This article is a clinical and biomechanical study which documents the potential for over-stuffing of the radial capitellar joint with new and modular prosthetic radial heads. The study is a review of 6 patients who received modular radial head implants and had a clinically significant decrease in elbow flexion. Removal of the implant resulted in improved elbow flexion. The authors used fresh frozen upper extremity specimens and resected the radial head in each specimen. They monitored the radial capitellar gap and found there was significant smaller radiocapitellar gap during elbow flexion as compared with elbow extension.
The overall premise of these authors is that longitudinal over-stuffing of the radial capitellar axis can occur if the prosthesis is placed with the patient's elbow in extension. Care must be taken to avoid over-stuffing the prosthesis and to monitor the radio-capitellar gap with the elbow placed in flexion.
Journal of Shoulder & Elbow Surgery