B7. Foot fractures and dislocations. Achilles-tendon injuries

Page created on October 25, 2021. Last updated on November 10, 2021 at 20:44

Summary

  • The talus’ blood supply is vulnerable to injury, so talar neck fractures have a high risk of osteonecrosis. Talar fractures occur due to fall or high energy trauma. These fractures are classified according to Hawkin. Treatment is surgical and urgent (< 6 hours).
  • Calcaneal fractures (lover’s fracture) are uncommon but severe and have high risk of complications. Often occuring due to falls, they’re often bilateral. A plantar ecchymosis may be present. Treatment may be conservative or surgical.
  • Fifth metatarsal fractures are common and are predisposed to poor healing. A Jones fracture is a proximal fracture of the second zone of the metatarsal base. They’re treated conservatively, except intraarticular and Jones fractures.
  • There are two major types of dislocations of the foot, subtalar dislocation and Lisfranc injury. Subtalar dislocation is dislocation of the talonavicular and talocalcaneal joints, most commonly in the medial direction. This occurs due to high energy trauma, and presents with a foot locked in supination. It’s managed conservatively, with closed reduction and casting.
  • Lisfranc injury is a dislocation of the tarsometatarsal joint complex which is often associated with fractures. It’s often overlooked but may cause long term complications. Patients have symptoms in the midfoot, and may have plantar ecchymosis. Treatment may be conservative or surgical.
  • Achilles tendon injuries is a common sports injury after rapid acceleration and pivoting. Patients usually describe the sensation of being struck or kicked at the back of the ankle, often with an audible “pop”. A gap in the tendon may be palpated, and Thompson test may be positive. Whether they should be treated conservatively or surgical is controversial. In either case, proper rehabilitation is important.

Foot fractures

Definition and epidemiology

Any bone in the foot may break, but only talus, calcaneus, and 5th metatarsal fractures were included in the lecture. However, I was asked regarding toe fractures on the exam so I’ve included those as well.

The talus is a so-called free-floating bone in the foot and ankle joint, referring to how it doesn’t have any tendons or muscles attaching to it. Its blood supply is vulnerable to injury. Fractures of the talus may involve the talar neck, body, the posterior, medial, or lateral processes, or be transchondral (Flake fracture). Talar neck fractures are at highest risk of causing avascular necrosis.

The calcaneus forms the heel of the foot. Fractures of the calcaneus are uncommon but are usually severe and have high risk of complications, especially intraarticular ones. It’s sometimes called the “lover’s fracture” or “Don Juan fracture”.

The fifth metatarsal is one of the most common sites of fracture of the foot. They’re predisposed to poor healing due to poor blood supply. Fractures can occur in three different areas.

Etiology

Talus fracture can occur due to plantarflexing or dorsiflexing forces, as well as axial forces, usually due to falls from significant height or high energy trauma.

Calcaneus fracture also typically occurs from axial force, usually fall from significant height.

Fifth metatarsal fracture occur due to direct trauma, stress, inversion, or crush.

Fractures of the toes may occur due to direct trauma.

Classification

Talus fractures are classified according to the Hawkin classification.

Fracture Description
Type I Nondisplaced vertical fractures of the neck
Type II Displaced fractures + subluxation or dislocation of the subtalar joint
Type III Fractures with dislocation of both the subtalar and ankle joints

The risk for avascular necrosis increases for each type, ranging from 10% in type I fractures to 90% of Type III fractures.

Calcaneus fractures are classified as extraarticular (1/4 of cases) or intraarticular.

Fifth metatarsal fractures come in three types:

  • Tuberosity avulsion fracture
  • Jones fracture (proximal fracture within 1,5 cm of the tuberosity, the second zone)
  • Midshaft fracture

Clinical features

Typical features of talus and calcaneus fracture are classic signs of fracture, including pain, swelling, and inability to bear weight. In case of talus fracture, the patient may be tender at or below the ankle. Calcaneal fractures may cause a plantar ecchymosis, and the heel may appear to be widened due to the deformity. Fractures of the fifth metatarsal may cause pain along the lateral margin of the foot.

Calcaneus fractures are usually severe, causing severe swelling and pain. Possible early complications include compartment syndrome and skin necrosis. Due to the mechanism (fall from height) calcaneus fractures are often bilateral.

