Sports and Exercise Medicine

Syndesmosis Injuries

Diagnosis, Management and Rehab

o   Syndesmosis injury – also known as “high ankle sprain”

o   0.5% of all ankle sprains without fracture

o   13% with ankle fracture


o   Mechanism  - external rotation, eversion injury

-  External rotation forces talus laterally, pushes fibula away from the tibia.

-  Leads to increased forces within the tibio-talar joint.

-  Stresses ligamentous complexes, congruence of ankle joint, subluxation of the fibula



o   Associated injury

  • osteochondral defect (up to 25%), Peroneal injury (up to 25%), fractures
  • Weber B/C, occult fracture (base 5th metatarsal, anterior calcaneal process, lateral talar process)

o   Watch for deltoid ligament injury  - deep and superficial fibres, avulsion fracture

o   Missed injuries  - ongoing pain, accelerated OA

o  If treated promptly excellent functional outcomes


  • Syndesmosis – several ligaments
    • AITFL (anterior-inferior tibiofibular ligament)
    • PITFL (posterior-inferior tibiofibular ligament) – strongest part
    • Interosseous membrane
    • Interosseous ligament (distal part of interosseous membrane)
    • Inferior transverse ligament


  • Function
    • maintains integrity between tibia and fibula
    • resists axial, rotational and translation forces


  • Symptoms

    • Anterolateral ankle pain
    • Medial ankle pain if deltoid ligament involved
    • Swelling - globally throughout the ankle
    • Pain weight bearing
  • Examination

    • Tender syndesmosis and along interosseous membrane - the higher the tenderness, the worse the prognosis
    • External rotation with dorsiflexion in prone position and bent knee - unable to maintain knee in mid-line
    • Pain on squeeze testing – when squeezing together tibia and fibula at midshaft level, referred pain at the syndesmosis is experienced.
    • Pain on heel raise, inability to heel raise


  • X-ray

- Weight bearing “Mortise” view

- Visualise the opening of the syndesmosis, may need comparison views

  • MRI

- Considered gold standard

- AITFL, PITFL easily visualised. Highly sensitive and specific (fig 2 and table 1)



  • Depends on injury grade as per Modified West Point Classification.
    • Grade I: Sprain AITFL, no instability or diastasis
    • Grade II: Sprain AITFL / IOL, mild instability / no frank diastasis
      • IIA: Normal deltoid, Negative squeeze test
      • IIB: Injured deltoid, positive squeeze test.
    • Grade III: Complete tear, frank instability and diastasis


  • Non-operative for Grades I-IIA, Operative for Grades IIB-III
    • Grades I-IIA

– Progressive rehabilitation. Return to sports @6 weeks

    • Grades IIB-III

– Arthroscopic assessment +/- stabilization. RTS @9 weeks

Surgical Techniques

  • Arthroscopic assessment – When unstable, stabilisation of syndesmosis (Screw / Suture-button) +/- syndesmotic ligaments repair +/- deltoid repair.
  • In chronic injuries (>3 months) – Ligament reconstruction (Tendon autograft)
    • If syndesmotic OA established (and low-demand) – Syndesmotic arthrodesis

Rehabilitation Protocols

  • Surgical stabilisation - period of immobilisation and restricted weight-bearing


  • Progressing to restoration of range of movement, strength and proprioception


  • Eventually sports-specific drills become the focus prior to return to competition.


  • Conservative management


  • Significant syndesmosis injuries can also be successful


  • Carefully selected following MDT discussions


  • Number of factors including function, imaging, sport and often ‘time of season’ and age of player


  • Detail of rehabilitation protocols can differ but the outline framework below gives an insight into the goals of each stage.


- Dr Kal Parmar

- Mr Francesc Malagelada

- Colin Lewin -