How To Diagnose Lateral Ankle Injuries

Start Page: 65

Continuing Education Course #135 — October 2005

I am pleased to introduce the latest article, “How To Diagnose Lateral Ankle Injuries,” in our CE series. This series, brought to you by the North American Center for Continuing Medical Education (NACCME), consists of regular CE activities that qualify for one continuing education contact hour (.1 CEU). Readers will not be required to pay a processing fee for this course.

Diagnosing a lateral ankle injury can be challenging. The initial presentation may be deceptive and some injuries may require more advanced imaging to confirm an accurate diagnosis. Addressing these and other key points, Remy Ardizzone, DPM, and Ronald L. Valmassy, DPM, provide a comprehensive guide to these common injuries that range from chronic lateral ankle instability to peroneal tendon injuries.

At the end of this article, you’ll find a 10-question exam. Please mark your responses on the enclosed postcard and return it to NACCME. This course will be posted on Podiatry Today’s Web site (www.podiatrytoday.com) roughly one month after the publication date. I hope this CE series contributes to your clinical skills.

Sincerely,

Jeff A. Hall
Executive Editor
Podiatry Today

INSTRUCTIONS: Physicians may receive one continuing education contact hour (.1 CEU) by reading the article on pg. 66 and successfully answering the questions on pg. 74. Use the enclosed card provided to submit your answers or log on to www.podiatrytoday.com and respond via fax to (610) 560-0502.
ACCREDITATION: NACCME is approved by the Council on Podiatric Medical Education as a sponsor of continuing education in podiatric medicine.
DESIGNATION: This activity is approved for 1 continuing education contact hour or .1 CEU.
DISCLOSURE POLICY: All faculty participating in Continuing Education programs sponsored by NACCME are expected to disclose to the audience any real or apparent conflicts of interest related to the content of their presentation.
DISCLOSURE STATEMENTS: Drs. Ardizzone and Valmassy have disclosed that they have no significant financial relationship with any organization that could be perceived as a real or apparent conflict of interest in the context of the subject of their presentation.
GRADING: Answers to the CE exam will be graded by NACCME. Within 60 days, you will be advised that you have passed or failed the exam. A score of 70 percent or above will comprise a passing grade. A certificate will be awarded to participants who successfully complete the exam.
TARGET AUDIENCE: Podiatrists.
RELEASE DATE: October 2005.
EXPIRATION DATE: October 31, 2006.
LEARNING OBJECTIVES: At the conclusion of this activity, participants should be able to:
• differentiate among grade 1, grade 2 and grade 3 injuries to the lateral collateral ligaments;
• discuss common physical examination findings with chronic lateral ankle instability;
• assess findings from talar tilt and anterior drawer tests;
• discuss contributing factors to peroneal tendon injuries; and
• assess the potential benefits of orthotics as an adjunctive treatment for lateral ankle sprains.

Sponsored by the North American Center for Continuing Medical Education.

Here one can see an acute ankle injury. Once one has ruled out a fracture, acute or chronic lateral ankle injuries represent a diagnostic challenge.
This manual talar tilt/inversion stress radiograph shows excessive talar inversion within the ankle mortise. Note the intraarticular loose body in the lateral gutter.
This manual anterior drawer stress radiograph demonstrates incompetence of the anterior talofibular ligament.
Here one can see a peroneal tenogram showing extensive stenosing tenosynovitis and adhesions.
On this T1-weighted MRI image, one can see a partial tear to the anterior talofibular ligament and a shallow fibular groove.
Here is an extensive talar osteochondral defect on a T1-weighted MRI sequence.
Here one can see a compensated rigid forefoot valgus with an inverted calcaneus.
74
Author(s): 
By Remy Ardizzone, DPM, and Ronald L. Valmassy, DPM

   The initial presentation of an acute lateral ankle injury may be deceptive. What appears to be a simple ankle sprain may represent a fracture of the ankle or hindfoot. A tendon or impingement-type injury may not present until later in the healing process. One may not be able to appreciate other intraarticular injuries without advanced imaging studies. Nerve injuries may offer the greatest diagnostic challenges of all (see “A Guide To Differential Diagnosis Of Inversion Ankle Injuries” below).

   The ankle is the most common joint injured in sports and ankle sprains represent 85 percent of all ankle injuries in the United States.1-5 When approaching any lateral ankle injury, it is important to ascertain whether it represents an acute or overuse injury.

   When evaluating an acute injury, it is important to perform a thorough physical examination and rule out the possibility of fracture. Swelling and ecchymosis may not correlate to the location of injury. Standard ankle series radiographs, including anterior-posterior, oblique and lateral views, will provide evidence of fracture to the lateral malleolus, posterior and lateral talar processes, and anterior processes of the calcaneus. If physical examination findings warrant, obtaining additional radiographs of the foot may be necessary to rule out fracture to the fifth metatarsal base as well.

   While an inversion ankle injury commonly leads to injury to the lateral collateral ankle ligaments, many other structures in this area may also be injured.1,6-8 One may not appreciate these associated injuries until weeks or months after the initial event. Other associated lateral ankle injuries do not manifest themselves until the patient attempts to return to full activities but is unable to do so due to persistent lateral ankle pain. Typical associated injuries include chronic lateral ankle instability, injury to the peroneal tendons, nerve injury or intraarticular injury.

Weighing The Etiology And Impact Of Chronic Lateral Ankle Instability

   Following an inversion ankle sprain and particularly following repeated inversion ankle sprains, there is a risk of developing chronic lateral ankle instability due to repeated stretching or tearing of the lateral collateral ankle ligaments.

   The lateral collateral ankle ligaments consist of the anterior talofibular ligament, the calcaneofibular ligament and the posterior talofibular ligament. Typically, an inversion ankle sprain results in injury to either the anterior talofibular ligament or calcaneofibular ligaments.9 Frequently, both of these ligaments will be injured to some degree.1 Given its location deep to the peroneal tendons in the posterior ankle, the posterior talofibular ligament rarely sustains significant injury.3 By contrast, the anterior talofibular ligament is the most frequently injured ligament in the lateral ankle. It is also the only one of these three ligaments that is intracapsular.6

   Injuries to the lateral collateral ligaments are typically classified as grade 1, 2 or 3.10 Grade 1 injuries are characterized by stretching or inflammation of one or more of the ligaments. Grade 2 injuries, which are most common, consist of partial tearing of one or more of the ligaments. Grade 3 injuries involve complete rupture of one or more of the ligaments. Early reduction of swelling and prompt initiation of physical therapy are key to regaining full function and stability.1 Outcome studies of grade 3 injuries have shown little difference between conservative and surgical treatment in terms of stability, strength and one’s ability to return to full activities.11

image description image description


Post new comment

  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.

More information about formatting options

Image CAPTCHA
Enter the characters shown in the image.