Acute Injuries of the Leg, Ankle, and Foot: Introduction
Tibia and fibula are connected by proximal and distal tibiofibular articulations and by an interosseous membrane between the bones through the entire length. The relevant anatomy of the leg is depicted in Figures 28-1, 28-2, 28-3, and 28-4. One head of gastrocnemius muscle arises from the medial and the other from the lateral condyle of the femur. Distally gastrocnemius inserts into the tendon of the Achilles. Achilles tendon is a common tendon formed by the gastrocnemius and soleus muscles which inserts into the posterior calcaneus. Peroneus longus arises from the lateral surface of the fibula and is inserted into the base of the first metatarsal and medial cuneiform. The peroneus brevis originates from the lower two-thirds of the lateral surface of the fibula and is inserted into the base of the fifth metatarsal.
Acute Strains of Gastrocnemius
Acute strains are defined as stretching, partial thickness tears, or full thickness tears of the gastrocnemius muscle, usually of the musculotendinous portion, seen most commonly in adult (older adults) tennis players. It is less common in young athletes but can occur in highly competitive adolescent tennis players.1–3
Strains occur after prolonged play, in fatigued muscle, with forceful and sudden eccentric contraction as in a tennis player running toward the net and then forcefully decelerating to a stop to hit a tough shot. It occurs more commonly in poorly conditioned athletes, and those who play an excessive number of sets.
The athlete will complain of considerable pain over the proximal, usually medial calf extending up to the knee and down the leg. There may be considerable swelling over the medial posterior knee, muscle spasm, tenderness, and the muscle is often firm. If the pain in progressively increasing despite ceasing play and rest with firm muscle, immediate evaluation for acute compartment syndrome should be considered. Pain in the calf is elicited or exaggerated by passive stretch produced by dorsiflexion of ankle.
AP, lateral, and sunrise x-ray views of the knee, and with more distal leg findings, an AP and lateral of the tibia and fibula should be obtained to rule out acute fractures. MRI scan will define the extent of the muscle tear and related hematoma, and can reliably differentiate between muscle tears and other masses or injuries about the knee.
Immediate treatment for the initial 3 to 5 days for acute strain consists of analgesics, local ice application, elevation of the limb, and nonweight-bearing on the injured limb. Treatment then progresses to gentle stretching of the gastrocnemius muscle in 1 to 3 weeks, once the initial swelling and pain have resolved. Some practitioners are reluctant to give NSAIDs early, because of concern of exacerbating bleeding into the muscle and increasing the zone of injury. Most athletes return to full sports participation within a few weeks.
Achilles Tendon Rupture
Achilles tendon rupture is rare in youth sports. In skeletally immature athletes avulsion of the posterior calcaneal apophysis (site of insertion of Achilles tendon) is a more likely injury seen most commonly in jumping sports.2–4
The injury is caused by eccentric overload of the Achilles tendon, often on landing from a jump in sports such as basketball, or from sudden forceful push off as at the start of a run.
The athlete feels as if he were shot in the heel. There may be a loud pop and the athlete will have sudden and severe posterior ankle or distal calf pain. There is localized tenderness, swelling, and ecchymosis. There may be some weak plantar flexion present from the flexor hallucis longus, the plantaris muscle, or the posterior tibialis, but a definite marked decrease in plantar flexion strength is present. Thompson test (Figure 28-5) is positive in complete tears or avulsions. A palpable defect or discontinuity of the tendon can be palpated.
AP, lateral, and mortise views of the ankle are indicated to rule out associated ankle fractures and identify calcaneal apophyseal avulsion. Ultrasound is useful to delineate the tendon defect, is inexpensive, and readily available. MRI scan is rarely indicated, except in cases where other significant soft tissue or osteochondral injuries are suspected.
Immediate treatment consists of analgesics, local application of ice, compression dressing, nonweight-bearing on the injured leg, and applying a posterior splint with the foot and ankle in slight plantar flexion. The athlete is referred to orthopedic surgeon for further management.
Definitive treatment consists of closed casting or repair, though in a young athlete it would be unusual to treat the injury closed. Surgical repair is best performed within a day or so of injury. Recovery takes 3 to 4 months for the tendon to heal, and to recondition the leg and regain plantar flexion of the ankle. Athletes may return to play 4 to 6 months after injury, based on the sport, the degree of the injury and the repair, whether the injury was acute or chronic, and their progress in therapy.
Subluxation or Dislocation of the Peroneal Tendons
The peroneal tendons pass from behind and below the lateral malleolus as they enter the foot. The tendons are anchored by the retinaculum in the peroneal groove. When there is disruption of the retinaculum, the tendons slip out of the groove either subluxing or completely dislocating over the lateral malleolus from the groove. Peroneal tendon subluxation is frequently overlooked in the athlete with persistent lateral ankle pain. Most cases are seen in snow skiing, ice skating, running, basketball, soccer, and football.
