FOOT AND ANKLE

ANKLE BASICS

100

Name key things to be assessed when completing an ankle exam (any 4)

The examination of the ankle starts with an assessment of deformity, ecchymosis, edema, and perfusion, followed by active and passive range of motion Assessment of point tenderness may localize ligament, bone, or tendon injuries, particularly when the patient is seen early. Palpation should include the medial and lateral collateral ligaments, the syndesmotic ligaments, the inferior and posterior edges of the medial and lateral malleoli, the entire length of the fibula and tibia, the anterior plafond, the medial and lateral dome of the talus (palpable with the ankle in plantar flexion), the base of the fifth metatarsal, the calcaneus, the Achilles tendon, and the peroneal tendons behind the lateral malleolus. Stress testing of the ankle joint, should not be performed until a fracture has been excluded. An evaluation of weight-bearing ability should proceed only if clinical suspicion of a fracture is low, the location of tenderness does not indicate the need for plain radiography, or radiographs have ruled out a fracture

200

Name the different views that make up an ankle radiographic series (All)

The anteroposterior, lateral, and mortise views make up the standard three-view radiographic series of the ankle. The likelihood of missing a subtle fracture is reduced with three views. Subtle fractures can be easily missed on ankle radiographs,

300

Name movements of the ankle joint complex (Any 4)

Ankle movements are complex and often involve more than one joint. It is best to consider the group of joints about the ankle as one unit, the ankle joint complex. This complex, which is made up of the talocrural joints and the talocalcaneal (subtalar) joints, allows movements along several axes of motion. Dorsiflexion and plantar flexion of the ankle joint complex occur primarily at the talocrural joints, rotating about the horizontal axis that passes through the medial and lateral malleoli Motions of the ankle joint complex in conjunction with the midtarsal joints include inversion and eversion, which are rotational movements about the oblique subtalar axis involving the subtalar joint abduction (external rotation) and adduction (internal rotation), which are rotational movements about the longitudinal axis of the tibia The components providing stability to the ankle are best conceptualized as a ringlike structure surrounding the talus Disruption of one element of this ring does not, by itself, induce instability. Injury to one ring element, however, should prompt careful scrutiny for a second injury. Any disruption of two or more elements causes ankle instability and can significantly affect joint function

400

Name fractures identified by the AP view of the ankle (any 3)

The anteroposterior view identifies fractures of the medial and lateral malleoli, anterior tibial tubercle, distal tibia or fibula, talar dome, body and lateral and posterior process of the talus, and calcaneus.

500

Name fractures identified by the lateral views in ankle x-rays (Any 3) Bonus (what else can be seen beyond fractures on lateral views)

What is The lateral view identifies fractures of the anterior and posterior tibial margins, talar neck, posterior talar process, calcaneus, and any anterior or posterior displacement of the talus or pathology involving the talonavicular joint. On this view, any incongruity of the articular space between the talar dome and the distal tibia suggests ankle instability, particularly if narrowing of the anterior joint space is present. The lateral view is also useful in identifying an ankle effusion, which appears as a teardrop-shaped density displacing the normal fat adjacent to the anterior or posterior margin of the joint capsule. The presence of an effusion suggests the possibility of a subtle intra-articular injury, such as an osteochondral lesion of the talar dome.7 The mortise view, which is taken with the ankle in 15 to 25 degrees of internal rotation, is most important for evaluating the congruity of the articular surface between the dome of the talus and the mortise. The lines formed between the articular surfaces should be parallel, the joint space should appear uniform throughout the tibiotalar and talofibular components of the joint, and the medial clear space should not exceed 4 mm

DIAGNOSTIC STRATEGIES

100

Name of ankle view represented here.

What is (Image Slide 1)

200

Name of ankle view represented here.

