Chronic Ankle Instability

Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist
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Chronic ankle instability is a condition characterized by a recurring “giving way” of the outer (lateral) side of the ankle. This condition often develops after repeated ankle sprains. Usually the “giving way” occurs while walking or doing other activities, but it can also happen when you’re just standing. Chronic ankle instability usually occurs because of repeated ankle sprains. Multiple ankle sprains can result in stretched-out ligaments. The issue can also arise from an ankle sprain that has not completely healed yet.

A common symptom of ankle instability is the feeling of the ankle ready to give way. This may be heightened when walking on uneven ground or when wearing high heels. The instability may also be accompanied by pain on the outside of the ankle. Sometimes this pain is intense, and other times it may be a dull ache. Lateral ankle ligament reconstruction is a surgery to tighten and firm up one or more ankle ligaments on the outside of your ankle. It’s also known as the Brostrom procedure. It’s most often done as outpatient surgery, so you can go home the same day.

In patients with CAI, strengthening the muscles around the ankle with well-planned proprioceptive exercises helped the patients return to normal living and sports activities, and prevents unnecessary surgery, especially in cases with functional instability.

Other Names

  • Chronic Lateral Ankle Instability (CLAI)
  • Recurrent ankle sprain

Pathophysiology

  • General
    • The vast majority of cases associated with preceding lateral ankle sprain(s) with failure to recover at least 6 weeks after injury
    • The ankle can not maintain mechanical, functional performance
    • Injury to ATFL and CFL play a critical role in generating CLAI[3]
    • Can be difficult to distinguish ankle instability from subtalar instability
  • Definition
    • Partial or complete incompetence of the ATFL, CFL, or PTFL
    • The ATFL is most commonly injured, followed by CFL (20%), and PTFL (<10%)[4]
  • Functional instability
    • Depends on patient generated reports or complaints without a clear anatomical deficit
    • Characterized by impaired proprioception, diminished neuromuscular control, compromised strength, decreased postural control, tight Achilles tendon and weak peroneal muscles[5]
    • No clinical or radiographic evidence of instability
  • Mechanical instability
    • Instability identified on physical examination and radiographic evaluation
    • Characterized by objective ligament laxity
  • Mixed instability
    • Most cases of CLAI likely a combination of both mechanical and functional instability
  • Rotational ankle instability (RAI)
    • Some CLAI patients have a partial deltoid injury
    • Described as a combination of lesions in the medial (anterior deltoid ligament) and lateral ligament complex
    • Increase in talar rotation due to deltoid “open book” tear of the most anterior component

Associated Conditions

  • Lateral Ankle Sprain
    • About 20% of acute ankle sprains go on to develop chronic ankle instability (need citation)
  • Medial Ankle Sprain
  • Sinus tarsi Syndrome
    • Associated with ankle sprains[6]
  • Osteochondral Defect of the talus
    • The mechanism of instability is not well understood
  • Peroneal Tendinopathy
  • Subtalar Instability

Pathoanatomy

  • Ankle Joint
    • Lateral ligament complex: ATFL, CFL, PTFL
  • History of Lateral Ankle Sprain

Differential Diagnosis

  • Fractures & Dislocations
    • Distal Tibia Fracture
    • Distal Fibular Fracture
    • Talus Fracture
    • Calcaneus Fracture
    • Subtalar Dislocation
    • Ankle Fracture (& Dislocation)
    • Peroneal Subluxation
  • Muscle and Tendon Injuries
    • Peroneal Tendon Injuries
    • Achilles Tendonitis
    • Achilles Tendon Rupture
    • Posterior Tibial Tendon Dysfunction
    • Flexor Hallucis Longus Tendinopathy
  • Ligament Injuries
    • Lateral Ankle Sprain
    • Medial Ankle Sprain
    • Syndesmotic Sprain
    • Chronic Ankle Instability
    • Intersection Syndrome Foot
  • Bursopathies
    • Retrocalcaneal Bursitis
  • Nerve Injuries
    • Peroneal Nerve Injury
    • Tarsal Tunnel Syndrome
  • Arthropathies
    • Osteoarthritis of the Ankle
    • Osteochondral Defect Talus
  • Pediatrics
    • Fifth Metatarsal Apophysitis (Iselin’s Disease)
    • Calcaneal Apophysitis (Sever’s Disease)
  • Other
    • Haglund’s Deformity
    • Posterior Ankle Impingement Syndrome
    • Sinus Tarsi Syndrome

Diagnosis

  • History
    • History of recurrent ankle sprains or severe inversion injury
    • They may describe the ankle as rolling or giving way
    • Often avoid provocative activities (weight-bearing, exercise, uneven surfaces)
    • Associated symptoms in include pain, swelling, occasionally locking
  • Physical Exam: Physical Exam Ankle
    • There may be swelling around the lateral ankle
    • Tenderness at the ligamentous attachments of ATFL, CFL, etc
    • Evaluate for Hindfoot Varus, midfoot cavus
  • Special Tests
    • Anterior Drawer Test Ankle: translate distal tibia posteriorly to evaluate for laxity
    • Anterolateral Drawer Test Ankle: The patient’s foot is in 10-15° of plantar flexion, which translates the rear foot anteriorly
    • Talar Tilt Test: Passively evert while palpating lateral talus
    • Rhombergs Test: may be used to assess proprioception of the joint
    • Peek-a-Boo Sign
    • Coleman Block Test

Radiographs

  • Standard Radiographs Ankle
  • Stress Radiographs Ankle
    • Performed while performing either an anterior drawer (AD) or talar tilt (TT) stress to the joint
    • AD: anterior translation of 10 mm or at least a 5-mm side-to-side difference when comparing the injured and uninjured ankles
    • TT: absolute TT of more than 10° or at least a 5° difference between ankles has been reported to correlate with ankle instability
    • When compared to cadaveric measurements using an Optotrak 3D sensor system, stress views underestimate displacement and angular values[7]
    • Instability on TT appears to correlate with MRI findings (need citation)

MRI

  • Reliable, validated for surgical decision making[8]
    • Sensitivity for identifying ATFL abnormality
    • Anticipates perioperative surgical technique in 90% of patients (repair or reconstruction)
  • Jolman et al retrospective analysis of MRI for CLAI[9]
    • Sensitivity: 82.6%
    • Specificity: 53.3%

Ultrasound

  • Dynamic ultrasound can be used to evaluate ligaments, joint
  • Cho et al compared preoperative dynamic US to stress XR, MRI in 28 patients who underwent arthroscopic repair[10]
    • 100% of patients had a lax, wavy ATFL
    • Affected ATFL stretched to an average of 2.8 ± 0.3 cm under stress compared with only 2.3 ± 0.2 cm on the unaffected side
    • The authors could identify no significant difference in ATFL resting length between the injured and uninjured sides (P = 0.777)

Treatment

Calf raises are a popular exercise amongst many athletes and for good reason: they help build ankle and posterior chain strength and stability. Both of these are important for any sport that requires sudden acceleration and deceleration (sprinting, jumping, landing).

Nonoperative

  • Indications
    • Majority of cases initially
    • Especially true for cases that are thought to be primarily functional
  • Physical Therapy
    • Emphasis on neuromuscular and proprioceptive training
    • Neuromuscular training found to be effective in short term, unknown in long term[11]
  • Ankle Orthotics

Operative

  • Indications
    • Failure of conservative measures
    • Significant mechanical instability
  • Technique
    • Gould modification of Brostrom anatomic reconstruction
    • Tendon transfer and tenodesis (Watson-Jones, Chrisman-Snook, Colville, Evans)

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