Outcomes following fracture fixation with the Equinoxe® proximal humerus plate: an improvement over PHILOS®?

Introduction: The purpose of this study is to compare patient outcomes between the Equinoxe® (Exactech, Gainesville, Fla) proximal humerus locking plate and the PHILOS® (Synthes, Paoli, PA) proximal humerus locking plate.

Methods: Two hundred and seventy-one patients with a displaced proximal humerus fracture presented to our academic medical center between February 2003 and October 2020. Functional outcomes assessed included the Disabilities of the Arm, Shoulder, and Hand questionnaire and shoulder range of motion. Radiographs were utilized to determine fracture healing and development of posttraumatic osteoarthritis or osteonecrosis.

Results: Overall, 108 Equinoxe® and 87 PHILOS® patients treated by a single surgeon with complete clinical, functional, and radiographic follow-up were included in the study. Demographics were similar between groups. One hundred and eight Equinoxe® patients healed at a mean time to union by 3.7 ± 2.2 months, and 86 PHILOS® patients healed (p = 0.24) by 4.1 ± 2.3 months after surgery (p = 0.31). Shoulder external rotation was greater in Equinoxe® patients by 7 degrees (p = 0.044), and forward elevation was greater by 16 degrees (p = 0.005) at one-year follow-up. DASH scores were similar between patients at the 3-, 6-, and 12-month follow-up (p = 0.86, p = 0.77, p = 0.64). Fewer Equinoxe® patients experienced complications (p = 0.043).

Conclusion: Fixation of a proximal humerus fracture can safely be performed with both Equinoxe® and PHILOS® proximal humerus locking plates. Patients fixed with Equinoxe® plates achieved a slightly greater degree of external rotation, forward elevation, and experienced fewer complications. This difference may be due to surgeon experience rather than the implant itself.