PPT on Ligamentous and meniscal injuries around knee joint

1. Ligamentous Injuries
Around the Knee
Dr. VINAY PAWAR
Department of Orthopaedics
KIMS, Hubli

2. RELEVANT ANATOMY
• The knee is a hinge joint formed between the tibia and femur(tibio-femoral)
• The patella glides over the front of femoral condyles to form a patellofemoral
joint.
• The stability of the knee depends primarily upon its ligaments

4. Extensor apparatus of the knee:
• It is constituted from proximal to distal, by quadriceps muscle, quadriceps tendon, patella with
patellar retinaculae on the sides, and the patellar tendon.
• Failure of any of these results in inability to actively extend the knee, called extensor lag

6. MECHANISM OF KNEE INJURIES
The nature of the forces may be direct or indirect.
• An indirect force on the knee may be:
• (i) valgus; (ii) varus; (iii) hyperextension (iv) twisting
• Most often it is a combination of the above forces.

7. MECHANISM
• Medial collateral ligament: This ligament is damaged if the injuring force has the effect of
abducting the leg on the femur (valgus force). It ruptures most commonly from its femoral
attachment.
• Lateral collateral ligament: This ligament is damaged by a mechanism just the reverse of above i.e.,
adduction of the tibia on the femur (varus force). Commonly, the ligament is avulsed from head of the
fibula with a piece of bone. Lateral collateral ligament injuries are uncommon because the knee
is not often subjected to varus force (the knee is not likely to be hit from the inside).

8. • Posterior cruciate ligament: This ligament is damaged if the anterior aspect of the
tibia is struck with the knee semi-flexed so as to force the tibia backwards on to the
femur.
• Anterior cruciate ligament: This ligament is most commonly ruptured, often in
association with the tears of medial or lateral collateral ligaments. Commonly, it occurs
as a result of twisting force on a semi-flexed knee.
• Often the injury to medial collateral ligament, medial meniscus and anterior cruciate
ligament occur together. This is called O'Donoghue triad.

9. • The ligament may tear at either of its attachment. Sometimes, it takes a chip of bone
from its attachment.
• The ligament may be torn in its substance (mid-substance tear).
• The severity of the tear varies from a rupture of just a few fibres to a complete tear .
• It may be an 'isolated' ligament injury, or more than one ligaments may be injured.
• Rarely, in a very severe injury, the knee may get dislocated and a number of ligaments
injured.
PATHOANATOMY

10. DIAGNOSIS
Clinical examination:
• Pain and swelling of the knee are the usual complaints.
• Often, the patient is able to give a history of having sustained a particular type
of deforming force at the knee (valgus, varus etc.), followed by a sound of
something tearing.
• Swelling (haemarthrosis) is variable, but appears early after the injury

11. 1. Anterior drawer test: This is a test to detect injury to the anterior
cruciate ligament.
2. Lachmann test. A similar test in which anterior glide of the tibia is
judged with the knee in 10-15 degrees of flexion.
3. Posterior drawer test: This is a test to detect injury to the posterior
cruciate ligament. A posterior sagging of the upper tibia may be
obvious, and indicates a posterior cruciate tear.

14. Radiological examination:
• A plain X-ray may be normal, or a chip of bone avulsed from the
ligament attachment may be visible.
• It may be possible to demonstrate an abnormal opening-up of the joint on
stress X-rays.
• MRI is a non-invasive method of diagnosing ligament injuries, and may be
of use in doubtful cases
• Arthroscopic examination may be needed in cases where doubt persists.

17. TREATMENT
Conservative method:
• The haematoma is aspirated and the knee is immobilised in a cylinder cast or
commercially available knee immobiliser.
• Most cases of grade I and II injuries can be successfully treated by this
method. After a few weeks, the swelling subsides, and adequate strength
can be regained by physiotherapy.

19. Operative methods:
These are indicated in multiple ligament injured knee, especially in young
atheletes. It consists of the following:
a) Repair of the ligament: It is performed for fresh, grade III collateral ligament
injuries. In cases presenting after 2-3 weeks, an additional reinforcement
is provided by a fascial or tendon graft.
b) Reconstruction: This is done in cases of ligament injuries presenting late with
features of knee instability. A ligament is ‘constructed’ using patient's
tendon or fascia lata. A tendon or fascia taken from another person
(allograft) or a synthetic ligament has also been used.

