Exam of the Ankle
Anterior Drawer: 2mm of subluxation or dimpling of the anterior skin
Talar Tilt: Tests ATFL and calcaneofibular ligaments. Use same position as ant drawer (foot neutral, knee flexed 90) Force inversion of the foot, test is positive if there is joint instability. Eversion can be used to test the deltoid
Fibular compression: Assesses the integrity of the tibiofibular syndesmotic ligament. Pain felt at the ankle when squeezing the tibia and fibula 6-8 inches below the knee.
Thompson's test: pt prone and foot hanging off the edge of the bed or knee
flexed.
The patient should lie prone on the examination table. The calf should be gently
squeezed by the physician, who watches for plantar flexion in the patient's
foot. If the foot moves, the tendon is presumed to be at least partially intact.
No movement is indicative of rupture, and the test results are considered
abnormal. If the Thompson test is equivocal, a sphygmomanometer should be placed
on the patient's calf and inflated to 100 mm Hg. The affected foot should be
dorsiflexed. The pressure will rise to approximately 140 mm Hg if the tendon is
intact. In a patient with an Achilles rupture, only a flicker of movement on the
pressure gauge is discernible with dorsiflexion. If the diagnosis is still
unclear, an MRI may be helpful.
Eversion-Lift pinky off ground, keep big toe down
Inversion-Lift big toe off ground, keep little toe down
Abduction-Rotate Foot out
Adduction-rotate foot in
Suppination-adduction + inversion
Pronation-abduction + eversion
Ankle is a ring made up of tibia, tibiofibular ligament,
lateral ligaments, calcaneus, and
Dislocations
Medial and posterior are the most common.
Ankle Series: AP, LAT, Mortise (AP c leg internally rotated, Medial space must be <4mm)
(Ann Emed Med 21:384-390, 1992)
Get ankle films if malleolar pain and any of:
1. Tender on posterior edge, tip, or distal 6 cm of lat or medial malleolus
2. Unable to complete 4 steps (2 on bad ankle), now and at scene
Get Foot films as well if midfoot pain and any of:
1. Navicular Tenderness
2. Base of 5th MC tenderness
3. Can not complete 4 steps
Validated in Kiddies (J Accid Emerg Med 16:342)
(J Trauma 2005;59(5):1268)
Indirect Fibular Stress
The malleolar fork is compressed approximately 10 cm proximally to the fibular
tip, avoiding direct palpation of the injured region (Fig. 1). The compression
is executed using the flat of the hand to spread the applied force on a larger
area.
Direct Medial Malleolar Stress
The thumb is pressed flatly on the medial malleolus (Fig. 2). Direct palpation
using the tip of the thumb is avoided.
Compression Stress of the Mid- and Hindfoot
One hand fixes the calcaneus in neutral position and the other hand applies a
sagittal load on the forefoot, so that the mid- and hindfoot are compressed
(Fig. 3).
If any of these clinical examinations caused pain, the diagnosis was acute
fracture. If there was no pain during the examination, the diagnosis was no sign
for acute fracture.
1) fractures of the os trigonum-The os trigonum is an accessory bone (sesamoid) located posterior to the posterior tubercle of the talus. It is present in 5-14% of the population and is frequently unilateral. This accessory bone may be fused to the talus, calcaneus, or both. Patients with a fracture of the os trigonum often give a history of having sustained an ankle sprain weeks to months earlier, at which time radiographs were interpreted as normal. They give a history of persistent posterior and posterolateral ankle pain, swelling, and giving way of the ankle. All had a 25° decrease in plantar flexion of the ankle and pain to palpation posterior to the tibia but anterior to the Achilles tendon. The pain was enhanced by forced plantar flexion of the ankle or resisted plantar flexion of the great toe.