Diagnosis and evaluation

X-ray should often be followed up by CT for talus or calcaneus fractures. X-ray alone is usually sufficient for 5th metatarsal fractures and toe fractures.

Treatment

Talus fractures are treated surgically to prevent avascular necrosis, preferably within 6 hours. Dislocated fractures should be reduced immediately. Surgical treatment involves screw fixation followed by casting.

Calcaneus fractures may be treated conservatively or surgically, depending on their severity and whether they’re intra or extraarticular. Surgical treatment may involve ORIF (with plate fixation) or the Zadravecz technique.

Fifth metatarsal avulsion fractures are treated conservatively (unless intraarticular). Jones fractures are treated with screw fixation or non-weightbearing cast. 5th metatarsal shaft fractures are treated conservatively with cast fixation.

Toe fractures are treated conservatively, with the exception of dislocated fractures of the first toe, which are treated surgically.

Dislocations of the foot

Definition and epidemiology

Subtalar dislocation refers to dislocation of the talonavicular and talocalcaneal joints, causing displacement of the calcaneus, cuboid, navicular, and all of the forefoot from the talus. Dislocation most commonly occurs medially to the talus.

Lisfranc injury is a dislocation of the tarsometatarsal joint complex and is a relatively rare injury. Fractures may also occur. This type of injury is often overlooked but can give long-term complications like osteoarthritis and disability.

Etiology

Subtalar dislocation is usually caused by high energy trauma.

Lisfranc injury may be caused by high or low energy trauma, typically due to axial load on a plantarflexed foot.

Clinical features

Subtalar dislocation presents with a foot locked in supination (in case of medial dislocation).

Lisfranc injuries cause pain and swelling of the midfoot, and inability to bear weight. Plantar ecchymosis is suggestive but not always present (also present in calcaneal fracture).

Diagnosis and evaluation

X-ray is often sufficient, but CT or MRI may be necessary.

Treatment

Subtalar dislocation is managed with closed reduction and cast immobilisation. Sometimes temporary (4 weeks) pinning of the joints may be necessary.

Closed, nondisplaced Lisfranc injuries are managed with closed reduction and casting. Displaced fractures are managed with open reduction and fixation with screw or K-wire.

Achilles tendon injuries

Definition and epidemiology

The Achilles tendon, the largest tendon in the body, may be partially or completely ruptured and is a typical injury of active people. Rupture typically occurs when a sudden stress is applied to an already weakened or degenerated tendon.

Etiology

Sports involving running and rapid acceleration and pivoting, like sprinting, basketball, and football, have higher risk of rupture. Recurrent microtrauma causes degeneration of the tendon, predisposing to rupture.

Clinical features

Patients usually describe the sensation of being struck or kicked at the back of the ankle, often with an audible “pop”. Pain is often present, but not always.

Diagnosis and evaluation

A “gap” or “defect” may be palpated in the tendon at the site of the rupture. Plantar flexion of the ankle is decreased but not completely absent (due to intact tibialis posterior).

Thompson test involves having the patient in prone position with their feet hanging off the table. Then, manually compress the calf. In normal cases this causes plantar flexion of the ankle. If plantar flexion does not occur, the test is positive and indicates Achilles tendon rupture.

Tendon rupture may be diagnosed based on clinical findings, but ultrasound and MRI may be used to assist in the diagnosis.

Treatment

Whether Achilles tendon ruptures should be treated conservatively or operatively is controversial. Previously it was thought that conservative treatment has a higher rate of recurrence, but that may not be true if conservative treatment is followed up by proper rehabilitation. Anyway, both are suitable options. Initial treatment in both cases follows the RICE principle.

Conservative treatment involves casting or bracing. Surgical treatment involves repairing the tendon. Both should be followed up by rehabilitation and physical therapy to achieve maximum potential function and reduce recurrence. If treated conservatively, the foot should be casted or braced in a plantarflexed position for 3 – 4 weeks, followed by a neutral position for some more weeks.


Previous page:
B6. Pilon fracture. Fractures and ligament injuries of the ankle

Next page:
B8. Scapula and clavicle fractures. Dislocation of the AC, SC and shoulder joints.

Parent page:
Traumatology

Leave a Reply

Your email address will not be published.