Acute Injury



Partial or complete rupture of one or parts of lateral ligaments of ankle

- common ankle sprain




Lateral ligaments sprains are the most common ligamentous injuries of the human body

- account for approximately 15% of all athletic injuries

- it is estimated that there is one ankle inversion injury per day per 10,000 people


Most common young males

- average age 27

- M:F 2.5 : 1

- common injury in sport 

- basketball & soccer

- 10% emergency consults




Up to 20% to 40% of ankle sprains treated conservatively have some residual symptoms

- undertreatment is more common than overtreatment

- inadequate treatment can result in chronic ankle instability with recurrent sprains and early degenerative arthritis

- 10% of lateral ligament injuries will have subtalar instability also




Inversion injury

- jumping sports

- land plantarflexed and inverted




Peroneal muscle weakness

Pes Cavus

Tarsal Coalition




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


It is very stable when loaded in the neutral position

- bony contact and stability decrease with plantar flexion


1.  ATFL 


The most frequently injured ligament in the human body



- 15 to 20 mm long, 6 to 10 mm wide, and 2 mm thick on average



- arises anterior aspect fibula, 1 cm above tip, 2 cm long, attaches 8 mm above STJ



- primary restraint to anterior displacement, internal rotation, and inversion of the talus at all flexion angles

- in cadaveric studies, the ATFL always failed first


2.  CFL 


Cylindrical structure

- lies deep to the peroneal tendons

- 2.5 times stronger than the ATFL



- 20 to 30 mm long, 3 to 5 mm thick, and 4 to 8 mm wide



- arises tip fibular, 2 cm long

- subtends angle 130 degrees from fibula

- attaches 13 mm below STJ



- crosses two joints and acts as a subtalar joint stabilizer

- isolated CFL ruptures rare

- the ATFL and the CFL function together at all positions of ankle flexion to provide lateral ankle stability  


3.  PTFL 


The strongest of the lateral ligaments

- least often injured



- 30 mm long, 5 mm wide, and 5 to 8 mm thick



- medial surface of lateral malleolus to posterior lip talus


Ankle MRI PTFLMRI Ankle Intact PTFL




Most are mid-substance tears

- avulsion injuries occur in about 14%



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

- combined ATFL / CFL tear (20%)

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






Fingertip palpation of all structures 

- shown to be almost as accurate and more cost-effective than the tests available


Instability testing


Controversial & unreliable without anaesthesia in acute setting  (LA or GA)


1.  Anterior drawer 


Most important & best predictor ATFL

- 10° plantarflexion neutral rotation

- CFL plays no role


> 3mm is positive


Ankle Anterior Drawer


2.  Talar tilt 


CFL test / subtalar instability

- 10% of patients with lateral ligament instability also have subtalar instability


Patient seated / foot unsupported

- 10-20° PF

- stabilise tibia /  gentle inversion

- compare to other side


> 20o abnormal


Talar Tilt






Advisable with significant ankle injuries / unable to weight bear

- AP, Mortise & Lateral views

- +/- AP Foot


Look for OCD / Weber A fibula


High resolution CT & MRI


Exclude OCD if needed

Not required acutely

Define injury in chronic situation


Grading Acute Injury


Grade I 


Mild injury with minimal swelling and tenderness and slight or no functional loss

- ankle is stable 

- negative drawer and talar tilt tests


Considered to be a partial tear

- patient can perform normal activities but with pain


Grade II 


Moderate injury with diffuse swelling and tenderness

- moderate functional loss with difficulty with toe walking

- partial stability is lost 

- mildly positive anterior drawer  (ATFL complete tear) 

- negative talar tilt (CFL partial tear only)


Partial to possibly complete tear of the ATFL and a possible partial tear of the CFL

- patient cannot perform normal activities and can bear weight but with increased pain


Grade III 


Severe injury

- significant functional loss and marked tenderness, swelling, and pain

- lateral ankle stability is lost 

- positive drawer and talar tilt tests


Considered to signify a double ligament injury with complete rupture of the ATFL and CFL

- weight bearing is usually not tolerated


Acute Management


Grade I & II Injuries 


Mechanically stable 


Benefit from protection 

- stirrup-type brace or high boot

- until nonprotected weight bearing is relatively pain-free


Ankle Orthosis


During the protected period 

- non-weightbearing ROM exercises are performed


Progressing to proprioceptive & ultimately agility training

- shown to shorten the period of disability

- Grade I ankle sprain should be near full recovery at 1-2 weeks

- Grade II ankle sprain at 2-3 weeks (may take a lot longer)


Grade III Injuries


Mechanically unstable by definition


Previously thought to all require surgery but now shown to be successfully treated non-operatively


1.  Casting for 4-6 weeks 

- in slight dorsiflexion & eversion to approximate ligament ends

- then functional rehabilitation


2.  Functional Bracing

- removable brace

- progressive weightbearing

- ROM, proprioception & strengthening exercises

- success demonstrated with MRI studies






Kannus Meta-analysis


Functional treatment superior in

- time to return to work

- physical activity


- less wasting

- complications


No difference in

- instability 

- pain, swelling & stiffness

- re-injury





- figure 8 weave

- in neutral DF & slight ER

- shortens ATFL & helps proprioception



- peronei rehab is the key

- proprioception exercises


Return to Sport 

- successful performance of simple tests provide adequate guidelines

- ability to run, cut and jump 10 times on the single injured foot

- to stand on one foot with eyes closed for one minute 

- all without excessive pain

- athletes can return to sports when they are able to run and pivot without pain while the ankle is braced

- bracing or taping for sports is continued for 6 months after injury




Most return to work by 8/52

20% have pain that limits activity

20 - 40% will have recurrent sprains