(Image Slide 2)

300

Name 3 other imaging modalities that can be used to assess ankle injuries

Although plain radiography is the initial imaging modality of choice for ankle injuries, it can miss subtle ankle fractures, stress fractures, or ligamentous injuries. When unexplained symptoms persist after negative or inconclusive findings on plain radiography, other imaging modalities or orthopedic consultation may be advisable. Radionuclide imaging (bone scanning) can detect soft tissue injuries, such as distal syndesmotic disruptions, stress fractures, and osteochondral lesions. Bone scan abnormalities are present once a patient is symptomatic and typically appear 1 to 2 weeks before radiographic evidence of a stress fracture. Because of its high sensitivity, a negative bone scan effectively rules out the diagnosis. Bone scan abnormalities are nonspecific, however, because infections and tumors also can lead to positive results. Bone scanning is not useful for follow-up because abnormalities can persist for up to 1 year after recovery. CT scanning is an excellent modality to delineate abnormalities not identified or incompletely characterized by other imaging techniques. CT can detect small fractures, subtle stress fractures, and ligamentous injuries and can facilitate surgical planning. MRI depicts soft tissue structures such as ligaments and tendons and can also delineate bone marrow changes associated with stress fractures before radiographic abnormalities appear. MRI can be helpful both in guiding management decisions and in following the patient’s response to therapy Other studies not performed in the ED, but done following Orthopedic Surgery consultation include 1. Magnetic Resonance or CT arthrography - evaluates chronic ankle pain, to detect ligamentous injuries, loose bodies, impingements, or osteochrondral lesions 2. CT/ SPECT, which combines CT and radionuclide scanning with single photon emission computed tomography (SPECT), has been shown to increase the diagnostic ability of imaging in osteochondral lesions, stress fractures, impingement syndromes, and osteomyelitis

400

What is the importance of the mortise view, and how is it evaluated?

What is The mortise view, which is taken with the ankle in 15 to 25 degrees of internal rotation, is most important for evaluating the congruity of the articular surface between the dome of the talus and the mortise. The lines formed between the articular surfaces should be parallel. The joint space should appear uniform throughout the tibiotalar and talofibular components of the joint The medial clear space should not exceed 4 mm

500

State (All) criteria for the Ottawa Ankle Rules (including foot criteria)

In most cases of isolated blunt ankle trauma evaluated within 48 hours of injury, the Ottawa Ankle Rules (OAR) should be used to determine whether ankle or foot radiographs are necessary. The OAR state that an ankle radiographic series is required if there is pain in the malleolar region with any of the following findings: 1. Bone tenderness at the posterior edge of the distal 6 cm or the tip of the lateral malleolus, or 2. Bone tenderness at the posterior edge of the distal 6 cm or the tip of the medial malleolus, or 3. Inability to bear weight (defined as the ability to transfer weight onto each leg regardless of limping) for at least four steps both immediately after the injury and at the time of evaluation The OAR further state that a foot radiographic series is required if there is pain in the midfoot region with any of the following findings: 1. Bone tenderness at the navicular bone, or 2. Bone tenderness at the base of the fifth metatarsal, or 3. Inability to bear weight for at least four steps both immediately after the injury and at the time of evaluation The OAR have a sensitivity approaching 100% in detecting malleolar zone ankle fractures and midfoot zone fractures.

PATHOLOGIC CONDITIONS OF THE ANKLE

100

What is the name of the fracture depicted here?

Slide 5 & 6

200

Identify the fracture depicted in the image, and give a brief description of what it is comprised of.

Slide 7 & 8

300

Name ankle fractures for which Orthopedic Surgery consultation in the Emergency Department is recommended (Name at least 4)

(Slide 5) In general, all displaced or potentially unstable ankle fractures require orthopedic consultation in the ED 1. Unimalleolar fractures which include: Displaced medial malleolar fracture Medial malleolar fracture with lateral collateral ligament rupture Displaced lateral malleolar fracture Lateral malleolar fracture with deltoid ligament rupture Lateral malleolar fracture with widened medial clear space Unimalleolar fracture with syndesmotic diastasis Fibula fracture at or proximal to the tibiotalar joint line Displaced posterior malleolar fracture Posterior malleolar fracture involving more than 25% of articular surface 2. All bimalleolar fractures 3. All trimalleolar fractures 4. All intra-articular fractures with step deformity 5. All open fractures 6. All pilon fractures (A Pilon fracture, also called a Plafond fracture, is a fracture of the distal part of the tibia, involving its articular surface at the ankle joint.)