2) Achilles tendon injuries-Physicians miss injuries to the Achilles tendon in 25% of cases, most often due to preservation of foot plantar flexion by the posterior tibial, peroneal, and toe flexor muscles? Patients will often describe the sensation of being kicked or “shot” in the back of the ankle with an immediately ensuing intense pain. Physicians should look for a palpable gap in the tendon and a positive Thompson test, since these are readily apparent in patients with complete rupture. With the patient in a prone position, instruct the patient to flex his knee. When the calf muscles are squeezed against the tibia and fibula, mechanical contraction of the gastrocnemius and soleus muscles occurs. If the Achilles tendon is ruptured, then contraction of the calf muscles will not plantar flex the foot. Incomplete ruptures may present greater diagnostic difficulties. In patients with these injuries, posteriorly located pain, swelling, and ecchymosis may be the only clue.
3) dislocating peroneal tendons-Like Achilles tendon
injuries, damage to the peroneal tendons is easy to overlook. Unfortunately,
this can result in tendon instability and chronic subluxation or actual
dislocation of the tendons. This injury involves the peroneal tendons where
they pass behind and beneath the lateral malleolus. With sudden, forceful
dorsiflexion and eversion of the ankle and the simultaneous, forceful
contraction of the peroneal muscles, the peroneal retinaculum is torn and the
tendons dislocate anteriorly to a position where they overlie the lateral
malleolus. Patients with this type of injury usually present with
Posterolateral or retromalleolar swelling, ecchymosis, and tenderness. This is
in contrast with most lateral ligament injuries in which these signs occur
anterior or inferior to the lateral malleolus. In addition, plantar flexion,
eversion, and dorsiflexion against resistance increase the patient’s pain in
this area and may reproduce the injury in those patients in whom dislocation
with spontaneous relocation occurs. Therapy for peroneal tendon subluxation or
dislocation is controversial. Casting appears to work best in patients who are
not seriously injured in athletics. But in very athletic patients and those who
have associated avulsion fractures, operative repair prevents ankle
instability, recurrent dislocation, and chronic pain.
4) fractures of the fifth metatarsal-Avulsion of the fifth metatarsal by the peroneus brevis tendon is an injury caused by virtually the same mechanism that causes ankle injuries. In the process of ankle inversion, the tendon, which loops under the lateral malleolus, is stretched and avulses its osseous attachment. These avulsion injuries are typically manifested by discrete tenderness over the fifth metatarsal head in association with local swelling.
5) Transchondral talar-dome fractures-occur with inversion and eversion injuries of the ankle but frequently are not diagnosed when the injury occurs because the radiographs do not show the fracture. The injury causes a compression fracture of the articular surface of the talus and secondary changes in the subchondral bone that may not be radiographically evident for many weeks. Although the acute pain and generalized swelling associated with the injury resolve in 2-3 weeks, the patient experiences persistent stiffness. intermittent joint pain, instability, or catching or locking of the ankle. If the patient returns for evaluation six weeks or more after the initial injury, x-rays may reveal a fracture of the talar dome.
6) ankle diastasis-Finally, diastasis of the ankle at the distal tibiofibular joint can occur without fracture. This may result from complete or partial disruption of the ligament complex that forms the tibiofibular syndesmosis. Usually, the interosseous ligament is injured, often in combination with either the ATFL, deltoid ligament, or both. In an injury at the tibiofibular syndesmosis, an oblique x-ray is most informative; look for widening of the syndesmosis beyond the normal 1-2 mm.
