follow-up imaging modality most widely used for patients who have undergone total shoulder arthroplasty (TSA). However, its accuracy of measurement of component position has not been validated against a gold standard in a clinical series.
  
  
  METHODS
  Thirty-two x-ray images and computed tomography scans were taken within 1 month of each other in patients who had undergone TSA with an all-polyethylene glenoid component. The humeral glenoid alignment in the coronal superior-inferior (SI) plane (HGA-SI), humeral glenoid alignment in the axial anterior-posterior (AP) plane (HGA-AP), and humeral scapular alignment in the axial plane (HSA-AP) were measured with 21 pairs of images, and glenoid component retroversion was measured with all 32 pairs. Intraclass correlation coefficients (ICC) were calculated for HGA-SI, HGA-AP, HSA-AP, and version, and accuracy analysis criteria of the radiographs were assessed using predetermined criterion.
  
  
  RESULTS
  We found fair-moderate agreement between x-ray images and CT scans for HGA-SI (ICC = 0.42) and version (ICC = 0.69), but poor agreement for HGA-AP (ICC = 0.04) and HSA-AP (ICC = 0.38). An average difference of overestimating HGA-SI by 0.06% ± 7.7%, with a precision 95% confidence interval of 7.6%, and overestimating version by -4.2° ± 5.1°, with a precision 95% confidence interval of 9.9°, was found.
  
  
  CONCLUSIONS
  This validation study has defined the ability and limitation for these measurements using high-quality axillary and AP radiographs.
authors: Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH 44195, USA.
authors: Jason C
authors: JC
authors: Ho
authors: Ari
authors: A
authors: Youderian
authors: Iyooh U
authors: IU
authors: Davidson
authors: Jason
authors: J
authors: Bryan
authors: Joseph P
authors: JP
authors: Iannotti
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D007595:Joint Prosthesis; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging* / Q000601:surgery*; D011184:Postoperative Period; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012540:Scapula / Q000000981:diagnostic imaging*; D012785:Shoulder Joint; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: 3D computed tomography; Development of Diagnostic Criteria; Diagnostic Study; Level II; Shoulder arthroplasty; glenoid version; humeral head registration; x-ray