Hawkins Award 2025: clinical implications of radiological findings associated with radial head replacement. A long-term follow-up study

Background Radial head replacement (RHR) is indicated in comminuted fractures and those associated with elbow instability. Despite satisfactory clinical outcomes, some patients present with concerning radiographic findings. Our aim was to compare the long-term radiological results of 2 RHR designs and to correlate them with clinical findings. Methods A prospective observational cohort study including 134 patients who received an RHR (84 spacer designs and 50 anatomic models) for acute elbow instability was conducted. Patients were prospectively followed for a mean of 88 months (range, 24-204). Radiological analysis included technical implantation errors (poor position and inappropriate choice of implant size), radiolucent lines, stress shielding, heterotopic ossifications or degenerative changes. These findings were correlated to clinical outcomes according to the Mayo Elbow Performance Score; Oxford Elbow Score; and the Disabilities of the Arm, Shoulder, and Hand score. Results Radiographically, technical errors, including overstuffing, malrotation, and inadequate cortical contact, were more prevalent in the anatomic group (17 anatomic RHR cases vs. 7 patients in the spacer group, P < .001). These findings were related to greater pain ( P = .04) and a worse Disabilities of the Arm, Shoulder, and Hand score ( P = .03). Radiolucent lines were present in 58 spacer RHR (69%), being complete in 31, with only half of them being progressive. Twelve anatomic RHR (24%) showed radiolucencies, being complete and progressive in all of them. Stress-shielding was found in 22 anatomic RHR (44%), with no relation to clinical outcomes. Twelve spacer RHR and 5 anatomic implants showed heterotopic bone around the radial neck that was associated with rotational stiffness ( P < .001). Implant oversizing and loosening were the most common causes leading to implant removal of the anatomic design, with significant differences with respect to the spacer (8 vs. 4, P = .02). Conclusion Anatomic RHR has a risk of radiographic technical mistakes that correlate to poorer outcomes. Compared to the spacer, they also have a higher rate of radiographic changes leading to revision surgery, due to overstuffing and loosening.