The initial provider correctly identified the metatarsal fracture but was less accurate in identifying this patient's Lisfranc midfoot injury. Had the provider recognized these subtle radiographic irregularities, the patient would have been placed in a well-padded posterior splint or a prefabricated short-leg removable ankle boot/cast (also called a controlled ankle movement [CAM] walker, pneumatic ankle fracture boot, or ankle fracture boot). The patient should have then been made nonweight bearing due to the acute Lisfranc injury. To facilitate nonweight bearing, the patient could be taught to use crutches or a walker if he had the requisite upper-extremity strength. A cast scooter or knee scooter is an alternative for nonweight bearing in patients with lower extremity injuries. The scooter lets patients rest the affected lower leg on a padded surface and propel themselves with the unaffected leg and foot. A scooter requires less upper body strength to maneuver and is more readily adaptable to a variety of age ranges. Ice and elevation are helpful in controlling edema.
On subsequent orthopedic clinic examination and review of the patient's initial radiographs, a CT scan of the foot was ordered to further delineate the extent of the bony midfoot trauma. The patient was placed in a padded posterior splint and made nonweight bearing for 2 weeks. On follow-up examination, the patient's foot pain and swelling had resolved. He was transitioned to a fracture boot and continued nonweight-bearing until 6 weeks postinjury. The patient was allowed to remove the fracture boot to perform range-of-motion ankle exercises and to apply ice to the foot several times a day. Once the metatarsal fractures had healed (6 weeks) the patient was fitted for custom-molded orthotics to better-support the midfoot and started a gradual weight-bearing rehabilitation program. The patient was seen back in the office at regular intervals for examination and follow-up radiographs. By 14 weeks postinjury, his pain and ambulation had improved, and he was allowed to resume modified activities wearing supportive shoes and the custom-molded orthotics.
Injury to the Lisfranc joint is caused by direct/crushing injury or by indirect/axial loading of the tarsometatarsal joint. Lisfranc injury causes significant swelling, pain, and plantar bruising, and complications include associated fractures of the metatarsals and acute compartment syndrome in the foot.4-6 Crush-type Lisfranc injuries to the midfoot have poor outcomes and low return to normal function.
Indirect/axial load injuries to the midfoot occur as result of hyperplantar flexion, for example, in motor vehicle accidents and sports injuries. Indirect injury to the Lisfranc joint has more consistent injury pattern because of the weaker dorsal ligamentous structures of the foot, where the metatarsals will displace dorsally or dorsolaterally depending on force vectors at the time of injury.4-7
Plain radiographs of the foot (weight-bearing anteroposterior [AP], lateral, and 30-degree oblique views) are necessary to adequately evaluate for tarsometatarsal joint injury.7,8 Check that the first through third metatarsals and medial-middle-lateral cuneiforms are appropriately aligned and that the cuboid and the fourth and fifth metatarsal bases align.4,6-9
Remember that the patient may have other foot injuries besides a metatarsal shaft fracture.10 A CT scan may be needed to further evaluate midfoot alignment, bone injury, and fracture to the metatarsal base/cuneiform articulation. In the case of a suspected ligamentous-only Lisfranc injury, some providers may choose to obtain an MRI to better-assess tarsometatarsal ligament injury.
Treatment for a Lisfranc injury varies depending on the extent of injury, duration of injury, associated trauma (such as compartment syndrome or an open fracture), and the patient's physical demands. In patients with ligament-only injuries and no joint displacement, maintaining midfoot integrity by placing the patient in a short-leg cast or fracture boot and making the affected foot nonweight-bearing for 6 to 8 weeks is necessary for successful recovery. After that time, the patient can transition into a custom orthotic and supportive shoe. Return to unrestricted activity can take up to 4 months and in many cases will be at a somewhat reduced level compared with preinjury activity.
