Abstract: Objective To explore an approach to distinguish avulsion fracture of articular portion fromanatomic separated epiphysis. Methods 21 cases with suspicioned avulsion fracture of articular portion oftubular bone were reviewed. The cortical continuity of separate small bone and contiguous bone portionwas investigated. The swell of soft tissue around these small bones was observed simultaneously. Then theconfiguration of the fracture was researched by injury mechanics. Results Continued bone cortex betweenseparate small bone and corresponding bone was seen in 15 cases, so they were considered as a separateepiphysis. Sharp linear fracture between the separate small bone and corresponding bone were seen in 6cases. The swell of soft tissue around the separate small bone was observed in all cases, so they wereconsidered as a avulsion fracture. Conclusion The meticulous investigation of separated small bone at thearticular portion by image observation is of important value for distinguishing avulsion fracture fromanatomic separate epiphysis.

Key words: epiphysis, fracture, legal medicine