OBJECTIVES: Reliable assessment of fatty degeneration of rotator cuff muscles is desirable to predict the outcome of shoulder surgery. Currently used qualitative assessments are limited by relatively high inter- and intraobserver variability. It was hypothesized that a quantitative measurement of muscle density using computed tomography (CT) was more reliable and reproducible. MATERIALS AND METHODS: Thirty shoulders from patients with rheumatoid arthritis were analyzed using parasagittal multiplanar reconstructions acquired from a 16-slice CT scanner. Three observers visually rated the severity of fatty degeneration and independently outlined the rotator cuff muscles, after which the mean density was calculated. Inter- and intraobserver agreement on both measurements was expressed by the interclass correlation coefficient (ICC) and the standard deviation of the differences (SDD) between the measurements. RESULTS: A strong correlation was found between the quantitative measure and the visual rating (R2 = 0.94; P < 0.0001). The SDD in muscle density did not exceed 2.3 Hounsfield units, and the mean rotator cuff ICC (0.98) was substantially greater than that of the visual rating (0.63). CONCLUSIONS: This study describes a reproducible method to quantify fatty degeneration of the rotator cuff muscles in CT images, with a higher interobserver agreement than the visual score, and may prove a reliable tool to evaluate the quality of the rotator cuff muscles.
OBJECTIVES: Reliable assessment of fatty degeneration of rotator cuff muscles is desirable to predict the outcome of shoulder surgery. Currently used qualitative assessments are limited by relatively high inter- and intraobserver variability. It was hypothesized that a quantitative measurement of muscle density using computed tomography (CT) was more reliable and reproducible. MATERIALS AND METHODS: Thirty shoulders from patients with rheumatoid arthritis were analyzed using parasagittal multiplanar reconstructions acquired from a 16-slice CT scanner. Three observers visually rated the severity of fatty degeneration and independently outlined the rotator cuff muscles, after which the mean density was calculated. Inter- and intraobserver agreement on both measurements was expressed by the interclass correlation coefficient (ICC) and the standard deviation of the differences (SDD) between the measurements. RESULTS: A strong correlation was found between the quantitative measure and the visual rating (R2 = 0.94; P < 0.0001). The SDD in muscle density did not exceed 2.3 Hounsfield units, and the mean rotator cuff ICC (0.98) was substantially greater than that of the visual rating (0.63). CONCLUSIONS: This study describes a reproducible method to quantify fatty degeneration of the rotator cuff muscles in CT images, with a higher interobserver agreement than the visual score, and may prove a reliable tool to evaluate the quality of the rotator cuff muscles.
Authors: Johannes F Plate; Christopher M Bates; Sandeep Mannava; Thomas L Smith; Matthew J Jorgensen; Thomas C Register; John R Stehle; Kevin P High; Carol A Shively; Jay R Kaplan; Katherine R Saul; Christopher J Tuohy Journal: J Shoulder Elbow Surg Date: 2013-01-24 Impact factor: 3.019
Authors: S Hogendoorn; B J Duijnisveld; S G van Duinen; B C Stoel; J G van Dijk; W E Fibbe; R G H H Nelissen Journal: Bone Joint Res Date: 2014-02-24 Impact factor: 5.853
Authors: Jan F Henseler; Yotam Raz; Jochem Nagels; Erik W van Zwet; Vered Raz; Rob G H H Nelissen Journal: PLoS One Date: 2015-02-24 Impact factor: 3.240