Derbyshire Sports Injuries Clinic presents
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Transcript Derbyshire Sports Injuries Clinic presents
The Knee
Anatomy- 1st layer
The knee joint
Made up of two
joints:
Tibiofemoral joint:
Hinge joint
Collateral ligaments
Cruciate ligaments
Menisci
Patellofemoral joint:
Medial retinaculum
Patellar tendon
Anatomy-ligaments
ACL
PCL
MCL
LCL
Popliteal ligaments
Meniscofemoral
ligament
Transverse ligament
Anatomy-medial view
Anatomy- lateral view
Anatomy-posterior view
Anatomy- bursae
Movements of the knee
Flexion
Extension
Accessory movements in certain positions can
take place with external forces:
Valgus
Varus
External rotation
Internal rotation
Patient walks in c/o knee pain
What is the mechanism of
injury?
A planted foot with a valgus
force and/ or twisting
movement is a serious position
of danger for the knee
Was there a noise?
Did the knee swell up
immediately?
Is there any bruising?
Was the patient able to play
on?
Is the patient able to
weightbear?
Is there any clicking/ giving
way/ locking now?
Patient walks in c/o knee pain
Acute, chronic or sub-acute?
Does pain increase or decrease with activity?
Patient’s job and leisure activities and any
possible contributing factors?
Gait? Limping or normal walking? Able to cope
with stairs?
Does the patient have any hip pain?
Any back pain? Leg pain? Could this be an L3
Nerve root compression?
Where is the pain?
Causes of haemarthrosis
ACL tear
PCL tear
Patella dislocation
Osteochondral fracture
Peripheral tear of the meniscus (more
commonly medial)
Hoffa’s syndrome (acute fat pad
impingement)
More clinical pearls
There is little effusion with collateral ligament
tears
An effusion that develops after a few hours or the
next day is a feature of meniscal and chondral
injuries
Assume everything with a pop or a snap is an ACL
tear
Assume all clicking and locking is meniscal...
Especially loss of extension
If the knee locks in extension and flexion is
difficult it is likely to be patellofemoral pain
Giving way can be indicative of ACL or meniscal
injury, but if this is longstanding with no injury, it
may be muscle weakness
Ottawa Knee rules
Age 55> or <18
Tenderness at head of
fibula
Isolated patella
tenderness
Inability to flex to 90°
Inability to bear weight
both immediately and in
the emergency
department (4 steps)
High suspicion are:
High speed injuries
Children or adolescents
Clinical suspicion of loose
bodies
90% of knee X-rays are normal.
Assessment
Observe active range:
ability to squat if
appropriate, control
through the knee.
Observe position of
patella in standing
Passive range of
movement in supine:
loss of particularly
extension will cause
long term problems
Palpate the patella for
differences from side
to side
ACL assessment
Anterior Drawer test:
Knee at 90° flexion, foot kept stable
Tibia drawn anteriorly
Assess for degree of movement and end point
Lachman’s Test
Knee at 15° flexion
Draw tibia forward
Assess for degree of movement and end point
ACL assessment
Pivot Shift Test:
Tibia internally rotated
Knee in full extension
Apply a valgus force
In a knee with ACL deficiency the condyles will sublux.
The knee is then flexed, looking for the clunk of a
reduction, a positive Pivot shift. Extending the knee
again, if the knee clicks, this is a positive ‘jerk test’.
Loss of ROM, especially extension
Lateral joint line tenderness due to lateral joint
capsule stretching due to subluxation
Medial joint line tenderness if associated meniscal
injury
ACL injury
Relatively common in sport
Over 10 000 ACL reconstructions performed in
the USA every year
Generally sports that involve pivoting...
Football, netball, rugby, gymnastics, downhill
skiing etc.
2-10 x higher risk in females
Can occur in isolation or with meniscal,
articular cartilage and MCL injury
ACL injury
75% rupture chance if there was a twist, a pop and a
click!
Extremely painful, particularly at first
Athletes are initially unable to continue their activity,
and further activity is limited by significant
haemarthrosis. Very occasionally this can be delayed.
Some athletes ‘try’ to play again when knee has
settled and report incidences of acute instability
Examination of the knee when swollen is very difficult.
Diagnosis should be based on subjective report, and
appropriate referral made.
MRI is the imaging of choice, but X-ray is needed to
check for an avulsion fracture (‘Segond’).
80% of ACL tears have a bone bruise over the lateral
femoral condyle.
PCL assessment
Posterior sag:
Both knees flexed to 90° and patient relaxed
Observe tibia position relative to femur
Reverse Lachman’s Test
Lachman’s prone!
Posterior drawer test
Knee at 90°, push tibia posteriorly
Also assess in internal and external rotation
Assess range and quality of end point
X-ray to ensure no bony avulsion
MRI is the gold standard for PCL tear
assessment
PCL injury
PCL is a primary restraint to posterior drawer
and secondary restraint to external rotation.
