1. Ankle Sprain Imitators
Leslie A. Michaud, M.D.
Steadman Hawkins Clinic of the Carolinas
Primary Care Sports Medicine Fellow

2. Foot and ankle Statistics
1982: NCAA develops the ISS (injury surveillance system)
years of ISS data showed that ankle sprains are the most common injury 14.9% of all injuries
Compare to ACL 2.6%
Concussion 5%
39.7% of high school injuries are foot and ankle
Olympic summer games Athens – 22% of injuries were ankle sprains
Olympic winter games Salt Lake City – 25% foot and ankle
Collegiate basketball - higher rate of grade I ankle sprains in women than men
1. Dick R, Agel J, Marshall SW: National Collegiate Athletic Association Injury Surveillance System commentaries:Introduction and methods. J Athl Train 2007;42(2):
2. Hootman JM, Dick R, Agel J:Epidemiology of collegiate injuries for 15sports: Summary and recommendations for injury prevention initiatives. J AthlTrain 2007;42(2):
3. Borowski LA, Yard EE, Fields SK, Comstock RD: The epidemiology of US high school basketball injuries, 2005-
2007. Am J Sports Med 2008;36(12):
4. Badekas T, Papadakis SA, Vergados N,et al: Foot and ankle injuries during the Athens 2004 Olympic Games. J Foot Ankle Res 2009;2:9.
5. Crim JR: Winter sports injuries: The 2002 Winter Olympics experience and a review of the literature. Magn Reson Imaging Clin N Am 2003;11(2):
6. Hosea TM, Carey CC, Harrer MF: The gender issue: Epidemiology of ankle injuries in athletes who participate in basketball. Clin Orthop Relat Res 2000;372:45-49.

3. Tibia Fibula Medial Malleolus Tibial Plafond Lateral Malleolus Talus
Talus is largely covered in cartilage. Subtalar joint: inversion/eversion function of the ankle. Tibial plafond or ceiliing; broader anteriorly
Subtalar joint

5. Resists posterior displacement
Provides stabilization in plantarflexion
ATFL is the weakest of the three and most likely to be injured because in the plantarflexed/inverted foot (the MOI) it is most susceptible
Stabilizes ankle and subtalar joint; especially during inversion

6. Evaluation of Foot and Ankle Injuries
Identify and localize the injured bony and soft-tissue structures
Determine MOI
Clues regarding location and severity of injury
Clues to potential concomitant injuries that may be overlooked
More extensive evaluation in severe sprains
Arouse suspicion of fx or articular injury
1% of ankle sprains are syndesmotic - more common with eversion
Persistent symptoms 4-6 weeks despite appropriate treatment

7. Imitators Osteochondral lesions of the talar dome
Lateral process talar fractures
Peroneal tendon subluxation and dislocation
Base of the 5th metatarsal (avulsion)
Tarsal coalition

8. Osteochondral Lesions of the Talar Dome
Injury to the cartilage and underlying bone of the talus
History of trauma in 98% of lateral dome lesions
70% of medial dome lesions
Trauma is often an inversion-type injury
Initial radiographs often unremarkable
Seen best on mortise view

9. Berndt and Hardy Classification

10. Osteochondral Lesion Presentation
Persistent pain and swelling well after injury
Occasionally will have a slow onset
+/- mechanical symptoms
Intraarticular process

12. Why do we need to catch an osteochondral lesion early?
The fracture damages vascular supply to the subchondral bone
If treated early, capillaries can restore bloodflow
If not, prolonged weight-bearing causes fibrous tissue to accumulate which will block capillary ingrowth
Leading to AVN and later DJD

13. Diagnosis and Treatment
CT or MRI if radiographs negative and suspicion is high
Conservative
Rest and immobilization
Surgical
Drilling
Debridement
Excision of fragment
Osteochondral graft
Immobilization is often casting

14. Lateral Talar Process Fractures
“Snowboarder’s fracture”
Often subtle presentation plain films
Best seen, if at all, on mortise.
Clinically resemble an inversion ankle sprain
Tenderness 1 cm from the tip of the lateral
malleolus at the lateral talus

15. Lateral Talar Process Fracture Facts
24% of talar fractures are at the lateral process
<1% of all ankle injuries are LTP fx
15% are misdiagnosed as ankle sprains
Exam findings: “tenderness 1 cm inferior to tip of lateral malleolus” mimic ATFL
McCrory P, Bladin C: Fractures of the lateral process of the talus: A clinical review. “Snowboarder’s ankle”. Clin J Sport Med 1996;6:
Boon AJ, Smith J, Zobitz ME, Amrami KM: Snowboarder’s talus fracture: Mechanism of injury. Am J Sports Med 2001;29:

