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International audience; IntroductionRotator cuff fatty infiltration (FI) is one of the most important parameters to predict the outcome of certain shoulder conditions. The primary objective of this study was to define a new computed tomography (CT)-based quantitative 3-dimensional (3D) measure of muscle loss (3DML) based on the rationale of the 2-dimensional (2D) qualitative Goutallier score. The secondary objective of this study was to compare this new measurement method to traditional 2D qualitative assessment of FI according to Goutallier et al and to a 3D quantitative measurement of fatty infiltration (3DFI).Materials and Methods102 CT scans from healthy shoulders (46) and shoulders with cuff tear arthropathy (21), irreparable rotator cuff tears (18), and primary osteoarthritis (17) were analyzed by three experienced shoulder surgeons for subjective grading of fatty infiltration according to Goutallier and their rotator cuff muscles were manually segmented. Quantitative 3D measurements of fatty infiltration (3DFI) were completed. The volume of muscle fibers without intra-muscular fat was then calculated for each rotator cuff muscle and normalized to the patient’s scapular volume to account for the effect of body size (NVfibers). Three-dimensional muscle mass (3DMM) was calculated by dividing the NVfibers value of a given muscle by the mean expected volume in healthy shoulders. Three-dimensional muscle loss (3DML) was defined as 1-(3DMM). The correlation between Goutallier grading, 3DFI, and 3DML was compared using a Spearman Rank correlation.ResultsInterobserver reliability for the traditional 2D Goutallier grading was moderate for the infraspinatus (ISP=0.42) and fair for the supraspinatus (SSP=0.38), subscapularis (SSC=0.27) and teres minor (TM=0.27). 2D Goutallier grading was found to be significantly and highly correlated with 3DFI (SSP=0.79, ISP=0.83, SSC=0.69, TM=0.45) and 3DML (SSP=0.87, ISP=0.85, SSC=0.69, TM=0.46) for all four rotator cuff muscles (p

The purpose of this study was to analyze the in vivo dimensions of each tibial plateau for planning of unicompartmental knee arthroplasty (UKA), and to compare the morphometric data to the dimensions of nine current designs of UKA tibial components. Thirty-seven knees (31 females and 6 males) operated on with UKA were studied. All patients were examined postoperatively using computed tomography (CT). There were 18 lateral and 19 medial UKAs. On the CT scan, each operated tibial plateau was measured in the transverse plane at the resection level, just below the full polyethylene tibial component. We measured the length of the anteroposterior (AP) cut as well as the maximal mediolateral dimension of the resected plateau (perpendicular to the AP cut). We compared the measurements with nine current UKA systems: Accuris (Smith and Nephew), Advance (Wright Medical), HLS Uni Evolution (Tornier), Miller-Galante and 'ZUK' (Zimmer), Oxford and Oxford a (Biomet), Preservation (DePuy) and Unix (Stryker). There was good correlation between patient height and mediolateral dimension (r = 0.6), and between patient height and area of total tibial plateau (r = 0.7). The anteroposterior dimension was greater for the medial plateau (mean 50.8 mm, SD 3.3) than for the lateral plateau (mean 47.2 mm, SD 3.3). This difference was statistically significant (P = 0.0016). Some UKA implants are designed with an asymmetric femoral component, but none have an asymmetric tibial component. The present study suggests, however, that the shape of the medial tibial plateau differs from that of the lateral plateau. This difference can lead to mediolateral overhang for medial UKA, if the surgeon aims for optimal anteroposterior coverage.