400

Describe the evaluation and management of open fractures. (At least the basics)

Open ankle fractures usually occur from severe isolated ankle injuries or multiple trauma and require immediate orthopedic consultation. After documentation of the neurovascular status and the extent of soft tissue trauma, gross contaminants should be removed from the wound, saline-soaked sterile gauze should be applied, and the injured leg should be splinted. Swabbing wound for bacterial culture and sensitivity testing is unnecessary. If significant deformity is present, immediate reduction before splinting is indicated. Tetanus immunoprophylaxis should be administered as appropriate. Because open fractures are invariably contaminated with bacteria, patients with these injuries should receive intravenous antibiotics. For low-energy injuries with mild to moderate contamination, a first-generation cephalosporin is usually sufficient. Heavily contaminated wounds require the addition of gram-negative bacterial coverage, typically an aminoglycoside. Adding either penicillin G or clindamycin (if penicillin allergic) as a third antibiotic is necessary for farm or soil-related crush injuries, in which contamination with Clostridium perfringens can be present. In addition to the ankle radiographs, radiographs of the foot, tibia, and fibula should be obtained. All open fractures benefit from early surgical intervention for débridement and irrigation, Therefore identification is crucial, and emergency orthopedic consultation must be sought for such injuries.

500

Describe each of the following factors regarding Achilles Tendon Injuries 1. Cause(s) of Achilles tendon ruptures 2. How is it diagnosed - (Include any physical exam findings, or clinical tests) 3. Management of Achilles tendon ruptures

Achilles tendon rupture is most common in middle-aged men, and its causes are multifactorial. This condition s easily misdiagnosed, leading to a delay in therapy, a worse prognosis, and increased morbidity, including chronic weakness and loss of function. In the great majority of cases, a complete transection of the tendon is present; however, partial tears of the Achilles tendon can occur and may be more prone to misdiagnosis. Achilles tendon rupture results from direct trauma or indirectly transmitted forces, including sudden unexpected dorsiflexion, forced dorsiflexion of a plantar-flexed foot, and strong push-off of the foot with simultaneous knee extension and calf contraction (as in a runner accelerating from the starting position). Factors predisposing to Achilles tendon rupture include preexisting disease such as rheumatoid arthritis, systemic lupus erythematosus, gout, hyperparathyroidism, or chronic renal failure, steroid use or injection, fluoroquinolone antibiotic therapy, and previous Achilles tendon rupture. The diagnosis of Achilles tendon rupture is primarily clinical. Patients usually describe a sudden onset of pain at the back of the ankle associated with an audible “pop” or “snap.” , and there is persistent weakness in plantar flexion On examination, a visible and palpable tendon defect may be noted 6 cm proximal to the calcaneal insertion in acute presentations but will be less apparent in delayed presentations because of hematoma or edema. Patient may still have weak plantar flexions present, which often leads to misdiagnosis The classic maneuver to assess the integrity of the Achilles tendon is the Thompson test. (Slide 9) Medical therapy for a patient with an Achilles tendon rupture consists of rest, pain control, serial casting, and rehabilitation to maximize function. Ongoing debate surrounds the issue of whether medical or surgical therapy is more appropriate for this injury

FOOT BASICS

100

Name the 3 anatomic and functional regions of the foot.

The foot is composed of 28 bones and 57 articulations It can be divided into three anatomic and functional regions: The hindfoot, midfoot, and the forefoot the hindfoot, which contains the talus and calcaneus; the midfoot, which contains the navicular, cuboid, and cuneiforms; and the forefoot, which contains the metatarsals, phalanges, and sesamoids. The midtarsal joints (Chopart’s joint) join the hindfoot and midfoot, and the tarsometatarsal joints (Lisfranc’s joint) join the midfoot and forefoot. The inferior aspect of the talus has three articulations with the calcaneus that are collectively known as the subtalar joint.

200

Describe the neurovascular supply of the foot.

The arterial supply to the foot is from the anterior and posterior tibial arteries and the peroneal artery, a proximal branch of the posterior tibial artery. Motor and sensory innervation comes from branches of the deep and superficial peroneal, posterior tibial, saphenous, and sural nerves

300

What are osteochondral lesions?

