This presentation is about anatomy of ankle, classification of ankle injuries, the clinical features with which patient will present, the examination and treatment of them and the complications associated.
3. ANATOMY
■ The ankle joint is a modified hinge joint.
■ The ‘Socket’ is formed by the distal
articular surfaces of tibia and fibula, the
intervening tibio-fibular ligament and the
articular surfaces of the malleoli.
■ These together constitute the ‘ANKLE-
MORTISE’
■ The superior articular surface of the talus
articulates with this socket.
■ The strong tibio-fibular syndesmosis,
along with the medial and lateral malleoli
make the ankle a strong and stable
articulation.
4. LIGAMENTS
■ The ankle joint has two main ligaments
■ Medial Collateral ligament (Deltoid Ligament)
:-
Tibio-calcaneal (superficial)
Tibio-talar (deep)
■ Lateral Collateral ligament :- weak ligament
and often injured
Anterior talo-fibular
Calcaneo-fibular
Posterior talo-fibular
5. DIFFERENT FORCES THE ANKLE
MAYBE SUBJECTED TO
■ INVERSION
■ EVERSION
■ SUPINATION
■ PRONATION
■ ROTATION( External or
Internal)
■ VERTICAL COMPRESSION
6. CLASSIFICATION
■ The Lauge-Hansen classification of ankle injuries is most widely used. It is
based on the mechanism of injury.
■ It is believed that a specific pattern of bending and twisting forces results in
specific fracture pattern
■ Different types of ankle injuries have been classified on the basis of whether the
foot was supinated or pronated at the time of injury, and what forces was it
subjected to in that position.
■ Following combination are present :-
Suppination-adduction injuries
Pronation-abduction injuries
Pronation-external rotation injuries
Supination-external rotation injuries
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8. Supination-adduction injuries
■ An adduction force with the foot in plantar-flexion results
in a sprain of the lateral ligament of the ankle.
■ It may be either a partial or complete rupture.
■ A partial rupture is limited to the anterior fasciculus of
the lateral ligament . In a complete rupture, the tear
extends backwards to involve the whole of the lateral
ligament complex. As complete rupture occurs, the talus
tends to subluxate out of the ankle-mortise.
■ The inversion force on an ankle in neutral or dorsiflexed
position results in an avulsion fracture of lateral
malleolus to begin with, usually transverse and below
the joint line. A more severe force results in additional
fracture of the medial malleolus.
■ Typicaly, a fracture with the fracture line running
obliquely upwards from the medial angle of the ankle.
9. Pronation-abduction Injuries
■ In this type, the medial structures are
subjected to a distracting force and the lateral
structures to compressive force.
■ This results in rupture of the deltoid ligament
or a low-lying transverse tracture of the
medial malleolus on the medial side. On the
lateral side, a fracture of the lateral malleolus
at the level of the ankle-mortise or more
proximal level with comminution of the outer
cortex occurs .
■ The talus, with both malleoli fractured,
subluxates laterally. This commonly
produces bimalleolar fracture.
10. Pronation-external rotation injuries
■ When a pronated foot rotates externally, the talus
also rotates outwards along its vertical axis. The
first structures to give way are those on the
medial side. There may occur a transverse
fracture of the medial malleolus at the level of the
ankle-mortise, or a rupture of the medial collateral
ligament.With further rotation of the talus, the
anterior tibio-fibular ligament is torn.
■ This is followed by a spiral fracture of the lower
end of the fibula. This fracture occurs above the
level of ankle joint, and indirectly indicates injury
to tibio-fibular syndesmosis.
■ Occasionally, the fibular fracture may occur as
high as the neck of the fibula (Maisonneuve's
fracture).The continuing rotational force may
further tear the posterior tibio-fibular ligament or
may cause fracture of posterior malleolus. This
makes it trimalleolar fracture*.
11. Supination-external rotation injuries
■ With the foot supinated, the talus twists externally
within the mortise. As the medial structures are lax,
the first structure to give way is that on the lateral
side, the head of the talus striking against the lateral
malleolus, producing a spiral fracture at the level of
the ankle-mortise.
