lateral ligaments of ankle

Acute injury

definition

·      partial or complete rupture of one or parts of lateral ligament of ankle

·      syn. ankle sprain

epidemiology

·      most commonly involves young males

·      average age 27

·      M:F 2.5:1

·      common injury in sport

·      20% of sporting injuries

·      common in basketball and soccer

aetiology

·      inversion injury

·      predisposed by

·      peroneal muscle weakness

·      pes cavus

pathogenesis

·      lateral ligament complex composed of

·      anterior talofibular lig.

·      calcaneofibular lig.

·      posterior talofibular lig.

·      ligaments under strain when ankle inverted

·      ATF under increased strain when ankle plantarflexed and internally rotated

·      CF under increased strain when ankle dorsiflexed

·      PTF under increased strain when ankle dorsiflexed and externally rotated

·      injury most often occurs when ankle plantarflexed and internally rotated

·      thus ruptures involve

·      isolated ATF (70%)

·      combination of ATF and CF (30%)

·      CF alone (rare)

·      PTF (rare)

clinical
Classification

Grade 1

·      stretch without macroscopic tear

·      little pain, swelling or tenderness

·      slight or no functional loss

·      no instability

Grade 2

·      partial tear

·      moderate pain, swelling and tenderness

·      some loss of motion

·      mild or moderate instability

·      usually is isolated ATF tear

Grade 3

·      complete tear

·      severe pain, swelling and tenderness

·      significant loss of function

·      moderate or severe instability

·      usually is combined ATF and CF tear

Presentation

·      history of going over or twisting

·      may be palpable pop

·      pain and swelling on lateral ankle

Findings

·      tenderness and swelling over involved structure

·      ATF - anterior to lateral malleolus

·      CF - inferior to lateral malleolus

·      instability difficult to elicit because of pain

Radiology

·      usually normal

·      may be osteochondral fracture of medial talus

·      may be avulsion fracture of lateral malleolus

·      stress views difficult to obtain because of pain

treatment

·      three options

·      cast immobilisation

·      function treatment (strapping and early controlled mobilisation)

·      operative repair

Functional treatment

·      method of choice

Technique

·      immediate ice and elevation

·      early weight bearing protected by short period of strapping or bracing

·      early programme of

·      ROM

·      strengthening

·      proprioception

Results

·      metanalysis performed

·      functional treatment superior in

·      time to return to work or physical activity

·      achievement of ROM

·      avoidance of muscle wasting

·      complications

·      no difference in

·      instability (giving way)

·      pain, swelling and stiffness with activity

·      reinjury

·      mechanical stability

Operative repair

·      limited indications

·      large avulsions of bone

·      severe ligamentous damage to both sides of joint

·      recurrent injury

Chronic instability

definition

·      instability due to rupture of one or more parts of lateral ligament

clinical features
History

·      complain of

·      pain and swelling over anterolateral ankle

·      giving way

·      occurs with

·      activity

·      walking on uneven ground

Examination

Local

·      tenderness and swelling over involved ligaments

·      anterior to lateral malleolus for ATF

·      inferior to lateral malleolus for CF

Instability

·       depends on ligaments involved

·      ATF instability

·      anterior subluxation on anterior drawer of talus on tibia with ankle in neutral

·      increased inversion on varus stress with ankle in plantarflexion

·      CF instability

·      increased inversion on varus stress with ankle in dorsiflexion

·      ATF and CF instability

·      increased inversion on varus stress in all positions of ankle

·      anterior drawer

·      positive if > 3 mm

·      lateral tilt

·      positive if > 10o-20o (grey zone)

Radiology

·      plain x-ray usually normal

·      may be osteochondral fracture on medial aspect of talus

·      stress radiographs often diagnostic

·      anterior talar subluxation on anterior drawer

·      lateral talar tilt on varus stress

treatment
Nonoperative

·      rehabilitation programme

·      concentration on stengthening of peroneal tendons

·      shoewear modification

·      laterally flared heel

Operative

·      for failed rehabilitation

·      various techniques

·      modified Brostrum procedure is procedure of choice