Background Isolated greater tuberosity fractures are uncommon and account for approximately 2-19% [Emerg Radiol. 2018;25(3):235-246] of all proximal humerus fractures. Surgical treatment is the prevailing recommendation in cases of displacement of more than 5 mm for the general healthy population, while conservative treatment is considered to result in inferior outcomes and is not recommended. However, high-grade evidence is lacking for these recommendations. Methods Twenty patients with conservatively treated isolated greater tuberosity fracture were evaluated prospectively as part of a registry study. Morphological Mutch classification, displacement in millimeters, and direction of displacement were determined by computed tomography (CT). Degree of fragment displacement was classified (nondisplaced to minor: <= 5 mm; moderate: 6-10 mm; major: > 10 mm). Constant score (CS), age- and sex-adjusted Constant score (adj. CS), subjective shoulder value (SSV), and radiographic follow-up were compared at a minimum follow-up of 12 months. For statistical analysis, quantitative data were compared using Mann-WhitneyUt-test. Statistical significance was set atp <= 0.05. Results Ninteen patients reached the minimum follow-up at an average of 19 months (range, 12-35 months). 13 patients were women. Average age at the time of injury was 51 years (range, 22-75 years). CS and adj. CS averaged 79 +/- 17.5 points, and 91 +/- 17.7 points, respectively. The SSV averaged 87 +/- 17%. No statistically significant difference in clinical outcomes could be observed with respect to the degree of displacement among the three groups. Conclusion The outcomes of conservatively treated displaced isolated greater tuberosity fractures are underestimated, and current indications for surgical treatment should be questioned. Further studies with larger numbers of patients and longer lengths of follow-up are needed. The protocol of this observational study is registered at ClinicalTrials.gov (NCT03060876). Date of registration: June 8, 2016.
