Ankle Impingement

 

Introduction

Ankle impingement is a painful mechanical limitation of full ankle range of motion secondary to an osseous or soft-tissue abnormality.

The leading causes of impingement lesions are post-traumatic; however, other causes include infection, inflammatory arthritis and degenerative disease.

Classification is based on anatomical location of the impingement.

 

Anterior

Occurs in ankle dorsiflexion

Common in athletes - also known as "Footballer's ankle":

  • repetitive microtrauma / traction injuries to the anterior capsule
  • can result in inflammation or synovitis that gets pinched during forced dorsiflexion = soft tissue impingement
  • local ossification results in bone spurs along the anterior joint line that block dorsiflexion = bony impingement

Although often described as 'kissing osteophytes' on lateral x-rays, CT scans suggest that talar osteophytes tend to be more medial, while tibial ones are more lateral. 

May be associated with:

  • chronic ankle instability - a deficient ATFL may allow the talus to extrude anteriorly during dorsiflexion
  • post-traumatic fibrous bands / synovial plica
  • thickening of the ATFL

Symptoms

Anterior ankle pain on:

  • forced dorsiflexion
  • walking upstairs / uphill
  • deep squatting

 

Posterior

Occurs during plantarflexion (also known as talar compression syndrome)

Common in ballet dancers

Causes

  • soft tissue impingement / compression
  • os trigonum
  • lateral talar process enlargement (Stieda process) or fracture
  • osteophytes
  • malunion of posterior malleolus / talus / calcaneum fracture

Symptoms

Posterior ankle pain on:

  • walking downstairs / downhill
  • high-heeled shoes
  • plantar flexion activities (e.g. ballet / yoga)​

May be confused with Achilles pathology, FHL tendinopathy, or subtalar joint arthritis

 

Examination

  • 'Impingement test':
    • relax ankle / Achilles
    • forced passive plantar/ dorsi flexion 
    • can repeat with examiner's thumb pressing on site of pain - this often recreates symptoms
  • Palpable osteophytes / bony prominence
  • Look for other pathologies:
    • ankle instability
    • peroneal tendinopathy
    • Achilles pathology
    • subtalar arthritis

 

Imaging

  • X-rays: standing AP + lateral
  • CT: high resolution 3D imaging of osseous structures e.g. posterior talar process
  • MRI: demonstrates soft tissue changes, bone marrow oedema, osteochondral lesions
  • Dynamic US: has been used to visualise impingement 

 

Treatment​

Non-operative

  • ​Acute
    • rest, ice, NSAIDs, splintage
  • Chronic
    • activity modification
    • orthoses (e.g. heel raise to reduce anterior impingement)
    • physio (e.g. peroneal compartment strengthening)
    • corticosteroid injections (for soft tissue impingement)

Operative

For persistent symptoms that:

  • do not respond to non-operative treatment
  • interfere with daily activities or athletic performance

Also deal with co-existing pathology (e.g. lateral ligament reconstruction)

Consider intra-operative fluoroscopy to confirm adequate bony excision

Arthroscopy

  • mainstay of treatment
  • debridement of osteophytes (cheilectomy) - burr or osteotomes
  • shaving of inflamed synovium
  • visualisation and assessment of the joint surfaces

Open

  • more often for posterior impingement (posteromedial or posterolateral)
  • may be better for large bony lesions
    • e.g. Stieda process

 

Outcomes

  • Generally good to excellent in short to mid-term
  • Return to play 6-12 weeks
  • Later deterioration probably reflects underlying joint damage and/or co-existing pathologies

​

References

  • Bassett FH 3rd, Gates HS 3rd, Billys JB, Morris HB, Nikolaou PK. Talar impingement by the anteroinferior tibiofibular ligament. A cause of chronic pain in the ankle after inversion sprain. J Bone Joint Surg Am. 1990 Jan. 72(1):55-9.
  • Hamilton WG. Tendonitis about the ankle joint in classical ballet dancers. Am J Sports Med. 1977 Mar-Apr. 5(2):84-8.
  • Zwiers R, et al. Arthroscopic treatment for anterior ankle impingement: a systematic review of the current literature. Arthroscopy. 2015;31(8):1585–96.
  • Zwiers R, et al. Surgical treatment for posterior ankle impingement. Arthroscopy. 2013;29(7):1263–70.
  • Brennan SA, Rahim F, Dowling J, Kearns SR. Arthroscopic debridement for soft tissue ankle impingement. Ir J Med Sci 2012;181(2):253–6.
  • Parma A, Buda R, Vannini F, Ruffilli A, Cavallo M, Ferruzzi A, et al. Arthroscopic treatment of ankle anterior bony impingement: the long-term clinical outcome. Foot Ankle Int 2014;35(2):148–55.
  • Calder JD, Sexton SA, Pearce CJ. Return to training and playing after posterior ankle arthroscopy for posterior impingement in elite professional soccer. Am J Sports Med 2010;38:120–4.