Thomas Suter1, Nicola Krähenbühl2, C Kalebb Howell3, Yue Zhang4, Heath B Henninger5. 1. Department of Orthopaedic Surgery, Kantonsspital Baselland, Liestal, Switzerland; Department of Orthopaedics, Harold K. Dunn Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA. 2. Department of Orthopaedics, Harold K. Dunn Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA. 3. Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA. 4. Division of Epidemiology, Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA. 5. Department of Orthopaedics, Harold K. Dunn Orthopaedic Research Laboratory, University of Utah, Salt Lake City, UT, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA. Electronic address: heath.henninger@utah.edu.
Abstract
BACKGROUND: Accurate and reliable assessment of acromial tilt (ATA) and slope (ASA) angles have been important in the clinical evaluation of degenerative and traumatic rotator cuff tears. This study analyzed the influence of radiographic viewing perspective on the ATA and ASA and developed criteria to identify true lateral (TL) view radiographs. METHODS: Three-dimensional computed tomographic (CT) reconstructions of 52 scapulae without rotator cuff tears or osteoarthritis were studied. Digitally reconstructed radiographs (DRRs) were aligned to obtain a TL view. In 10 random scapulae, incremental ante- and retroversion and up- and downward rotation views were generated (10° increments, ±30°), and ATA and ASA were measured by 2 observers. Clinically applicable criteria were developed and validated to identify TL views. RESULTS: The mean ATA and ASA on TL views were 33°±4° (range 23°-42°) and 22°±7° (8°-43°), respectively. Mixed effect models showed that DRRs malpositioned in 20° and 30° anteversion and downward rotation decreased the ATA (P ≤ .030). DRRs malpositioned in anteversion and >10° of up- and downward rotation demonstrated a significantly decreased ASA (P ≤ .047). Intra- and interobserver reliability was excellent for TL views (intraclass correlation coefficient ≥ 0.95) but decreased with increasing viewing angle. Anatomic landmark criteria were capable of identifying TL-view radiographs with sensitivity of 81% and specificity of 82%. CONCLUSION: Both ATA and ASA were significantly affected by malposition in anteversion and downward rotation of the scapula. Reliable ASA measurement was more susceptible in up- and downward rotation than the ATA. New visual criteria can identify TL-view radiographs and should be used in future studies to ensure consistency in ATA and ASA measurement.
BACKGROUND: Accurate and reliable assessment of acromial tilt (ATA) and slope (ASA) angles have been important in the clinical evaluation of degenerative and traumatic rotator cuff tears. This study analyzed the influence of radiographic viewing perspective on the ATA and ASA and developed criteria to identify true lateral (TL) view radiographs. METHODS: Three-dimensional computed tomographic (CT) reconstructions of 52 scapulae without rotator cuff tears or osteoarthritis were studied. Digitally reconstructed radiographs (DRRs) were aligned to obtain a TL view. In 10 random scapulae, incremental ante- and retroversion and up- and downward rotation views were generated (10° increments, ±30°), and ATA and ASA were measured by 2 observers. Clinically applicable criteria were developed and validated to identify TL views. RESULTS: The mean ATA and ASA on TL views were 33°±4° (range 23°-42°) and 22°±7° (8°-43°), respectively. Mixed effect models showed that DRRs malpositioned in 20° and 30° anteversion and downward rotation decreased the ATA (P ≤ .030). DRRs malpositioned in anteversion and >10° of up- and downward rotation demonstrated a significantly decreased ASA (P ≤ .047). Intra- and interobserver reliability was excellent for TL views (intraclass correlation coefficient ≥ 0.95) but decreased with increasing viewing angle. Anatomic landmark criteria were capable of identifying TL-view radiographs with sensitivity of 81% and specificity of 82%. CONCLUSION: Both ATA and ASA were significantly affected by malposition in anteversion and downward rotation of the scapula. Reliable ASA measurement was more susceptible in up- and downward rotation than the ATA. New visual criteria can identify TL-view radiographs and should be used in future studies to ensure consistency in ATA and ASA measurement.
Authors: Chris D Bryce; Andrew C Davison; Gregory S Lewis; Li Wang; Donald J Flemming; April D Armstrong Journal: J Bone Joint Surg Am Date: 2010-03 Impact factor: 5.284
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Authors: Teemu V Karjalainen; Nitin B Jain; Cristina M Page; Tuomas A Lähdeoja; Renea V Johnston; Paul Salamh; Lauri Kavaja; Clare L Ardern; Arnav Agarwal; Per O Vandvik; Rachelle Buchbinder Journal: Cochrane Database Syst Rev Date: 2019-01-17