2: Joint Disorders Of The Knee Flashcards
How will OA of the knee present
- Functionally-limiting knee pain
- Worse on walking downstairs
- Presents with ‘locking’ sensation of the joint
What causes meniscal tear
rotational injuries
What is a sign of meniscal injury
pain on palpating over the joint line
How will a MCL tear present
‘pop’ at the time of injury
What age group does Osgood-Schlatter disease occur
15-19y
How will Osgood-Schlatter disease present
anterior knee pain
What causes IT band syndrome
repeated flexion and extension of the knee
How will IT band syndrome present
lateral knee pain
How will patellofemoral pain syndrome present
anterior knee pain worse on ascending and descending the stairs
what is OA of the knee
degeneration of articular cartilage
what is the commonest form of OA
knee
in which gender is OA of the knee more common
female
how does the incidence of knee OA vary with age
increases with age
how can the aetiology of knee OA be divided
primary vs. secondary
what is primary knee OA
OA of the knee with no underlying cause
what is secondary knee OA
OA of the knee secondary to an underlying cause
what are 4 causes of secondary knee OA
- Genus valgum
- Genus varum
- Meniscal tears
- Cruciate ligament rupture
what are 5 modifiable risk factors of knee OA
- Occupation (repetitive bending/extension knee)
- Muscle weakness
- trauma
- Obesity
- Metabolic syndrome
what are 3 non-modifiable risk factors of knee OA
- Age
- Female
- Fhx
what are the symptoms of knee OA
- Function-limiting pain
- Worse on walking downstairs
- Locking and catching sensation of the knee
how do you differentiate knee from hip OA
Knee OA is worse on walking downstairs
Hip OA is worse on walking upstairs
what sign is positive in knee OA
Patella apprehension test
briefly explain the pathophysiology of knee OA
‘wear and tear’ causes degeneration of the cartilage. This increases friction between bones resulting in inflammation due to TNFa, IL1 and IL6
What is the criteria to be able to diagnose knee OA clinically
- > 45y
- Activity-related joint pain
- No morning stiffness (or morning stiffness less than 30m)
What investigation may be used in knee OA
X-ray
What are signs of OA on x-ray
Loss of joint space
Osteophytes
Subchondral sclerosis
Subchondral cysts
What is first stage in management of knee OA
Conservative management
What conservative measures can be offered for knee OA (WETT)
Weight loss
Exercise + manual therapy
Thermotherapy
TENS
What is second line for knee OA
Oral Paracetamol or Topical NSAIDs. If ineffective, short-course oral NSAIDs with PPI
What is 3rd line for knee OA
Intra-articular corticosteroids
What is 4th line for knee OA
Surgery
What are the 3 types of surgery that can be offered for knee OA
- High tibial osteotomy
- Unicompartmental knee arthroplasty
- Total knee arthroplasty
What is a high tibial osteotomy
Re-aligns the leg by transferring body weight to unaffected lateral compartment
what are the indications for high-tibial osteotomy
Younger patient with isolated medial compartment unicompartmental disease
what is a unicompartmental knee arthroplasty
The portion of the femur and tibia/fibula in that compartment is replaced
when is a unicompartmental knee arthroplasty indicated
isolated disease to a single compartment
what is a total knee arthroplasty
a cap is placed over the end of the femur and tibia + fibula
what are the indications of total knee arthroplasty (TKA)
symptomatic knee OA
What is a meniscal tear
tear of the lateral and medial meniscus which lie between fibula and tibia (respectively) and the femur
Is the medial or lateral meniscus more frequently torn and why
medial - due to its relative immobility
How are meniscal tears first classified
whether the lateral or medial meniscus is affected
After establishing if they are medial or lateral, how are they classified
location of the tear within the meniscus
What is a ‘white’ tear
tear that occurs in the inner 1/3
Why is the inner 1/3 termed a ‘white tear’
as there is a poor blood supply (it is relatively avascular)
What is a white-red tear
tear in middle 1/3
What is the vascularisation of a white-red tear
poorly vascularised
what is a ‘red’ tear
tear in outer 1/3
what is the vascularisation of the outer 1/3 of the meniscus
highly vascularised
what is the third way to classify meniscal tears
type of tear
what are the two aetiologies of meniscal injury
degenerative or traumatic
in which patients do traumatic meniscal tears occur
younger, active patients
what causes traumatic meniscal tears
rotational injuries with axial loading
what patients does degenerative injury of the menisci occur
older patients
what causes degenerative injury of the menisci
caused by continuous work in a squatting position
how will meniscal injury present
- Pain on weight bearing
- Delayed knee effusion
what movement will be limited in meniscal injury
Extension of the knee
what is a sign of meniscal injury
Tenderness over the medial or lateral joint line
what may a meniscus cause if it obstructs knee movement
‘locking’ sensation of the knee
if the ‘red zone’ of the meniscus is injured what type of knee effusion is It
Haemoarthrosis
If the ‘white zone’ of the meniscus is injured what type of knee effusion is it
Serous effusion
What are two tests for meniscal injuries
- Appley’s
2. Mcmurray’s
what its he unhappy triad
Pattern of injury that occurs on lateral ‘blow’ to the knee
what is injured in the unhappy triad
- Meniscal tear
- MCL tear
- ACL tear
explain why the medial meniscus is more commonly injured
The medial meniscus is ‘half-moon’ shaped. It is immobile and attached to the MCL. It is therefore not protected from shearing forces on internal rotation.