17. MOI: dorsiflexion + inversion + ER force
More of an impact or crush injury
Comminution
More often than not have IA involvement

19. Evaluation and Treatment
CT in all cases to determine intraarticular involvement and level of comminution
Conservative
Only for non-displaced
SLNWB cast for 4 weeks
Advance WB in boot for 2 additional weeks
Operative
Excision (fragments <1cm)
ORIF (fragments >1cm)

20. Peroneal Tendon Instability
Subluxation or dislocation
Can be associated with chronic lateral ankle instability
Functional
Mechanical
Previous injury
Concern for degenerative tears of the peroneus brevis tendon
Persistent pain after Grade III sprains is commonly due to incomplete rehab with too early RTP
Peroneal strengthening

21. Brevis and longus originate from the lateral fibula: Brevis to 5th metatarsal base and Longus to 1st metatarsal base. Make up lateral compartment. Innervation is superficial peroneal n. Common n

22. Superficial Peroneal Nerve
Supplies lateral compartment muscles
High incidence of neuropraxia
Grade II and III sprains
Almost all resolve spontaneously with time
Nitz AJ, Dobner JJ, Kersey D: Nerve injury and grades II and III ankle sprains. Am J Sports Med 1985;13(3):

23. History and Physical Exam
Previous inversion injury
Specific activities i.e. dancers
Swelling and possibly ecchymosis (acute) posterior to lateral malleolus
Stress test
Resist dorsiflexion from the plantarflexed position while the foot is in inversion
Varus hindfoot

25. Treatment Conservative Surgical Acute injuries Chronic Reattachment
Reduce tendon and SLWB cast for 6 weeks
50% success rate
Chronic PT
Surgical
Reattachment
Deepen groove
Reroute tendon
Reconstruct retinaculum
Bone block

26. Tarsal Coalition Congenital fusion of tarsal bones Rigid flatfoot
Calcaneus to navicular most common
8-12 years old
Talus to calcaneus
12-15 years old
Rigid flatfoot
“Peroneal spastic flatfoot”

27. Ant-eater sign…. Elongated anterior calcaneal process

28. History and Physical Exam
Lateral ankle pain
Worse with activity
May radiate to calf
Inspect feet
Flat
Hindfoot valgus
No arch with toe raise
Limited subtalar motion
Tight heel cords

30. Evaluation and Treatment
CT or MRI
Looking for other coalitions
Determine size
Conservative
If asymptomatic – observation
Symptomatic – orthotics or casting
Surgical
Resect coalition and interpose with fat graft or EDB tendon
Arthrodesis – not often used
Conservative treatment is successful in many cases

31. Thank you for your attention!
Questions?

32. Bibliography
Dick R, Agel J, Marshall SW: National Collegiate Athletic Association Injury Surveillance System commentaries:Introduction and methods. J Athl Train 2007;42(2):
Hootman JM, Dick R, Agel J:Epidemiology of collegiate injuries for 15sports: Summary and recommendations for injury prevention initiatives. J AthlTrain 2007;42(2):
Borowski LA, Yard EE, Fields SK, Comstock RD: The epidemiology of US high school basketball injuries, 2005-Am J Sports Med 2008;36(12):
Badekas T, Papadakis SA, Vergados N,et al: Foot and ankle injuries during the Athens 2004 Olympic Games. J Foot Ankle Res 2009;2:9.
Crim JR: Winter sports injuries: The 2002 Winter Olympics experience and a review of the literature. Magn Reson Imaging Clin N Am 2003;11(2):
Hosea TM, Carey CC, Harrer MF: The gender issue: Epidemiology of ankle injuries in athletes who participate in basketball. Clin Orthop Relat Res 2000;372:45-49
Anderson RB, Hunt KJ, McCormick JJ. J Am Acad Orthop Surg 2010;18:
McCrory P, Bladin C: Fractures of the lateral process of the talus: A clinical review. “Snowboarder’s ankle”. Clin J Sport Med 1996;6:
Boon AJ, Smith J, Zobitz ME, Amrami KM: Snowboarder’s talus fracture: Mechanism of injury. Am J Sports Med 2001;29:
Weatherby, Brian. “Start Smart: What Every Practitioner Should Know About Treating Foot and Ankle Pain.” Powerpoint presentation.
DeLee and Drez's Orthopaedic Sports Medicine, 3rd ed. Copyright © 2009 Saunders, An Imprint of Elsevier
Renstrom PA: Persistently painful sprained ankle. J Am Acad Orthop Surg 1994;2(5):
Nitz AJ, Dobner JJ, Kersey D: Nerve injury and grades II and III ankle sprains. Am J Sports Med 1985;13(3):