Classification of rotator cuff tendinopathy using high definition ultrasound.

BACKGROUND: ultrasound is a valid cost effective tool in screening for rotator cuff pathology with high levels of accuracy in detecting full-thickness tears. To date there is no rotator cuff tendinopathy classification using ultrasound. The aims of this study are to define a valid high-definition ultrasound rotator cuff tendinopathy classification, which has discriminate validity between groups based upon anatomical principles.

METHODS: 464 women, aged 65-87, from an established general population cohort underwent bilateral shoulder ultrasound and musculoskeletal assessment. Sonographer accuracy was established in a separate study by comparing ultrasound findings to the gold standard intra-operative findings.

RESULTS: there were 510 normal tendons, 217 abnormal tendons, 77 partial tears, and 124 full-thickness tears. There was no statistical difference in age or the proportion with pain between the abnormal enthesis and partial tear groups, however both groups were statistically older (p<0.001) and had a greater proportion with pain (p<0.001 & p=0.050) than normal tendons. The full-thickness tears were statistically older than normal tendons (p<0.001), but not abnormal/partially torn tendons. The proportion with pain was significantly greater than both groups (p<0.001 & p=0.006). Symptomatic shoulders had a larger median tear size than asymptomatic shoulders (p=0.006). Using tear size as a predictor of pain likelihood, optimum sensitivity and specificity occurred when dividing tears into groups up to 2.5cm and >2.5cm, which corresponds with anatomical descriptions of the width of the supraspinatus tendon.

CONCLUSION: the classification system is as follows: Normal Tendons; Abnormal enthesis/Partial-thickness tear; Single tendon full-thickness tears (0-2.5cm); Multi-tendon full-thickness tears (>2.5cm).