Acute lateral ankle sprain

 

CFLATFLTalar Tilt

 

Definition

 

Partial or complete rupture of one or more of the lateral ligaments of ankle

 

Epidemiology

 

Lateral ankle sprains are the most common ligamentous injuries

ATFL most commonly torn ligament in humans

 

Roos et al Am J Sports Med 2017

- 5 years NCAA

- 2429 lateral ankle sprains

- 480 high ankle sprains

- 380 medial ankle sprains

- basketball most common sport

 

Risk factors

 

Doherty et al Sports Med 2014

- meta-analysis of 181 papers

- incidence of ankle sprains

- females > males

- children > adolescents > adults

- most common in indoor / court sports

 

Natural history

 

van Rijn et al Am J Med 2008

- up to 33% patients still have pain 1 year after acute ankle sprain

- up to 34% risk of recurrent ankle sprain

 

Thompson et al BMC Musculoskeletal Disord 2017

- prognostic factors associated with poor recovery after acute ankle sprain

- female, increased severity, swelling, limited weight bearing

- pain at 3 months

- reinjury within 3 months

- increase number of ligament injuries + bone bruise on MRI

 

Etiology

 

Inversion injury

- jumping sports

- foot plantarflexed and inverted

 

Associations

 

Pes Cavus

Tarsal Coalition

 

Anatomy

 

The ankle is a uniaxial joint that resembles a mortise and tenon

- very stable when loaded in the neutral position

- bony contact and stability decrease with plantar flexion

 

Lateral ligamentsAnkle anatomy

 

 

ATFL

(Anterior talofibular ligament)

CFL

(Calcaneofibular ligament)

PTFL

(Posterior talofibular ligament)

Deltoid
Dimension

15 to 20 mm long

6 to 10 mm wide

2 mm thick on average

Cylindrical

20 to 30 mm long

3 to 5 mm thick

4 to 8 mm wide

30 mm long

5 mm wide

5 to 8 mm thick

20 - 30 mm long

10 mm wide

2 to 3 mm thick

 

Origin

Anterior margin lateral malleolus

1 cm above tip

Tip of lateral malleolus Medial surface lateral malleolus Medial malleolus
Attachment Lateral talar neck

Deep to peroneal tendons

Lateral aspect of calcaneum

13 mm below subtalar joint

Posterior lip of talus

Superficial

- navicular / spring ligament / sustenaculum / calcaneum

Deep

- medial wall of talus

Action Primary restraint to anterior displacement

2.5 x stronger than ATFL

Lateral ankle stability

Strongest

Least often injury

Isolated injury rare

 

Pathology

 

Most are mid-substance tears

- avulsion injuries occur in about 14%

 

Findings

- isolated ATFL tear is most common injury(60% to 70%)

- combined ATFL / CFL tear (20%)

- isolated CFL, PTFL, & subtalar ligament ruptures all very rare

 

Examination

 

Lateral bruiseMedial bruising

 

Lateral ligament complex

- pain / tenderness

- lateral ankle swelling

- ligament testing - anterior drawer / talar tilt

 

Anterior drawer  Talar tilt
Assess ATLF CFL test / subtalar instability

10° plantarflexion neutral rotation

Draw talus anterior to tibia

10-20° plantarflexion

Ankle inversion

> 3mm difference to other ankle > 20o difference to other ankle
Ankle Anterior Drawer Talar Tilt

 

Deltoid ligament

- tenderness / bruising medially

 

Syndesmosis / high ankle sprain

- tender syndesmosis

- pain with external rotation foot

 

Grade

 

Grade I Grade II Grade III

Mild injury

Minimal swelling

Minimal tenderness

Diffuse swelling

Diffuse tenderness

Marked swelling

Negative anterior drawer / talar tilt

Partial ATFL

Positive anterior drawer

Negative talar tilt

ATFL tear +/- partial CFL

Positive anterior drawer

Positive talar tilt

Rupture ATFL & CLF

Normal activities with pain

Cannot perform normal activities

Weight bear with pain

Difficulty weight bearing

 

X-rays

 

Ottawa rules for xray acute ankle sprain

- malleolar bony tenderness

- unable to weight bear

- bony tenderness

 

MRI

 

ATFLATFLATFLATFL

ATFL normal

 

ATFLPTFL

 

ATFLATFLATFLATFL

Torn ATFL

 

CFLCFLCFLCFL

CFL

 

PTFLPTFLPTFLPTFL

PTFL

 

DeltoidDeltoidDeltoidDeltoid

Deltoid ligament

 

Associated injuries

 

Osteochondral lesions

 

Roemer et al AJSM 2014

- MRI of 261 acute ankle sprains

- 40% complete ATFL tear

- 20% syndesmotic injury

- acute lateral talus osteochondral lesions 8%

- chronic lateral talus osteochondral lesions 1%

 

Management

 

Operative versus non operative management

 

Kerkhoffs et al Cochrance Database Systematic Review

- systematic review of operative v nonoperative management acute ankle sprain

- evidence early surgery improves stability

- evidence early surgery associated with longer recovery time / stiffness / complications

 

Non operative management

 

Goals

 

Return to function

Reduce recurrence / chronic ankle instability

 

Acute management

 

MoonbootAnkle Orthosis

 

Seah et al Br Med Bull 2011

- systematic review of acute ankle sprains

- mild / moderate sprains - functional bracing / taping

- severe sprains - air cast for short period

 

Petersen et al Arch Orthop Trauma Surg 2013

- systematic review of 16 prospective RCT

- evidence for semi-rigid bracing for grade I  / II

- evidence for 10 days immobilisation for grade III injuries

 

Prevention of recurrence

 

Brace / taping

 

Janssen et al Br J Sports Med 2014

- brace v proprioception exercises v both

- 384 athletes

- recurrence brace:15%

- recurrence proprioception program: 27%

- recurrence both: 19%

 

Rehabilitation exercises

 

Neuromuscular training / proprioception / postural balance / strengthening

 

Bleakley et al Arch Phys Med Rehab 2019

- systematic review of postural training / strengthening

- 7 RCTs and 1400 patients

- evidence that rehabilitation exercises reduce recurrence at 6 and 12 months

 

Hupperets et al BMJ 2009

- RCT of 522 athletes with acute ankle sprain

- home proprioception program: recurrence 22%

- no home program: recurrence 33%