Arthroscopy in Mason type 1 radial head fractures. Diagnostic and therapeutic importance

Background. Conservative treatment of Mason type I radial head fractures normally results in a satisfactory functional outcome. However cases with reduced functional outcome, which may be caused by concomitant injuries, have been reported. Fracture classification and treatment might be influenced by these concomitant injuries. Arthroscopy represents a modern option for diagnosis and treatment in radial head fractures. Materials and methods. A total of 7 patients >= 18 years (mean age 48 +/- 7.7 years) with acute Mason type I radial head fractures and suspicion of concomitant injuries were included in this retrospective, multicenter study. Arthroscopically assisted surgical treatment was performed. Results. In the patients included, fracture classification changed in 86% of conventional x-rays and 17% of computed tomography images (CT). Osborne-Coterill lesions were not recognized in 100% of x-rays and 60% of CTs. Free joint bodies were not recognized in 100% of conventional x-rays. Osteochondral lesions of the capitulum of the humerus were not recognized in 100% of x-rays and 50% of CTs. Posterolateral elbow rotatory instability (PLRI) using the posterolateral pivot-shift test was observed in 29% of cases and was treated by internal bracing. In 43% of cases, arthroscopically assisted percutaneous screw fixation was used to treat the radial head fracture. Conclusion. Concomitant injuries that are misclassified or not identified can lead to reduced functional outcome. Compared to x-ray imaging, which is associated with lower diagnostic reliability, especially in free body joints, small fragments and osteochondral lesions, CT offers better diagnostic reliability. The best reliability is provided by arthroscopy, which allows concomitant injuries and the fracture to be treated.