1. Acute Posterior Ankle Pain in a High School Football Player John Hardin, MA, CSCS, ATC

2. Personal Data/History n A 16 y/o male varsity football player c/o acute postero-medial pain in the right ankle. n The athlete was cutting on a plantar flexed foot, felt a pop, and then experienced immediate pain. n The athlete continued to compete with discomfort.

3. Physical Signs and Symptoms n The athlete presented with exquisite tenderness on palpation of postero- medial aspect of the talus and medial malleolus n No tenderness was present over the lateral aspect of the ankle n Full ROM w/ pain in terminal plantar flexion

4. Past History n Athlete had fractured his os trigonum on the contralateral ankle in a non-sports related injury approximately one month earlier.

5. Physical Signs and Symptoms n No instability with ligament laxity tests n Manual muscle tests (especially DF and PF) were limited by pain. n A biomechanical evaluation revealed a forefoot varus.

6. Differential Diagnoses n Achilles tendon strain n Flexor hallucis longus strain n Tibialis posterior strain n Deltoid ligament (post. tibio-talar) sprain n Os trigonum fx n Osteochondral lesion of talus n Posterior tibio-talar impingement n Posterior talo-calcaneal ligament avulsion

7. Diagnostic Imaging/ Laboratory Tests n X-rays revealed a complete fracture of the os trigonum of the talus.

8. Clinical Course n A course of conservative management including walking boot immobilization for the ankle (neutral position) for three weeks. n Following the removal of the walking boot, he performed pool workouts progressing to running and cutting.

9. Clinical Course n Athlete was fitted with orthotics to correct his forefoot varus. n He was also given stretching and strengthening exercises with emphasis on his posterior ankle/calf musculature

10. Discussion n Os trigonum =Accessory bone found just posterior to talus n Present in 50% of normal feet n It may fuse w/ lateral tubercule or remain as separate ossicle n Os trigonum is round, oval, or triangular and of variable size n It may be considered a non-united portion of the lateral tubercle.

11. Deviated From Expected n The os trigonum is a “normal variant” of bony ankle anatomy n The os trigonum fracture can be easily confused with other posterior pathologies. n Lateral x-rays to confirm diagnosis; Continuing pain w/ neg. x-ray, a bone scan may be a useful evaluative test.

12. Thank you