explain why the lateral meniscus is not commonly indicated
Lateral meniscus is mobile, it easily dissipates sharing forces. It is protected during internal rotation by the cruciate ligament
what is first-line investigation of meniscal tear
MRI
if MRI is contraindicated, what investigation may be performed
Arthroscopy
what is first-line management of meniscal tear
Conservative: ‘P.OL.I.C.E’ and NSAIDs
what is surgical management of meniscal tears
Arthroscopy
when is arthroscopy for meniscal injury indicated
- Persistent disabling symptoms
- Functional limitation
- Complex tears
what are 2 complications of meniscal tears
Secondary OA
Baker’s cysts
What causes MCL ligament sprain
Excessive valgus stress
What is the most common ligamentous injury
MCL sprain
In which gender is MCL sprain more common
Females
What are 3 causes MCL sprain
- Ski-ing with valgus stress
- Lateral blow to the knee from contact sports
- excessive valgus stress (often with slight flexion and external rotation)
what is a RF for MCL injury
Althetes
How will MCL injury present clinically
‘popping’ sensation, followed by knee swelling and ecchymosis
Which injury is MCL sprain often associated with
tear of medial meniscus
What are 3 signs of MCL sprain
- pain on palpating over medial joint line
- increased medial joint laxity
- positive valgus stress test
What is the unhappy triad
series of injures caused by traumatic lateral blow to the knee
what injuries comprise the unhappy triad
MCL tear
ACL tear
Medial Meniscus tear
what is the physiological action of the MCL
Prevents excessive valgus stress
how are suspected MCL sprains investigated
MRI
how is the severity of MCL injuries assessed
‘Grading’
what is a grade I MCL tear
Small tears and stress of MCL
what is grade II MCL tears
Larger, but incomplete tear
what is grade III MCL tears
Complete tears
what is first-line management for grade I MCL tears
NSAIDs
what is first-line management for grade 2 and 3 MCL tears
NSAIDs and Bracing
what is second-line management for MCL tears
Surgery
what are the two types of MCL surgery
- Ligament repair
2. Ligament reconstruction
what are the indications for ligament repair
- Multiple ligamentous injury
- Instability despite conservative management
what are the indications for ligament reconstruction
- Chronic injury
- Insufficient tissue for repair
What is osgood schlatter’s disease also referred to as
tibial apophysitis
what causes osgood schalatter’s disease
over-use of the quadriceps muscle during periods of growth causing traction apophysitis of the patella tendon on its insertion of the tibial tuberosity.
which age-group does osgood schlatter’s disease tend to occur
9-15y
in which gender is osgood schlatters (tibial apophysitis) more likely to occur
male (3:1)
what causes osgood schlatter’s disease
over-use of quadriceps tendon by running and jumping activities during ossification period (adolescence)
how will osgood schlatter’s disease present clinically
- anterior knee pain worse on activity
- proximal tibial swelling
how can pain of osgood schlatter’s disease be reproduced in a clinical setting
- pain will be reproduced on extension against resistance
what type of structure is the tibial tuberosity
apophysis
what is an apophysis
bony structure where tendon inserts
what attaches to the tibial apophysis
patella ligament
explain development of the tibial tuberosity
the tibial epiphysis consists of cartilage, with a primary ossification centre inside. It starts to ossify at 9-15y, forming tuberosity at 18y.
why does tibial apophysitis occur between 9-15y
During 9-15y the tibial tuberosity has not ossified yet and hence is too weak to resist traction from the patella ligament (on repetitive movement) causing traction apophysitis
how can osgood schlatter’s disease be diagnosed
USS
how is osgood schlatter’s disease treated
Conservative - Ice, reduced physical activity, strengthening and stretching of the quadriceps
what is the prognosis of osgood schlatter’s disease
Often resolves when bone maturity is reached
Where does the IT band attach
Lateral femoral condyle
What is IT band syndrome
Inflammation of the IT (illio-tibial) band caused by friction against lateral femoral condyle
What is the epidemiology of IT band syndrome
Common injury. Most common in endurance athletes
What causes IT band syndrome
Repetitive flexion and extension of the knee (eg. cycling, running)
How will IT band syndrome present
- Sharp pain in lateral knee when the foot strikes the ground
- Dull ache at rest
What test can be used for IT band syndrome
Noble’s test
Explain Noble’s test
Patient lies on their side. Examiner flexes the leg with thumb over the lateral femoral condyle. Positive if pain is elicited
Explain the pathophysiology of IT band syndrome
Over-use injury due to repetitive flexion and extension of the IT band. Thought to occur due to underlying weakness in the abductors.
What is the IT band
Thickened band of fascia that is comprised of fibrous tissue from the tensor fascia lata and gluteus maximus. It projects from lateral thigh and inserts onto portion of tibial plateau termed Gerdy’s tubercle
How is IT band syndrome diagnosed
Clinically (/diagnosis of exclusion)
How is IT band syndrome managed
Conservative - rest, NSAIDs, physiotherapy
What is the prognosis of IT band syndrome
40-80% of cases resolve in 4-8W
What is patellofemoral pain syndrome
generalised knee pain over the patella or surrounding area
What causes patellofemoral pain syndrome
- trauma
- muscle weakness
- malorientation of the patella
How does patellofemoral pain syndrome present
Anterior knee pain worse on ascending and descending the stairs
Which structure is most likely to be damaged during a total knee arthroplasty
The common peroneal nerve