In some young athletes there may be a shallow groove for these tendons or a lax or absent peroneal retinaculum. Flat hyperpronated feet may also predispose to the injury. The retinaculum also may tear during forced ankle dorsiflexion. The tendon can subluxate or dislocate with sudden, forced eversion dorsiflexion.
The athlete may present as an acute lateral ankle sprain initially with posterolateral ankle pain and tenderness. More often they will show up weeks to months after the initial injury, with a history of recurrent inversion sprains, lateral instability, and snapping of the ankle. Examination may show tendon subluxation with forceful ankle eversion and dorsiflexion.
X-rays of ankle may show a small bony avulsion off the posterolateral lateral malleolus in approximately 50% of these injuries.
If seen acutely, the athlete’s ankle is placed in a cast in slight inversion and plantar flexion for 6 weeks. High demand athletes usually will need surgery once their tendons begin to subluxate or dislocate. The fibular groove is deepened by advancing a shelf of bone off the fibula in those who are skeletally mature. Skeletally immature athletes sometimes require a reconstruction of the area, such as a Chrisman-Snook or other soft tissue procedure.
Fractures of the Shaft of the Tibia and Fibula
Fractures of the shaft of the tibia in skeletally immature athletes can be either incomplete (torus or greenstick) or complete: 70% are isolated fractures, 50% involve distal third of the tibia, and 39% involve the midshaft. Proximal shaft fractures are uncommon. Fractures of the tibia and fibula are the third most common fractures in children and adolescents and peak incidence is around 8 years of age.5–7
The most common mechanism of isolated tibial fracture is rotational stress, particularly with the distal 1/3 tibia fractures seen in younger children. Injuries to the midshaft and proximal tibia also occur with direct blows or heavy axial loading. Rotational stress causes an oblique or spiral fracture whereas a direct impact causes a transverse or comminuted fracture. Fracture of the proximal fibular shaft around the junction of the proximal and middle third can result from indirect force transmitted to fibula in ankle eversion external rotation sprain (Maisonneuve fracture) (Figure 28-6).
The child will present with a history of leg trauma, and sudden pain and swelling of the leg. The child will not bear weight on the affected limb. The leg will be tender at the fracture site, and with displaced fractures there will be an obvious deformity of the leg. Carefully look for lacerations as the tibia is subcutaneous, and a wound usually indicates an open fracture. Perform neurovascular and soft tissue examination of the entire lower limb and be alert for compartment syndrome.
AP and lateral x-rays of the tibia and fibula with the knee and ankle included and comparison views of the uninjured leg are indicated.
For most closed fractures, the limb is placed in a well-padded long leg splint, with the knee flexed, and the patient nonweight-bearing with crutches. The leg is then iced, elevated, and patient referred to orthopedic surgeon. Because of the risk of compartment syndrome a thorough examination should be conducted, looking for pain with passive motion of the foot and toes, paresthesias, pain out of proportion to the apparent injury, and possible altered sensation in the limb. Late signs of compartment syndrome such as pallor, pulselessness, and inability to move the foot and ankle, usually indicate the muscles are already compromised and compartment releases may not restore function to the limb.
Isolated nondisplaced fracture of the fibula is treated in a short leg walking cast or cast boot for 3 to 4 weeks. Weight bearing is allowed as tolerated. These typically heal in 6 weeks. Nondisplaced or incomplete fractures of the tibia can be treated with a non-weight-bearing long leg cast immobilization for approximately 6 to 8 weeks.
Anatomy of the Ankle Joint Complex
Talocrural (or ankle joint) is formed by the articulation of distal tibia and fibula with proximal surface of the talus (Figures 28-7, 28-8, 28-9, 28-10, and 28-11). Dorsiflexion and plantar flexion occur at the talocrural joint (Figure 28-12). Normal range of active dorsiflexion is between 15 and 25 degrees and that of plantar flexion is between 40 and 55 degrees.2,7 Dorsiflexion is primarily a function of tibialis anterior muscle while plantar flexion is a primarily function of gastrocnemius and soleus muscles.8,9
Subtalar joint is formed by articulation of talus proximally with calcaneus and tarsal navicular distally; thus forming the talocalcaneal and talocalcaneonavicular joints. The movements of inversion and eversion occur at the subtalar joint; inversion is primarily a function of tibialis anterior and posterior muscles while eversion is a function of peroneus longus and peroneus brevis.2,8 Normal range of active nonweight-bearing inversion is between 40 and 60 degrees; that of eversion between 15 degrees and 30 degrees.2,8 Inversion is associated with supination (combined motion of inversion, adduction, plantar flexion) of the foot and eversion is associated with pronation (combined motion of eversion, abduction, and dorsiflexion) of the foot.8,9
Anterior margin of the talar dome is wider than its posterior margin; thus the ankle is most stable in a fully dorsiflexed position (closed-packed position) while relatively more mobile and unstable in plantar flexed position.2,8 This bony congruity provides stability in the closed packed position. Peronei muscles and the anterior talofibular ligament are the main soft tissue stabilizers of the ankle.
