ANATOMICALLY CONTOURED STEM RADIAL HEAD PROSTHESIS: A PROSPECTIVE CASE SERIES IN YOUNG ADULTS WITH UNRECONSTRUCTIBLE MASON TYPE III RADIAL HEAD FRACTURES

Abstract

Background: Radial head arthroplasty (RHA) is commonly used when a Mason type III radial head fracture cannot be reliably reconstructed. Contemporary evidence indicates clinically important differences among implant designs and fixation strategies, but the specific technical behavior of anatomically contoured stems in young adults remains insufficiently characterized. [1,4-9] Objective: To evaluate stem-specific intraoperative findings and early radiological and functional outcomes after primary RHA using an anatomically contoured, pre-bent stem in young adults with unreconstructible Mason type III radial head fractures. Methods: In this prospective observational case series, 15 consecutive patients aged 21-44 years underwent primary RHA and were followed for 12 months. Prospectively recorded variables included insertion characteristics, cortical impingement, additional canal preparation, initial press-fit stability, sizing mismatch, stem alignment, Mayo Elbow Performance Score (MEPS), visual analogue scale (VAS) pain, elbow and forearm range of motion, radiocapitellar congruity, radiographic findings, and complications. Outcomes were summarized descriptively. Results: Mean age was 31.9 ± 6.8 years; 10 patients (66.7%) were male and the dominant limb was involved in 9 (60.0%). Smooth stem insertion occurred in 11 patients (73.3%), and adequate initial press-fit fixation in 14 (93.3%). No intraoperative radial neck fracture or clinically relevant varus/valgus stem malalignment occurred. Mean MEPS increased from 58.7 ± 8.6 at 6 weeks to 92.7 ± 5.1 at 12 months; 14 patients (93.3%) had good or excellent final MEPS. Mean VAS pain decreased from 6.9 ± 1.1 preoperatively to 1.2 ± 0.8 at 12 months. At final follow-up, radiocapitellar congruity and acceptable stem alignment were maintained in all patients; no radiographic overstuffing, progressive loosening, implant migration, or revision was observed. Heterotopic ossification occurred in 2 patients (13.3%) and postoperative stiffness in 1 (6.7%). Conclusion: In this small single-centre series, an anatomically contoured, pre-bent radial head prosthesis was associated with favorable early technical, functional, and radiological outcomes. The study supports the feasibility of the evaluated design. Larger comparative studies with standardized radiographic measurements and longer follow-up are required.