By Gerard Hardisty…

• Chronic Pain After Ankle Sprain

Lateral ankle sprains are the most common sports injury. It has been estimated that worldwide one in 10,000 people a day suffer this injury.

Some athletes don't seek treatment and many who proceed through a functional rehabilitation program achieve a good result, usually returning to their sport within six weeks. However, the incidence of chronic symptoms after treatment of acute lateral ankle injuries is 10 -30 percent.

Causes

• Ligament Instability
• Chronic synovitis
• Missed fractures
  • Talar dome 
  • Anterior process calcaneus 
  • Lateral process talus
•  Peroneal tendon dysfunction
  •  Subluxation/dislocation
  • Tears
•  Tarsal coalition
• Impingement syndromes
  • Anterior
  • Posterior
• Other less common causes

Diagnosis

Most patients have a history of significant inversion sprain. Often the injury was treated inadequately. Rest Ice Compression and Elevation (RICE) is mandatory in the first 48 hours. Most patients with an uncomplicated sprain will be back on their feet, minimally symptomatic, within two weeks. Symptoms are usually pain, swelling and a feeling of the ankle giving way. Recurrent ankle sprains warrant physiotherapy. Symptoms for longer than three months constitute chronic ankle pain. Thorough examination and appropriate investigations will usually isolate the problem.

Investigation

A repeat radiograph should be considered for any persisting and disabling symptoms. Certainly if symptoms persist longer than three months it is mandatory. A usual investigative pathway is:

1. Plain films
2. Bone scan
3. CT scan
4. MRI (in selected cases)

Bone and CT scanning will provide most answers. MRI is not normally necessary but gives excellent visualisation of the soft tissues, particularly tendons. It can be useful in the protracted case without well -localised symptoms. Nucleotide (bone) scanning is an extremely useful technique in localising bone (and soft tissue) pathology to direct the CT scan. It can also be used to assess the significance of abnormalities seen on the plain films. Ultrasound is very operator -dependent but has its uses in diagnosing tendon disorders and fluid collections.

Treatment

Treatment depends on the cause. Briefly, instability often requires stabilisation. Chronic synovitis and anterior impingement often respond to steroid injection but sometimes require arthroscopic resection. Posterior impingement, tarsal coalition and peroneal tendon dysfunction usually require an open procedure.