The lateral ligament complex consists of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and the posterior talofibular ligament (PTFL). The ATFL restrains anterior displacement of the talus and is the most commonly sprained ligament.1,2,5 Medially, the deltoid ligament is a very strong ligament consisting of superficial and deep components. Deltoid ligament restrains eversion-pronation and anterior displacement of the talus. The distal tibia and fibula are connected by the anterior and posterior inferior tibiofibular ligaments, and distal interosseous ligament which form part of the tibiofibular syndesmosis; the tibia and fibula being connected the entire length by the interosseous membrane.
Observe the gait and ability to bear weight. Inability to bear weight correlates with more severe injury. Ankle is best examined with the patient seated on the examination table with knee flexed at 90 degrees. The injured and uninjured ankle should be compared. Initial assessment of an acute injury should rule out any neurovascular injury. Obvious deformity, rapid development of a large joint effusion, and significant limitation of movements may be associated with fracture or complete tear of one or more ligaments. Most inversion ankle sprains are uncomplicated, not associated with other injuries. In case of joint effusion the soft tissue landmarks around the ankle joint cannot be delineated while in case of just soft tissue swelling with no joint effusion, the anatomical configuration can generally be delineated.
Assess both active and passive range of motion: inversion, eversion, dorsiflexion, and plantar flexion.
Localize tenderness by systematic palpation of malleoli, ligaments, tibio-fibular syndesmosis, talus, calcaneus, tarsal navicular, and base of 5th metatarsal.2,7 Inspect and palpate the Achilles tendon, peroneal tendons around the lateral malleolus, and any swelling or tenderness over the medial aspect of the ankle. In children and adolescents with open distal fibular physis the tenderness is localized approximately 2 cm to 3 cm proximal to the tip of the lateral malleolus, in case of Salter Harris type of fracture of the distal fibular physis. Anterolateral tenderness is typical with sprained ATFL. Tenderness localized over the front of the ankle along the interosseous membrane suggests tibio-fibular syndesmosis injury.7,8,10
Integrity of the ATFL is assessed by the anterior drawer test.8 With patient seated, knee flexed at 90 degrees, the distal leg is stabilized with one hand just above the ankle. With the other hand around the heel, and the foot, in approximately 20-degree plantar flexed position, is moved forward (Figure 28-13). The uninjured ankle is similarly assessed for comparison. Relative increase in anterior motion and a soft end point to the movement are associated with sprained ATFL.
The CFL sprain is rarely an isolated injury; it is typically associated with sprained ATFL. The CFL is assessed by comparison of talar tilt of the injured with the uninjured ankle. Both feet in neutral position are inverted from the front; in case of moderate to severe sprain of CFL there is relatively increased talar tilt (Figure 28-14). In inversion-plantar flexion sprains the ATFL is the first to be sprained followed by the CFL and PTFL in that order.1–3,5
With the patient seated on the examination table with knee at 90 degree flexion, squeeze test is performed by gentle squeeze of the leg at midcalf; pain in the ankle joint is associated with high ankle sprain (Figure 28-15).8,10
External rotation test is performed with the patient seated on the examination table, stabilize the leg with one hand and with the other hand gently externally rotate the foot (Figure 28-16); pain in leg and ankle is associated with injury to the syndemosis).8,10
Acute Ankle Sprains
Ankle sprains refer to acute injuries of ligaments around the ankle joint. Three types of ankle sprains are generally recognized based on the predominant mechanism of injury and the ligaments involved, namely, lateral or inversion sprains, medial or eversion sprains and syndesmotic or “high” ankle sprains.9–18
Overall the ankle is the most commonly injured area in sports and ankle sprains account for 20% to 30% of all musculoskeletal injuries in sports, including high-school and collegiate athletes.1,2 Eighty-five percent of all ankle injuries are sprains. Ankle sprains can affect lateral ligaments, medial ligaments, or the tibiofibular syndesmosis. Eighty five percent of all ankle sprains are lateral or inversion sprains without any associated injuries.2,3 Medial ankle sprains are uncommon and account for less than 15% of all ankle sprains.
True ligament sprains are rare in children and uncommon in adolescents before age 15. The exact incidence of ankle ligament sprains in young children is not known, and children are more likely to have injury to the relatively weaker growth plates around ankle, the distal fibular and tibial physes in case of the inversion injury, than to have a ligament sprain.4 The incidence of ankle injuries is higher in sports involving jumping, running, and sudden change in direction. The highest incidence of ankle injuries has been reported in basketball, followed by volleyball, soccer, and gymnastics.2,5 A history of previous ankle sprain has been shown to be the most important risk factor for a subsequent sprain. Other potential risk factors include tarsal coalition, tight Achilles, ankle ligamentous laxity, weak peronei, low profile boots, and narrow, long cleats.2,5,6