Following our previous post, this article looks at when a simple ankle sprain is more complicated. The injuries discussed are less common than lateral ankle sprains but can be problematic if missed or not treated properly. Diagnosis of all the below conditions requires a comprehensive clinical assessment and an ultrasound from an experienced clinician.

Medial (Deltoid) Ankle Sprain

A medial ankle sprain is overstretching/injury of the ligament on the inside of your ankle. Damage happens when your ankle rolls outwards under force. Luckily the deltoid ligament is stronger than the outside ankle ligaments, so it’s uncommon to injure it by rolling your ankle inwards.

Ultrasound is excellent for assessing the deltoid ligament before needing an MRI.

Often deltoid sprains happen simultaneously with a Maisonneuve fracture – a break in the top third of the fibular (bone on the outside of your leg) and can mean the ankle is unstable. This needs an ankle specialist review to determine if surgery is required.

If there is no fracture, this injury can be managed similarly to a lateral ankle sprain with clinician guided rehabilitation.

High ankle or Syndesmosis Injury

The syndesmosis is a fibrous structure that makes up part of the roof of your ankle joint. It has three parts:

  1. your interosseous membrane
  2. your anterior inferior talofibular ligament
  3. your posterior inferior talofibular ligament.

The syndesmosis is vital for ankle stability.

Syndesmosis injuries are common in sports such as football and skiing but only happen in 0.5% of all ankle sprains without fracture. It is caused by the rotation of the foot away from the body under load. Symptoms include:

  • pain on touching the involved ligaments
  • swelling (commonly less than in a lateral ankle sprain)
  • bruising (higher up on the ankle than a lateral ankle sprain).

Syndesmosis injuries are either:

  • stable – need rehabilitation
  • unstable – need surgery

A weight-bearing x-ray can partly assess the stability of the ankle joint. An unstable ankle will have more space than usual between the tibia and fibula. MRI is usually required for grading this injury and determining the need for surgery.

Rehabilitation can take twice as long as a lateral ankle sprain, and not rehabilitating can cause early-onset arthritis. Surgery for higher grade injuries is designed to reduce the risk of long-term arthritis.

Persistent ankle pain

Is pain experienced beyond the expected time frames after a lateral ankle sprain. It might be felt in the front, the inside, the outside or the back of the ankle. You might have ongoing ankle instability (your ankle rolls regularly), swelling and struggle to complete your normal activities.

Causes of persistent pain can be:

  • Undiagnosed bone injury or fracture
  • Chronic (long term) ligament dysfunction
  • Tendon inflammation or tears (tibialis posterior or peroneal tendons)
  • Joint capsule inflammation (synovitis)
  • Nerve issues
  • Bone impingement or spurs

X-rays show fractures or bone abnormalities that can cause impingement; it will not show any damage to cartilage, ligaments or tendons. MRI is best for detecting injury to the bone surface. Ultrasound shows damage or dysfunction of soft tissue, including subluxing tendons

A course of guided rehabilitation to address any range of movement restrictions, muscle imbalances, or poor movement patterns can significantly improve persistent pain. An excellent clinical therapist will guide you when to seek an ankle specialist review.

Recurrent ankle sprain

Recurrent ankle sprains or chronic ankle instability is when you feel as if you cannot trust your ankle. It feels unstable and weak.

You will have difficulty and feel uncomfortable:

  • Walking on uneven ground
  • Stopping or starting suddenly
  • Pushing off quickly to run

After a lateral ankle sprain, not completing rehabilitation can lead to recurrent ankle sprains. Regularly rolling your ankle causes more and more damage to your ligaments, and they often don’t fully recover, becoming permanently longer and weaker than usual. This leaves your ankle joint surfaces at higher risk of being damaged, which can cause early-onset ankle arthritis (i.e. in your 40s or 50s.)

A course of guided rehabilitation is the first step to address ankle instability. Your treating clinician can determine if bracing is suitable. If rehabilitation fails to reduce symptoms, then surgery to stabilise your ankle may be indicated, and you should see an ankle specialist.