An osteochondral lesion is an injury or small fracture of the cartilage surface of the talus. it describes injuries of any origin involving the articular surface and/or subchondral region of the talus or tibial plafond and can thus involve cartilage, subchondral bone, or both. These injuries are now thought to be more common than previously appreciated Many synonyms for this entity, including transchondral fracture and dome fracture of the talus, exist. Mechanisms identical to those causing ankle sprains are the most common cause; An osteochondral lesion should be considered in any patient with ligamentous ankle injury accompanied by gross edema and an effusion on plain radiographs.

400

____________________ is defined as an increase in pressure within a confined osseofascial space that impedes neurovascular function, resulting in tissue damage.

Compartment syndrome is defined as an increase in pressure within a confined osseofascial space that impedes neurovascular function, resulting in tissue damage. Compartment syndrome in the foot, as elsewhere in the body, constitutes a medical emergency. Classically, four foot compartments—medial, central, lateral, and interosseous—are described, Pedal compartment syndrome is most commonly caused by significant crush injuries, fractures, or dislocations. Other causes include bleeding disorders, burns, electrical injury, postischemic swelling after arterial injury or thrombosis, drug or alcohol overdose, excessive exercise, and venous obstruction. Pedal compartment syndrome after an ankle sprain has also been reported Damage is related to the duration and magnitude of compartment pressure rise and the arteriovenous gradient. Compartment syndrome can develop anywhere from 2 hours to 6 days after an insult, although the peak incidence is at 15 to 30 hours.

500

_____________________ is a condition involving pain in the presence of trophic changes and vasomotor instability from inappropriate sympathetic nervous system activity and was previously termed “reflex sympathetic dystrophy.”

Complex regional pain syndrome is a condition involving pain in the presence of trophic changes and vasomotor instability from inappropriate sympathetic nervous system activity and was previously termed “reflex sympathetic dystrophy.” Complex regional pain syndrome occurs months after trauma, which may be major, as in a Lisfranc injury, or relatively innocuous. It has many synonyms, including causalgia and Sudeck’s atrophy, and produces pain of a diffuse burning, aching, or searing nature, together with evidence of vasomotor instability. Complex regional pain syndrome should be considered in the differential diagnosis for foot pain after trauma.

PATHOLOGIC CONDITIONS OF THE FOOT

100

Identify the pathology in this picture

Slide 11

200

Identify the pathology in the picture

Slide 13

300

___________________typically causes pain out of proportion to that expected for the injury. The pain is not decreased by immobilization and can be described as a feeling of tautness within the foot

Compartment syndrome typically causes pain out of proportion to that expected for the injury. The pain is not decreased by immobilization and can be described as a feeling of tautness within the foot. In the case of calcaneal fractures, the pain often is a relentless burning involving the entire foot. Physical examination may reveal tense swelling and sensory deficits. Pain is exacerbated by any movement (active or passive) that stretches the muscles of the involved compartment. Passive dorsiflexion of the toes often is painful. Peripheral pulses and capillary refill usually are normal in compartment syndrome and offer no reassurance when present. Presence of an open wound does not guarantee that all compartments are decompressed.

400

________________is obtained by measuring the angle formed by two lines, one between the posterior tuberosity, and the apex of the posterior facet, and the other between the apex of the posterior facet, and the apex of the anterior process, . A value less than 20 degrees suggests a calcaneal compression fracture

(Slide 10) Boehler’s angle is obtained by measuring the angle formed by two lines, one between the posterior tuberosity (A) and the apex of the posterior facet (B) and the other between the apex of the posterior facet (B) and the apex of the anterior process (C). A value less than 20 degrees suggests a calcaneal compression fracture.

500

Describe the details of a calcaneus fracture including 1. The mechanism of injury 2. Radiographic Diagnosis 3. Treatment/Management.

CALCANEUS FRACTURE Most commonly fractured tarsal bone. MECHANISM Usually severe axial load caused by a fall from a significant height. DIAGNOSIS (Slide 10) ■ Bohler’s angle < 20° (angle between a line formed from the posterior tuberosity of the calcaneus and the apex of the posterior facet and a line between the apex of the posterior facet and anterior process of the calcaneus). A Bohler’s angle of 20°–40° is normal (see Figure 4.21). ■ CT scan may be needed to determine if injury is extensive enough to require surgery. TREATMENT ■ Bulky Jones dressing, posterior splint, non-weight-bearing; orthopedic consult. ■ Surgical repair (when needed) is delayed up to 3 weeks until swelling is improved.