Prognostic value of the Neer and Mayo-Fundacion Jimenez Diaz classifications in reverse shoulder arthroplasty for proximal humerus fractures

Reverse total shoulder arthroplasty (rTSA) is the preferred surgical treatment for non-reconstructible 7 proximal humerus fractures in the elderly population. The most common classification for 8 these fractures is the Neer classification. A more recent system is the Mayo-Fundación Jiménez 9 Díaz (Mayo-FJD) classification, which has demonstrated higher intraobserver and interobserver 10 reliability compared to the Neer system. However, their predictive utility remains unclear.

The study consisted of a retrospective analysis of prospectively collected data from 40 patients treated for isolated proximal humerus fractures with rTSA by a shoulder and elbow fellowship-trained orthopedic surgeon between 2010 and 2020. Data collection included demographic information, post-operative range of motion, pain, and patient-reported outcome measures including the Simple Shoulder Test, the University of California Los Angeles score, the American Shoulder and Elbow Surgeons, and Constant Murley scores, among others. The 9 categories of the Mayo-FJD were organized into 3 groups: isolated tuberosity fractures-greater tuberosity or lesser tuberosity; humeral head compromising fractures-varus posteromedial (VPM), valgus impacted, head split (HS), head dislocation (HD), and head impression (VPM, valgus lateral, HS, HD, and head impaction); and surgical neck (SN) fractures-SN and disengaged neck (SN and DN). The t-test and the Kruskal-Wallis test were utilized to compare the outcomes for each fracture pattern between the 2 classifications.

The final cohort consisted of 13 2-part fractures (35.1%), 19 3-part fractures (51.4%), and 5 4-part fractures (13.5%) by the Neer classification, and there were 6 VPM (16.2%), 13 valgus lateral (35.1%), 3 HS (8.1%), 2 HD (5.4%), and 13 DN (35.1%) by the Mayo-FJD classification. Patients in the SN/DN group had increased pain with touching the back of their necks (P = .045) as well as decreased Simple Shoulder Test (P = .023) and University of California Los Angeles scores (P = .018) when compared to humeral head compromising fractures.

Our findings suggest that fractures about the SN, specifically the DN fractures, may be associated with higher levels of pain and poorer shoulder function following rTSA. However, future studies should include a larger cohort of patients with complete subtype representation to verify our conclusion.