A new classification for combined greater tuberosity fracture and anterior shoulder dislocation: A study of fracture configurations and displacement after reduction.

Objective: The aim of this study was to propose a new classification of combined greater tuberosity (GT) fractures and anterior shoulder dislocation and studied the degree of displacement, functional outcomes, and need for additional surgery after reduction.

Methods: A cross-sectional study was conducted. We evaluated radiographs of patients treated for combined GT fractures and anterior shoulder dislocation. Three morphologies were proposed; type 1 (a small avulsion), type 2 (GT fractures without articular head involvement), and type 3 (GT associated with articular head fractures). Two orthopedic surgeons independently measured all radiographs and classified fractures into three types. Patients were interviewed by telephone to assess functional outcomes (the simple shoulder test (SST) and EQ-5D-5L), and additional shoulder surgery was also performed.

Results: There were 52 eligible patients; 32 were male (61.5%) and the mean age was 57.3 · 17.1 years. Most cases were low-energy injuries (61.5%). Of all the cases, 32.7% were type I, 59.6% type II, and 7.7% type III cases. There were differences in the degree of displacement in each group at pre, post-reduction (both horizontal and vertical planes) and at two weeks post-reduction for HD (p < 0.05). Type III had more displacement than type I at pre- and post-reduction with a P value of less than 0.05. Type III also had higher rates of displacement than type II at post-reduction and at two-week postreduction (vertical plane). The intra and inter-rater reliabilities of measurement (ICC > 0.8) were in good to excellent agreement with the kappa value (>0.9). Three out of 52 cases (5.8%) required an additional surgery after closed reduction. Patients had good functional outcomes (SST score of 8) with an excellent utility index of EQ-5D-5L (0.9).

Conclusion: This new classification exhibited good-to-excellent intra-and inter-rater reliabilities, with an ability to determine injury type. Type III seems to be linked to higher risk of fracture displacement and may require additional surgery.

Level of evidence: Level IV, Diagnostic Study.