Classification and measurement of displacement of isolated greater tuberosity fractures: Intra and interobserver reliability

Background Literature demonstrates variability in the amount of displacement of isolated greater tuberosity (GT) fractures and measurement techniques that orthopaedic surgeons deem warrant surgical intervention. This study aims to assess the intra and interobserver reliability for classifying and measuring the displacement amount for isolated GT fractures. Methods Eight surgeons, consisting of four shoulder specialists and four trainee surgeons, reviewed 25 plain radiographs on two separate occasions, 3 months apart. They were required to morphologically classify the GT fracture, measure the displacement distance on anteroposterior and axillary views, calculate the GT displacement ratio, and state whether they would offer surgical treatment. Results There was a lack of good reliability for the classification of the depression and avulsion fracture types. There was good intraobserver but poor interobserver consistency in classifying the split-type fractures. The measurement of the displacement distance showed good intraobserver reliability, but not as good interobserver agreement. Also, the displacement ratio calculated revealed poor consistency. We found good agreement between and within the raters for the treatment decision. No significant difference was noted when comparing the senior surgeons to the junior surgeons. Conclusions This study has revealed ongoing inconsistency in the classification and measurement of isolated GT fractures.