Ligaments of the os trigonum: an anatomical study.
PURPOSE
The aim of the study was to examine the ligaments of the os trigonum.


METHODS
The ankle joint magnetic resonance imaging (MRI) of 104 patients with the os trigonum (experimental group) and 104 patients without the os trigonum (control group) were re-reviewed. The connections of the os trigonum and posterior talofibular ligament (PTFL), the fibulotalocalcaneal ligament (FTCL), the paratenon of the Achilles tendon, the posterior talocalcaneal ligament (PTCL), the osteofibrous tunnel of the flexor hallucis longus (OF-FHL) and the flexor retinaculum (FR) were studied.


RESULTS
The os trigonum is connected to structures. The posterior part of the PTFL inserted on the os trigonum in 85.6% of patients, whereas in all patients in the control group, the posterior part of the PTFL inserted on the posterior talar process (p < 0.05). The connection of the PTCL was seen in 94.2% of patients in the experimental group, while it was seen in 90.4% of patients in the control group (p > 0.05). The connection to the FTCL in the experimental group was 89.4%, while in the control group, it was 91.3% (p > 0.05). The communication with the paratenon was seen more often in the control group compared to that in the experimental group (31.7% vs. 63.8%, p < 0.001). The FTCL was prolonged medially into the FR in 85.6% of patients in the experimental group and in 87.5% of patients in the control group (p > 0.05). The flexor hallucis longus (FHL) run at the level of articulation between the os trigonum 63.5% and the posterior process of the talus 25% and less often on the os trigonum 11.5%.


CONCLUSION
The os trigonum is connected with all posterior ankle structures and more connections than previously reported.
['Szaro|Paweł|P|http://orcid.org/0000-0002-0334-7232', 'Ghali Gataa|Khaldun|K|', 'Polaczek|Mateusz|M|']
D000293:Adolescent D000328:Adult D000368:Aged D000843:Ankle Joint D016022:Case-Control Studies D005260:Female D006801:Humans D008023:Ligaments, Articular D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D018482:Muscle, Skeletal D012189:Retrospective Studies D013628:Talus D055815:Young Adult
Ligament Os trigonum Ankle Connections Paratenon