Snowboarding is associated with fractures of the lateral process of the talus. These fractures can be missed. They require casting and ortho f/u. Plain films will be negative up to 40% of the time, therefore CT scan is the proper eval if this injury is suspected. (Annals EM 2003; 41:854-858)
Weakest parts of ankle capsule is the ant/post
Lateral is the most commonly injured-
Ant. Talofibular 1st ruptured (most common)
Calcaneofibular 2nd ruptured
Post Talofibular is 3rd ruptured usually c inversion stress
Medial is
1st º sprain gives mild pn, can bear weight, rx c RICE and ACE
2nd swelling, pn, ? fx, pn on stress, give walking boot
3rd Ant drawer is positive, egg shaped swelling, >1 ligament, may need surgery. Post splint
Inject Joint Capsule opposite injury c 5-10 cc
Talar Stress test to inversion and eversion
Ant Drawer- ankle at 90 to leg, knee slightly flexed. One hand on base of tibia, other cups heel, pull anterior
Chondral Fractures-talar dome fx, refer to avoid arthritis
pn c hyperextension, get calcaneal and ankle films, consider CT
Rx c Rice and Bulky jones. Watch for compartment of the foot
Talus
Cast, consult, consider CT
Navicular
AP/Lat/Oblique
Chip fx can just get an ace
Tuberosity or Body needs Cast
Cuboid or Cuneiform
Needs casting
Lisfranc
Medial aspect of middle cuneiform should always be in line c 2nd MT, if not dislocation
Fx of base of 2nd MT equals further joint disruption somewhere
Ortho Consult
Document DP function
AP/Lat/Oblique
ACE, RICE, Refer for possible Casting
Jones/Pseudo-Jones/Avulsion
5th MT avulsion fx is on proximal 1.5 cm of MT, bulky jones
Jones is distal to prox 1.5 cm through tuberosity
Pseudojones-through shaft, distal to tuberosity
AP/Lat/Obl
2-5th-buddy tape 2-3 weeks
Reduce if dislocated
If Sub-ungal hematoma >50%, remove the nail
1st: if comminuted, cast
Film
Can get rubber foreign bodies from punctures through shoes in addition to pseudomonal infections (Foot Ankle Internat 22(5):409, May 2001)
Griseofulvin 500-1000mg po OD or Lamisil
Foot:
FOOT
Adequate imaging of the foot includes an AP, oblique, and lateral view. In
addition to looking for cortical disruptions, examining alignments and measuring
angles are essential in detecting subtle pathology. On the AP view, the lateral
aspects of the first metatarsal and the first cuneiform should align, as should
the medial aspects of the second metatarsal and the second cuneiform (Figure
27). On the oblique view, the medial aspects of the third metatarsal and third
cuneiform should align (Figure 28). On the lateral view, Bohler’s angle is
generated by a line bordering the superior aspect of the posterior calcaneal
tuberosity intersecting a line connecting the superior talar articular surface
with the superior aspect of the anterior calcaneal process. This angle measures
20 to 40 degrees normally (Figure 29).
Figure 27. AP radiograph and diagram of right foot
Figure 28. Oblique radiograph and diagram of right foot
Figure 29. Lateral radiograph and diagram of right foot
The primary high-risk “D”islocation injury of the foot
is a LisFranc injury. This tarsal-metatarsal fracture/ dislocation injury is
initially missed 20% of the time (26). The strongest part of the LisFranc
ligament tethers the second metatarsal base to the distal first cuneiform. This
ligament thus provides stability to the tarsal-metatarsal junction. A LisFranc
injury is best viewed on the AP radiograph showing a break of the second
metatarsal or Lisfranc ligament alone with a subsequent dislocation of the
second through fifth metatarsals (Figure 30). Radiographically, this
tarsal-metatarsal dislocation is present when the second metatarsal no longer
aligns with the second cuneiform on the AP view and/or when the third metatarsal
no longer aligns with the third cuneiform on the oblique view. It is important
to realize that despite normal alignment of the tarsal-metatarsal junction, a
fracture of the second metatarsal base alone at the Lisfranc ligament insertion
site implies a Lisfranc injury because the second and fifth metatarsals are no
longer tethered to the midfoot. Because a LisFranc injury is associated with
compartment syndrome and often requires surgical repair, carefully scrutiny for
this injury pattern is critical.
Figure 30. Lisfranc injury of right foot (AP view)
Further images and discussion of a LisFranc injury may be found in the
EMedHome.com archives for the clinical case discussing this injury.
Two “O”ccult fractures of the foot include the calcaneus and talus fractures.
First, a calcaneus fracture is the most commonly fractured tarsal bone and had
the third highest “miss rate” for fractures in the study by Freed and Shields at
a rate of 10% (10). Commonly this fracture occurs after a patient falls from a
height onto his or her heel. Radiographic findings include a cortical break,
and a Bohler’s angle of less than 20 degrees suggests an impaction fracture
(Figure 31). Calcaneal fractures frequently require CT imaging to further
assess the severity of bony fragmentation.
