Accessory bones of the elbow: Prevalence, localization and modified classification

Area of Science:

• Orthopedic Surgery
• Human Anatomy
• Radiology

Background:

• Accessory bones in the elbow are uncommon anatomical variations.
• These structures can be misdiagnosed as avulsion fractures, impacting patient care.
• Understanding their prevalence and characteristics is crucial for accurate diagnosis.

Purpose of the Study:

• To determine the prevalence of accessory elbow bones in a Central European population.
• To analyze the congenital origin and precise anatomical locations of these bones.
• To investigate potential correlations with age and calcar olecrani.

Main Methods:

• Radiographic evaluation of 2413 elbow X-rays (anteroposterior and lateral views).
• Identification and characterization of accessory bony structures.
• Logistic regression analysis to assess relationships with patient age and calcar olecrani.

Main Results:

• The overall prevalence of accessory elbow bones was found to be 0.77%.
• Os subepicondylare mediale (type V) was the most frequent type (0.46%), followed by os subepicondylare laterale (type III; 0.21%).
• No statistically significant relationship was observed between accessory bones, patient age, or the presence of calcar olecrani.

Conclusions:

• Congenital accessory elbow bones are a rare finding.
• Accurate knowledge of their specific locations is essential for differentiating them from fractures.
• This study contributes data on prevalence and localization to aid clinical diagnosis.