In patients with a fracture-dislocation injury, closed versus open reduction and fixation is necessary to restore the integrity of the tarsometatarsal joint. The method of fixation depends on the surgeon's training and expertise. Following surgery, patients are nonweight-bearing for 6 to 8 weeks initially. Complications of foot trauma include post-traumatic arthritis, infection, dysesthesias, and deep vein thrombosis (DVT).1,2,4,6,9,10
CASE 2: ANKLE PAIN
An 18-year-old man on college break presented to the orthopedic clinic near his home 3 days after jumping off a stair about 18 to 24 in high and landing on his right foot.
Immediately upon being injured the patient had acute lateral ankle pain that resolved after 10 minutes of sitting on the floor. However, as the day went on, his symptoms returned and were more severe. He was seen initially in the university health center and was diagnosed with a sprained ankle and started on traditional therapy (rest, ice, elevation, and over-the-counter NSAIDs). The patient stated that no radiographs were taken during this initial visit. By the next day, he was having difficulty walking and increased lateral foot pain but had very little ankle or foot swelling. He returned to the university health center, where a radiograph was obtained and read as negative (Figure 5). Because he was having difficulty walking and his symptoms were not improving, his family requested he return home to be seen in the orthopedic clinic. The patient brought copies of his radiographs for the provider to review.
In the orthopedic clinic, the patient's physical examination showed mild swelling of the right ankle, tenderness in the lateral ankle and calcaneocuboid joint region. His range of motion was normal and he had pain with walking and pain with an anterior drawer test. His pulses and sensations were normal.
The patient suffered a fracture to the anterior process of his calcaneus, which can be mistaken for an ankle sprain in patients with few physical examination findings.
Degan and colleagues treated 18 of 25 patients diagnosed with anterior process fractures by immobilization (weight-bearing status unclear) and all had satisfactory results.11 In most cases, anterior process fractures can be treated nonoperatively. However, consider surgery for patients with large articular fracture fragments, displacement, or who may not be able to adhere to immobilization.4,8,9,11-14
The patient was treated with a fracture boot and allowed to bear weight as tolerated. He was referred to physical therapy for acute treatment and a rehabilitation program. On follow-up examination 3 weeks postinjury, he had no pain with walking and was able to ride a stationary bike without the fracture boot. Follow-up radiographs showed early bone healing in good position. At that point, he was allowed to return to wearing regular shoes. The patient missed his 6-week follow-up appointment. When called, his family stated that he had returned to full activity without pain or limitations.
The anterior calcaneal process is the most-often fractured peripheral structure of the calcaneus. The anterior calcaneal process is a saddle-shaped projection and the inferior portion of the anterior process articulates with the cuboid.15 Various mechanisms can injure the anterior process; the two leading mechanisms are inversion on a plantar-flexed foot and forced dorsiflexion and eversion (for example, in a fall or jump from a height in which the patient lands on a flat foot). Inversion of the plantar-flexed foot also can lead to an avulsion fracture injury of the anterior process. The bifurcate ligament (which attaches the anterior process to the cuboid) is stretched and causes an avulsion fracture.
Patients who injure the anterior calcaneal process will present with symptoms similar to those of a sprained ankle. However, they usually have less swelling and less loss of range of motion compared with patients with ankle sprains. Patients also will have isolated point tenderness in the calcaneocuboid joint and not in the anterior talofibular ligament, calcaneofibular ligament, or posterior talofibular ligament.5
Having a high suspicion for anterior process fractures is the key to early detection and correct treatment. In this case, a careful evaluation of this patient's initial radiograph reveals the wedge-shaped fracture in the anterior process of the calcaneus.
CASE 3: ANKLE AND FOOT PAIN
A 19-year-old woman presented to the orthopedic clinic with continued foot pain and swelling and inability to bear weight. She reported that prescription ibuprofen was effective in controlling her pain.
Five days ago, the patient fell 8 to 10 ft while rock climbing, landing in a standing position on both feet and ankles. She also described a twisting injury mechanism to her left foot. She complained of severe left foot and ankle pain, had significant left foot and ankle swelling, and was unable to bear weight on her left foot. She had pain in her right foot and ankle but this did not limit her ambulation and she had only minimal swelling. She was seen in the ED on the day of her injury and a radiograph of both feet and ankles was obtained and read as negative (Figure 6).