■ The next structure to break is the posterior malleolus.
As the talus rotates further, it hits against the medial
malleolus resulting in a transverse fracture .
■ The tibio-fibular syndesmosis may remain intact or
get torn depending upon level of fracture of fibula. In
extreme cases, the whole foot along with three
malleoli, is displaced.
12. Tibial-pilon fracture
■ This fracture at the ankle Acura as a result of
primarily axial compression force, whereby the
dome of talus hit the distal articular surface of tibia.
■ It’s results in variable comminuted fracture of the
distal articular surface with or without a fracture of
fibula.
■ This type of fracture is often associated with
severe injury to skin and soft tissue around ankle.
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16. Clinical Features
■ There is history of a twisting injury to the ankle followed by pain and swelling.
■ Often patient is able to describe exactly the way the ankle got twisted.
■ Swelling and tenderness may be localised to injury site.
■ Crepitus may be noticed if there is a fracture .
■ The ankle may be lying deformed( adducted or abducted , with or without
rotation)
17. Radiological Examination
■ Antero-posterior and lateral X-rays of the ankle are sufficient in most cases.
■ While examine X-ray, it is important to make note of the following features:-
Fracture Line: of medial and lateral malleoli should be studied in order to evaluate the
type of ankle injury. Small avulsion fractures from the malleoli are sometimes missed .
Tibio-fibular syndesmosis: All ankle injuries where the fibukar fracture is about the
mortise, the syndesmosis is bound for have been disrupted. In injuries where the fibular
fracture is at the level of the syndesmosis, one must carefully look for any lateral
subluxation of the talus.
Posterior Subluxation of the talus should be looked for , on the lateral X-ray.
Soft tissue swelling on the medial or lateral side in absence of a fracture must arouse
suspicion of a ligament injury.
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20. TREATMENT
■ Principle of Treatment
The complexity of the forces involved produce a variety of combinations of
fractures and fracture dislocations around the ankle. The basic principle of
treatment is to achieve anatomical reconstruction of the ankle-mortise.
This helps in restoring good function and reducing the possibility of late onset
osteoarthritis of ankle.
In some undisplaced fractures there is a role of conservative methods. In
most, an operative reduction and internal fixation is required.
21. ■ Fractures without displacement : It’s is usually sufficient to protect the ankle in a
below knee plaster for 3-6 weeks.
■ Conservative methods:- It is often possible to achieve a good reduction by
manipulation under general anaesthesia. The essential feature of the reduction
is to concentrate on restoring the alignment of the foot to the leg. By doing so
the fragments automatically fall into place. Once reduced, a below-knee plaster
cast is applied. If the check X-ray shows a satisfactory position, the plaster cast
is continued for 8-10 weeks.The patient is not allowed to bear any weight on the
leg during this period. Check X-rays are taken frequently to make sure the
fracture does not get displaced. It everything goes well, the plaster is removed
after 8-10 weeks. Physiotherapy is begun thereafter to regain movement at the
ankle.
22. ■ Fractures with displacement :-
Operative methods :-
■ INTERNAL FIXATION:- In general, operative reduction and internal fixation may be
used in cases where closed reduction has not been successful, or the reduction has
slipped during the course of conservative treatment. The following techniques of
internal fixation are used depending upon the type of fracture.
Medial Malleolus Fracture :-
■ Transverse fracture – compression screw, tension-band wiring
■ Oblique fracture – compression screw
■ Avulsion fracture – tension-band wiring
Lateral Malleolus Fracture:–
■ Transverse fracture – tension-band wiring
■ Spiral fracture – compression screws
■ Comminuted fracture- buttress plating
■ Fracture of the lower third of fibula – 4 – hole plate
■ EXTERNAL FIXATION:- This may be required in case where closed methods cannot
be used eg open fractures with bad crushing of muscles and tendons, with skin loss
around the ankle.
