Comparison of CFR-PEEK and conventional titanium locking plates for proximal humeral fractures: a retrospective controlled study of patient outcomes.

BACKGROUND: Metal plates are the fixation devices used most frequently to proximal humeral fractures (PHFs). However, in recent years carbon fiber-reinforced polyetheretherketone (CFR-PEEK) plates have become increasingly common. This study compares the clinical and radiographic outcomes of 42 Neer three- and four-part PHFs treated with CFR-PEEK or metal (titanium) plates. MATERIALS AND METHODS: Forty-two PHF patients were managed with CFR-PEEK plates (n = 21, males/females 9/12; mean age 57.4 years; mean follow-up 30.7 months; CFR-PEEK group) or metal plates (n = 21; males/females 7/14; mean age 55.8 years; mean follow-up 52.7 months; Metal group). Active shoulder mobility (anterior elevation, lateral elevation, external rotation, and internal rotation), the Constant-Murley Score, the Simple Shoulder Test Score, and the pain score were recorded. Preoperative computed tomography scans and X-rays were obtained. Postoperative fracture healing and displacement, tuberosity resorption and/or malposition, hardware position, and cortical thinning (CT) under the plate were assessed radiographically. RESULTS: Shoulder mobility, clinical, and pain scores were similar in both patient groups. CT was significantly greater in CFR-PEEK patients (mean difference, 1.14 mm; p = 0.0003). In both groups, incomplete or poor calcar reduction was associated to a significantly higher complication rate, especially stiffness and muscle weakness (p = 0.016). The rate of tuberosity resorption was significantly higher in the Metal group (p = 0.040). Two patients required revision to a hemiarthroplasty (CFR-PEEK) and reverse arthroplasty (Metal group). CONCLUSIONS: CFR-PEEK plates provide a viable alternative to conventional titanium plates in PHFs, ensuring similar clinical outcomes and a lower rate of tuberosity resorption, but they involve higher stress shielding under the plate.