The patient was discharged from the ED with crutches, instructed to increase her weight bearing as her pain allowed, and an elastic wrap was applied to her left foot and ankle to control swelling. She was prescribed analgesia and given discharge instructions for her medication, crutch ambulation, and care of ankle sprains.
In the orthopedic clinic, a review of the patient's initial radiograph revealed that she had suffered a fracture through her anterior calcaneus and the mid portion of her talar dome. Her fall from height, pain level, and left ankle and foot swelling were red flags that should have made the ED provider pay closer attention to her radiographs.
Fractures to the calcaneus and talus are common injuries seen in patients who fall from a height.13-15 The orthopedic provider ordered an MRI of the patient's left ankle to better-assess potential articular surface injury to the patient's talar dome (Figure 7). The MRI did not reveal a displaced fracture or additional articular surface trauma. As an alternative, this patient could have had a CT scan of her ankle/calcaneus to better-assess her talar dome and calcaneus fractures. Due to the symmetric joint surfaces of the calcaneus and talus, this patient was treated conservatively in an ankle fracture boot and made nonweight bearing with crutches and a knee scooter. Her fractures healed within 8 weeks and she returned to normal activity, including rock climbing.
The calcaneus is the most commonly fractured tarsal bone. The usual injury mechanism is impaction as in falls from a height or a motor vehicle accident. Letournel described calcaneus fractures based on having a common fracture line.16 This common fracture line runs anterior to posterior and either passed through the sinus tarsi or the posterior facet (calcaneus). However, due to excessive trauma and the force of injury, secondary fracture lines frequently are seen on radiograph and involve a large surface area of the calcaneus. Fractures through the posterior facet frequently are associated with comminuted fracture patterns, a loss of the normal Bohler angle and crucial angle of Gissane (Figure 8), collapse of the subtalar joint and a varus deformity to the hindfoot.4,5,8,9,12,14,17 Patients who suffer a calcaneus fracture will routinely need a CT scan to better-assess the complexity, displacement, and articular surface of the posterior calcaneal facet.
The goals for treating complex calcaneus fractures are to restore the anatomic alignment, maintain articular surface integrity of the facets (posterior-anterior-lateral), and to restore functional ankle and foot motion.8,12,14,15 A calcaneus fracture that shows comminution, fracture displacement greater than 3 mm, altered hindfoot alignment, or changes the patient's weight-bearing capabilities should be surgically repaired.8,12,14,15 This patient had no fracture displacement or alteration of the weight-bearing surface or hindfoot alignment. All of these findings were consistent with conservative treatment of cast/ankle fracture boot immobilization and nonweight-bearing activity.
Talus fractures also occur as a result of falls from height or high-energy injuries. In most talus fractures, the ankle is in the dorsiflexed position due to the wider anterior portion of the talus nesting into the ankle mortise. Talar body fractures occur less frequently than fractures to the talar neck.18 Talar body fractures involve the ankle joint and the posterior facet (calcaneus-subtalar joint) and require congruent joint surfaces at the time of fracture repair. The patient's fracture line fell behind the lateral process and was therefore considered a talar body fracture. (Fractures anterior to the lateral process are considered talar neck fractures.)
Although this patient's fractures can be seen on plain radiographs, CT is the optimal adjunct diagnostic study. CT allows for better visualization of joint surfaces, better delineates fracture patterns, determines the amount of fracture comminution, and can help with surgical repair planning.8,12,15,18
In the case of calcaneus and talus fractures, acute recognition and appropriate initial management are helpful for improving overall outcomes. Initial treatment for calcaneus or talus fractures should be application of a well-padded low leg posterior splint, which will help minimize pain and reduce the significant tissue swelling customarily associated with these injuries. Elevation and ice application are also helpful to minimize swelling. Patients should be nonweight-bearing until they demonstrate sufficient bone healing on follow-up radiograph. Significant fracture displacement warrants surgical intervention.
