OBJECTIVE: To explore an approach to distinguish avulsion fracture of articular portion from anatomic separated epiphysis. METHODS: 21 cases with suspicioned avulsion fracture of articular portion of tubular bone were reviewed. The cortical continuity of separate small bone and contiguous bone portion was investigated. The swell of soft tissue around these small bones was observed simultaneously. Then the configuration of the fracture was researched by injury mechanics. RESULTS: Continued bone cortex between separate small bone and corresponding bone was seen in 15 cases, so they were considered as a separate epiphysis. Sharp linear fracture between the separate small bone and corresponding bone were seen in 6 cases. The swell of soft tissue around the separate small bone was observed in all cases, so they were considered as a avulsion fracture. CONCLUSION The meticulous investigation of separated small bone at the articular portion by image observation is of important value for distinguishing avulsion fracture from anatomic separate epiphysis.
Adolescent ; Adult ; Aged ; Ankle Injuries/diagnostic imaging* ; Epiphyses/diagnostic imaging* ; Epiphyses, Slipped/diagnostic imaging* ; Female ; Forensic Medicine ; Fractures, Bone/diagnostic imaging* ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Retrospective Studies ; Tomography, X-Ray Computed ; Young Adult

OBJECTIVE: To investigate a method to distinguish avulsion fracture from sesamoid, accessory bone, and permanent osteoepiphyte. METHODS: Fourteen cases of suspicious avulsion fractures of articular portion of tubular bones were reviewed. Direct/indirect signs and the injury mechanism of avulsion fractures were analyzed and compared with permanent osteoepiphyte, sesamoid and accessory bones for their morphological characteristics. RESULTS: There are two cases of permanent osteoepiphytes, three cases of sesamoids, and three cases of accessory bones. These cases were characterized by smooth edges, contiguous bony cortex, without swelling of the surrounding soft tissue or obvious image changes after consecutive radiography. CONCLUSION It is fundamental in image analysis to distinguish avulsion fracture from physiological small osteoepiphyte, sesamoid bone, and aberrant accessory bone.
Adolescent ; Adult ; Ankle Injuries/diagnostic imaging* ; Child ; Diagnosis, Differential ; Epiphyses/diagnostic imaging* ; Epiphyses, Slipped/diagnostic imaging* ; Female ; Forensic Medicine ; Fractures, Bone/diagnostic imaging* ; Humans ; Knee Injuries/diagnostic imaging* ; Male ; Middle Aged ; Retrospective Studies ; Sesamoid Bones/diagnostic imaging* ; Shoulder Fractures/diagnostic imaging* ; Tomography, X-Ray Computed ; Young Adult