Loose Fit Monobloc Versus Cemented Bipolar Radial Head Prosthesis in the Treatment of Radial Head Fractures: A...

Background: Radial head arthroplasty is commonly used for unreconstructable radial head fractures, particularly in cases associated with elbow instability. Both loose-fit monobloc and cemented bipolar radial head prostheses are available, but comparative evidence regarding their clinical and radiographic outcomes remains limited. This study aimed to compare mid-term outcomes between these two implant designs. Methods: A retrospective observational study was conducted on 26 patients who underwent radial head arthroplasty for acute radial head fractures between November 2020 and October 2023. Fourteen patients received a loose-fit monobloc radial head prosthesis, while twelve received a cemented bipolar prosthesis. Clinical, functional, and radiographic outcomes were assessed at a minimum follow-up of 24 months. Outcome measures included range of motion, pain, elbow stability, satisfaction, ADL (activities of daily living), IADL (instrumental activities of daily living), SF-12 (12-Item Short Form Health Survey), Oxford Elbow Score, Mayo Elbow Performance Score, DASH (disability of the arm, shoulder and hand score) score, implant loosening, heterotopic ossification, and complications. Results: No statistically significant differences were observed between the two groups in pain, satisfaction, range of motion, elbow stability, functional scores, radiographic loosening, or complication rates. The cemented bipolar group showed slightly better flexion-extension and pronation-supination values, whereas the loose-fit group showed a numerically lower rate of elbow instability; however, these differences were not statistically significant. No cases of aseptic loosening, periprosthetic osteolysis, or undesired implant loosening were observed. The complication rate was 36% in the loose-fit group and 33% in the cemented group. One patient in the loose-fit group required revision surgery due to implant overstuffing. Conclusions: Both loose-fit monobloc and cemented bipolar radial head prostheses provided acceptable mid-term functional scores; however, the relatively high overall complication rate (33-36%) highlights the need for careful implant selection, particularly with loose-fit implants, to avoid overstuffing and postoperative stiffness. Given the small cohort, these findings do not imply therapeutic equivalence.