Remember that patients who have suffered foot or ankle trauma resulting from a fall from height also can suffer a lumbar vertebral body fracture. Perform a thorough physical examination of the spine and pelvis in these patients. Obtain screening radiographs if there is any question about whether the patient has injured the lumbar spine.
CASE 4: ANKLE PAIN
An 11-year-old girl was referred to the orthopedic clinic from the ED, where she had been treated earlier in the day after falling while playing in a bounce house during a party.
The patient said her left foot caught underneath her when she fell. She complained of ankle pain, had noticeable swelling, and had difficulty walking. Her initial examination and radiograph findings from the ED (Figure 9) revealed a fracture at the base of the fifth metatarsal.
In the orthopedic clinic, the patient's physical examination revealed marked bruising and swelling of the foot and ankle. She was tender over her fifth metatarsal and ankle joint and her range of motion was severely limited due to pain and swelling. Her pedal pulses and sensations were normal.
Review of her initial ED radiographs revealed that in addition to the fifth metatarsal base fracture, the patient also had a triplane injury to the distal tibia and growth plate (physis) (Figures 10 and 11).
Triplane injury treatment depends on the amount of fracture plane displacement and articular surface involvement. Extra-articular fractures with less than 2 mm of displacement can be treated conservatively in long-leg casting for 4 weeks, followed by progression to short-leg cast, then weight bearing once bone healing is noted on radiographs. Fracture displacement of more than 3 mm does not bode well for closed reduction treatment due to instability. The potential for soft tissue interposed at the fracture site and soft-tissue swelling also can complicate closed-reduction maneuvers. Any intra-articular fracture with more than 3 mm of displacement requires surgical correction. Patients who suffer a triplane injury may have permanent physis injury.9,19
Due to displacement of the epiphysis (the distal portion of the bone that is separated from the shaft by the physis), this patient underwent a closed reduction under anesthesia. She was placed in a long-leg cast for 4 weeks, short-leg cast for 4 weeks, and began progressive weight bearing at 6 weeks postinjury. The patient was able to resume full activities without complications.
Traditionally, epiphyseal fractures are defined according to the Salter-Harris classification (Figure 12). However, triplane injuries to the distal tibial epiphysis are complex injuries that do not fit into just one Salter-Harris type. Triplane injuries have three planes of injury involving fracture lines in the sagittal, transverse, and frontal planes.
The amount of energy associated with trauma is thought to have a direct involvement in physis injuries. In children, the distal tibia physis is considerably weaker than the associated ankle ligament structures. The distal tibia is the second most common site of physis injury in children. Closure of the lateral distal tibial physis in boys at a later age contributes to this occurrence.19-23 Distal tibial physis closure starts about age 12 years and is complete by age 14 in girls and 16 in boys. Closure occurs sequentially over about 18 months, starting with the central portion, then anteromedially, posteromedially, and finally laterally.23
A triplane injury on ankle radiographs will appear like a Salter-Harris III fracture on an anteroposterior distal tibial view. On the lateral ankle view, the distal tibia fracture will have a Salter-Harris II configuration. The ankle mortise view will show the sagittal fracture plane and will give the best representation of fracture displacement.7,19-23 Other injuries (tibia shaft fracture, fibula fracture, and Maisonneuve injuries) can be associated with triplane fractures. CT scan will help to identify the extent and involvement of articular surface irregularities in triplane fractures and aid in preoperative planning.
A STEPWISE APPROACH
When assessing a radiograph, start by reviewing each image opposite to the suspected injury site and assessing those structures first. Assess the area of injury last. Pay particular attention to the calcaneus (subtalar joint, Bohler angle, angle of Gissane, and anterior process), ankle mortise area (syndesmosis, talus, and medial/lateral clear spaces), and the midfoot (first through third metatarsal bases should correspond with the medial-middle-lateral cuneiforms and the cuboid and fourth and fifth metatarsal bases should align). All of these are areas where injury can be overlooked.