Figure 31. Calcaneus fracture (Lateral view)
The second “O”ccult fracture, a talus fracture, ranks as
the second most commonly fractured tarsal bone. Anatomically, the talar neck is
the site of the majority of these fractures (Figure 32). By mechanism of
excessive dorsiflexion of the ankle, this injury often occurs in automobile
drivers aggressively stepping on the brakes in a motor vehicle crash and in
snowboarders. Radiographically, cortical breaks can be extremely subtle but
crucial to detect. This applies especially to talar neck fractures because of
the risks of avascular necrosis, subchondral collapse, and degenerative
arthritis.
Figure 32. Talus neck fracture (Lateral view)
And finding only “H”alf of the injuries in the foot is
relevant to calcaneal fractures. Because they often occur from axial loading of
the calcaneus, other axial structures of the body such as the vertebral spine
are prone to fractures. Specifically, thoracolumbar fractures occur in 10% of
patients with calcaneal fractures (Figure 33). Remembering to perform a careful
physical and radiographic examination of the back will help you avoid the common
pitfall of overlooking a thoracolumbar fracture with potential neurological
compromise.
Figure 33. L3 vertebral burst fracture (Lateral view)
SUMMARY
Orthopedic injuries, such as fractures and dislocations, are easily missed
radiographically and are the source of much litigation in the ED. As an EP, it
is important to be aware that plain films are notoriously poor in identifying
fractures, especially of the scaphoid, radial head, femoral neck, and tibial
plateau. Further imaging and/ or a more expedited follow-up with an orthopedist
is essential in these cases. Also, being vigilant of high-risk but
low-visibility injuries on plain radiographs will help reduce misinterpretation
errors. The mnemonic “DOH” can be used to supplement the EP’s current approach
to reading radiographs by asking the following questions: Did I miss a
“D”islocation? Did I miss a frequently-overlooked “O”ccult fracture? And
lastly, did I identify only “H”alf of the injuries currently present?
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Am J Sports Med. 2006 Sep;34(9):1401-12. Epub 2006 Jun 26. Related Articles,
Links
A prospective, randomized clinical investigation of the treatment of first-time
ankle sprains.
Beynnon BD, Renstrom PA, Haugh L, Uh BS, Barker H.
Department of Orthopaedics & Rehabilitation, McClure Musculoskeletal Research
Center, University of Vermont, Burlington, VT 05405-0084, USA. bruce.beynnon@uvm.edu
BACKGROUND: Acute ankle ligament sprains are treated with the use of controlled
mobilization with protection provided by external support (eg, functional
treatment); however, there is little information regarding the best type of
external support to use. HYPOTHESIS: There is no difference between elastic
wrapping, bracing, bracing combined with elastic wrapping, and casting for
treatment of acute, first-time ankle ligament sprains in terms of the time a
patient requires to return to normal function. STUDY DESIGN: Randomized
controlled clinical trial; Level of evidence, 1. METHODS: Patients suffering
their first ligament injury were stratified by the severity of the sprain
(grades I, II, or III) and then randomized to undergo functional treatment with
different types of external supports. The patients completed daily logs until
they returned to normal function and were followed up at 6 months. RESULTS:
Treatment of grade I sprains with the Air-Stirrup brace combined with an elastic
wrap returned subjects to normal walking and stair climbing in half the time
required for those treated with the Air-Stirrup brace alone and in half the time
required for those treated with an elastic wrap alone. Treatment of grade II
sprains with the Air-Stirrup brace combined with the elastic wrap allowed
patients to return to normal walking and stair climbing in the shortest time
interval. Treatment of grade III sprains with the Air-Stirrup brace or a walking
cast for 10 days followed by bracing returned subjects to normal walking and
stair climbing in the same time intervals. The 6-month follow-up of each sprain
severity group revealed no difference between the treatments for frequency of
reinjury, ankle motion, and function. CONCLUSION: Treatment of first-time grade
I and II ankle ligament sprains with the Air-Stirrup brace combined with an
elastic wrap provides earlier return to preinjury function compared to use of
the Air-Stirrup brace alone, an elastic wrap alone, or a walking cast for 10
days.
