Anatomy of the os trigonum

Area of Science:

• Orthopedic Surgery
• Pediatric Radiology
• Developmental Anatomy

Background:

• The os trigonum is a common accessory ossicle in the foot.
• Its exact developmental relationship with the talus in skeletally immature individuals requires clarification.
• Understanding its anatomy is crucial for diagnosing foot pain in children.

Purpose of the Study:

• To describe the anatomic and cartilaginous relationship between the os trigonum and the talus in skeletally immature patients.
• To characterize the os trigonum as a potential secondary ossification center.
• To compare potential injury patterns of the os trigonum synchondrosis to other similar structures.

Main Methods:

• Examination of three anatomic specimens of os trigonum from skeletally immature patients.
• Histologic analysis to determine the nature of the connection between the os trigonum and the talus.
• Comparative analysis with known ossification centers and injury patterns.

Main Results:

• Demonstrated anatomic continuity of the os trigonum's cartilage with the talus.
• Identified a synchondrosis between the ossicle and the talus.
• The os trigonum may function analogously to a secondary ossification center, with potential for stress or acute fracture.

Conclusions:

• The os trigonum in immature patients is connected to the talus via a synchondrosis.
• This synchondrosis represents a vulnerable site for fractures, similar to accessory navicular injuries.
• This finding has implications for understanding pediatric foot pain and injuries.