If a patient has significant trauma to the ankle or foot but has unremarkable plain radiograph findings, reexamine the patient to be sure nothing was overlooked on the initial physical examination. Although comparison views can be beneficial, they are not always necessary to make an accurate assessment, and may not reveal irregularities, especially in patients with Salter-Harris I injuries.5,12,19,23,24 Comparison radiographs, although appropriate in some cases, can expose the patient to additional radiation unnecessarily. Likewise, advanced diagnostic studies are not always necessary.
A working knowledge of the Salter-Harris classification is important when assessing children for possible growth plate injuries. Suspect a growth plate injury if the child has open growth plates, has suffered an injury mechanism that produces pain around a joint, and radiographs are inconclusive regarding fracture. For all patients with foot and ankle injuries, regardless of age, the correct treatment is to immobilize the affected areas, make the patient nonweight bearing, provide some form of analgesia, and arrange for an appropriate follow-up appointment.
Subtle musculoskeletal findings on radiograph are challenging. By understanding how to evaluate a radiograph in conjunction with a good history and physical examination, clinicians can better-recognize foot and ankle injuries and help patients get appropriate care.
1. Watson TS, Shurnas PS, Denker J. Treatment of Lisfranc joint injury: current concepts. J Am Acad Orthop Surg
3. Ross G, Cronin R, Hauzenblas J, Juliano P. Plantar ecchymosis sign: a clinical aid to diagnosis of occult Lisfranc tarsometatarsal injuries. J Orthop Trauma
4. Alexander IJ. The Foot Examination & Diagnosis
. 2nd ed. New York, NY: Churchill Livingston; 1997.
6. Thompson MC, Mormino MA. Injury to the tarsometatarsal joint complex. J Am Acad Orthop Surg
7. Johnson TR, Steinbach LS. Essentials of Musculoskeletal Imaging
. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2004.
8. Stroud CC. Fractures of the Midtarsals, Metatarsals and Phalanges; Foot and Ankle 3 Orthopaedic Knowledge Update
. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2003:57–64.
9. Nelson S, Wongworawat M. Tolerances: An Orthopaedic Reference Manual
. 3rd ed. Loma Linda (Calif.) Press; 2009:56–57,94.
11. Degan TJ, Morrey BF, Braun DP. Surgical excision for anterior-process fractures of the calcaneus. J Bone Joint Surg Am
12. Hatem SF. Imaging of Lisfranc injury and midfoot sprain. Radiol Clin North Am
13. Berkowitz MJ, Kim DH. Process and tubercle fractures of the hindfoot. J Am Acad Orthop Surg
14. Macey LR, Benirschke SK, Sangeorzan BJ, Hansen ST. Acute calcaneal fractures: treatment options and results. J Am Acad Orthop Surg
15. Ishikawa SN. Imaging of the Foot and Ankle, Foot and Ankle 3, Orthopaedic Knowledge Update
. Rosemont, IL: American Academy of Orthopaedic Surgeons; 2003:179–188.
16. Letournel E. Open treatment of acute calcaneal fractures. Clin Orthop Relat Res
19. Rogers LF, Poznanski AK. Imaging of epiphyseal injuries. Radiology
21. Cooperman DR, Spiegel PG, Laros GS. Tibial fractures involving the ankle
in children. The so-called triplane epiphyseal fracture
. J Bone Joint Surg Am
22. Schnetzler KA, Hoernschemeyer D. The pediatric triplane ankle fracture
. J Am Acad Orthop Surg
23. Wuerz TH, Gurd DP. Pediatric physeal ankle fracture
. J Am Acad Orthop Surg
24. Kay RM, Matthys GA. Pediatric ankle
fractures: evaluation and treatment. J Am Acad Orthop Surg
Keywords:Copyright © 2016 American Academy of Physician Assistants
radiograph; foot; ankle; fracture; anterior process calcaneus; cuneiform