The Incidence of Accessory Ossicles of the Wrist: A Radiographic Study

Objective  Accessory ossicles of the wrist are generally asymptomatic and detected incidentally as radiological findings. These bones are rarely symptomatic but can produce pain in cases of impingement or direct trauma. More frequently, these bones are misinterpreted as avulsion fractures in trauma patients, which may lead to unnecessary immobilization and overtreatment. The aim of this study is to determine the incidence of accessory ossicles of the wrist and also determine if the incidence is related to age, gender, or ongoing wrist pain. Materials and Methods  A total of 1146 wrist radiographs were included in the study. All radiographs were analyzed for the presence of 20 different accessory ossicles of the wrist. Patients were also divided into two groups, as with and without accessory ossicle. Two groups were compared in terms of age, gender, and side. Results  About 113 accessory ossicles were detected in 111 (9.7%) radiographs. The most common accessory ossicles were os triangulare and os ulnostyloideum, and the least common accessory ossicles were os gruberi and os praetrapezium. Patients who had accessory ossicle had a significantly higher age than those who did not have accessory ossicle. There was no significant difference between the patients with and without accessory ossicle in terms of gender and side. Conclusions  The results of this study showed that the most common accessory ossicles in the wrist were os triangulare and os ulnostyloideum, and the incidence of accessory bones increased with age. Clinical Relevance  Since accessory ossicles of the wrist can be confused with fractures in trauma patients and are frequently ignored in patients presenting with pain, it is very important to know the incidence and distribution of these ossicles. Therefore, this study is important, in that it provides potentially guiding anatomical data for clinicians in terms of diagnosis and management.