Less common than ACL (thicker ligament),
usually associated with meniscal and chondral
injury as well as lateral meniscus injury.
Usually results from a blow to the anterior
tibia with the knee flexed.
Hyperextension may also result in injury to
the PCL and posterior capsule.
Pain is poorly defined, posterior pain,
sometimes in the calf.
Collaterals
MCL: Valgus force
LCL: Varus force
Test at full extension and also 30° flexion
Grade 1: hurts on testing with no laxity visible
Grade 2: hurts and gaps with laxity but with end
point
Grade 3 isn’t that painful on testing, LARGE
amount of movement. Feels ‘wobbly’. Frequently
associated with ACL injuries, often capsular
tearing with this grade, swelling therefore present
Always local tenderness at insertion point
Collateral ligament injury
MCL is a result of a
valgus force
LCL tear is less
common and due to a
high-energy direct
varus stress on the
knee and often
associated with PCL
tear
Treatment is generally
conservative, although
bracing is required for
more severe injuries.
Menisci
Pain on palpation of the joint line
Positive McMurray’s test:
The knee is flexed and at various stages of
flexion the tibia is internally and externally
rotated
Pain and a ‘clunk’ make this test positive
Joint effusion
Pain on squatting (especially if posterior horn is
involved)
Restricted ROM
MRI is investigation of choice
Meniscal injury
Generally a twisting injury
Doesn’t have to be a quick injury
Degree of pain associated with an acute injury can
vary dramatically.
Sometimes a tearing sensation will be felt
Sometimes pain is of late onset... Up to 24 hours later
Small tears may also occur with minimal trauma in the
older athlete as a result of degenerative changes
Surgical indications include:
Inability to continue playing
Locked knee or severe lack of ROM, particularly EOR
flexion
Palpable clunk on McMurray’s Test
Associated ACL tear
No change after 3 weeks post-injury
Patella and tendon
Assess the patella in 30° knee flexion, push
the patella laterally, if the patient has
apprehension, consider a dislocating patella
Pain infrapatella is usually the tendon (or can
be bursal)
Fractured patella can occur due to direct
trauma or through quadriceps avulsion.
In adolescents consider Osgood Schlatter’s
Disease, particularly if a prominent tibial
tubercle. This is a growth plate
osteochondritis
Articular cartilage damage
Chondral damage can
be a major cause of
symptoms in the knee
Can be primary or
secondary
(ligamentous
instability... ACL has
high incidence of
medial & lateral
femoral condyle and
tibial plateau chondral
damage)
Anterior knee pain
20-40% of all MSK
consultations in general
practice
Generally AKP is due to:
Patellofemoral pain
Patella tendinopathy
Other causes can include:
Synovial plica
Pre-patella/ infrapatella
bursitis
Fat pad impingement
Quadriceps tendinopathy
Patellofemoral instability
Patellofemoral pain
Generally insidious onset, vague pain
Often secondary to an acute incidence
A diffuse ache exacerbated by loading eg stairs or
running... Doesnt tend to have to be eccentric loading
only.
Prolonged sitting can be painful
Worsening pain while exercising tends to be PFPS,
while pain at start of exercise, and ceasing of exercise
tends to be Patella tendinopathy
Previous injury to the knee predisposes one to PFPS
Any effusion around the knee >15ml of fluid will
switch off VMO (major stabiliser of the knee)
increasing the risk of adverse knee mechanics and
therefore PFPS
Assess the patella position relative to the painfree side
Patella tendinopathy
Mostly involves jumping/ multidirectional sports
Significantly more painful with eccentric loading
rather than any other type of loading
Pain is inferior pole of the patella, or the tendon
Pain is always bad in the morning
Chronic tendinopathy can take 3-6 months to
settle
Surgery is only indicated after a considered and
lengthy conservative programme has failed
Lateral knee pain
Mostly due to Ilitobial band
friction syndrome (ITBFS)
Repeated flexion/ extension at
the knee causes ITB to rub on
the lateral epicondyle
Training errors and
biomechanical problems are the
major causes of ITBFS
Occasionally biceps femoris
tendon can become inflamed and
tender
Superior tib-fib joint can also
give lateral knee pain
OA of the lateral compartment
Nerve root irritation/ entrapment
Medial knee pain
PFPS
Medial meniscal
injury
OA of the medial
compartment
Pes anserinus
bursitis
Referred pain
Posterior knee pain
Biceps femoris,
gastrocnemius or
popliteus
tendinopathy
Referred pain
Baker’s cyst
Posterolateral corner
injury
DVT
Claudication
Advice to you as GPs
If it’s swollen, refer to orthopaedics
If it’s anterior knee pain, always refer to physio
If it’s giving way, refer to orthopaedics
A painless click is not a problem, as long as no
locking or giving way is associated.
Kids with Osgood’s should rest when sore, and try
to get strong when condition is stable
Rest will NEVER fix an injury.
Cycling (not standing on the pedals) is generally a
knee friendly sport. Running is not.