20. COMPLICATIONS
1. Knee instability: An unhealed ligament leads to instability. The patient 'loses
confidence' on his knee, and the knee often "gives-way". Surgery is usually required.
2. Osteoarthritis: A neglected ligament injury may result in further damage to the
knee in the form of meniscus tear, chondral damage etc. This eventually leads to knee
osteoarthritis.

21. MENISCAL INJURIES OF THE KNEE

23. • The injury is sustained when a person, standing on a semi-flexed knee, twists his body
to one side.
• The twisting movement, an important component of the mechanism of injury, is
possible only with a flexed knee.
• During this movement the meniscus is 'sucked in' and nipped as rotation occurs between
the condyles of femur and tibia. This results in a longitudinal tear of the meniscus.
• A degenerated meniscus in the elderly may get torn by minimal or no injury.
• The medial meniscus gets torn more often because it is less mobile (being fixed to the
medial collateral ligament).
MECHANISM

24. PATHOANATOMY
• The meniscus is torn most commonly at its posterior horn. With every subsequent
injury, the tear extends anteriorly.
• The meniscus, being an avascular structure, once torn does not heal.
• If left untreated, it undergoes many more subtears, and damages the articular cartilage,
thus initiating the process of osteoarthritis.

26. CLINICAL FEATURES
Presenting complaints:
• The patient is generally a young male actively engaged in sports like football, volleyball etc.
• The presenting complaint is recurrent episodes of pain, and locking of the knee.
• This may be followed by a swelling.
• On tracing back the symptoms to their origin, one often finds a history of a classic
twisting injury to the knee, followed by a swelling appearing overnight (The swelling in a
case of meniscus tear is due to synovial reaction, hence appears after a few hours)
• The history of sudden locking and unlocking, with a click located in one or other joint
compartment, is diagnostic of a meniscus tear.

27. On examination:
• The knee may be swollen.
• There may be tenderness in the region of the joint line, either anteriorly or posteriorly.
•
• The knee may be locked
• Gentle attempts to force full extension produces a sensation of elastic resistance and
pain, localised to the appropriate joint compartment.
• The mano euvres carried out to detect a hidden meniscus tear are McMurray's and
Apley's test

28. Often it is difficult to diagnose the cause of knee symptoms on
history and clinical examination. Such non-specific symptom-
complex is termed as internal derangement of the knee (IDK).

29. RADIOLOGICAL EXAMINATION
• With meniscal tears there are no abnormal X-ray findings.
• X-rays are taken to rule out any associated bony pathology.
• MRI is a non-invasive method of detecting meniscus tears.
• It is a very sensitive investigation, and sometimes picks up tears which are of no clinical
significance.

30. • Arthrography: It is a technique where X-rays are taken after injecting radiopaque dye
into the knee. The dye outlines the menisci, so that a tear, if present, can be
visualised. Being an invasive technique, it is no longer used.

31. ARTHROSCOPY This is a technique where a thin endoscope, about 4-5 mm in
diameter – the arthroscope, is introduced into the joint through a small stab
wound, and inside of the joint examined.

32. Treatment of acute meniscal tear:
• If the knee is locked, it is manipulated under general anaesthesia. No special manoeuvre
is needed. As the knee relaxes, the torn meniscus falls into place and the knee is
unlocked.
• In a case where locking is not present, immobilisation in a knee immobiliser is sufficient.
• With this, a small number of peripheral tears will heal.

33. Treatment of a chronic meniscal tear:
• The treatment is to excise the displaced fragment of the meniscus.
• Now-a-days, it is possible to excise a torn meniscus arthroscopically (arthroscopic
surgery)
• Recent research has shown that menisci are not ‘useless’ structures as was
thought earlier.
• Hence, wherever possible the trend is to preserve the meniscus by suturing. The state-
of-the-art is arthroscopic meniscus suturing.

36. THANK YOU