Evaluating postoperative rotator cuff healing: Prospective comparison of MRI and ultrasound

Abstract Background The objective of this prospective comparative single centre study was to compare postoperative rotator cuff healing rates as assessed by magnetic resonance imaging (MRI) versus ultrasonography (US). Material and methods Between October 2012 and February 2013, 61 patients underwent arthroscopic repair of postero-superior rotator cuff tears. Each patient underwent MRI and US 6 months later. The findings were assessed independently by two observers. We compared intra-observer and inter-observer levels of agreement regarding healing rates assessed by MRI and US. Results Intra-observer agreement regarding the MRI interpretation was 95% (κ coefficient, 0.83) for one observer and 98% (κ coefficient, 0.94) for the other. Values of κ for inter-observer agreement ranged across readings from 0.76 to 0.90. When MRI was taken as the reference, US had 80% sensitivity and 98% specificity. Discussion MRI and US provide similar assessments of postoperative rotator cuff healing, although US is less sensitive. Intra-observer and inter-observer agreements are very good. Level of evidence III.