The Knee Flashcards
What red flags to look out for when assessing the knee?
Osteosarcoma
Loosening/infection of knee arthroplasty
Acute locked knee
Spontaneous Osteonecrosis of the knee
Popliteal aneurysm
Red flag: Osteosarcoma (S+S)
- Bone pain/pain around joint
- Constant or more severity at night
- Swelling/mass/deformity
- Stiffness
- Fatigue
Red flag: Loosening/infection of the Knee arthroplasty
- Red, hot swollen joint/wound
- Feeling generally unwell- fever, chills, night sweats
- Pus/fluid from incision
- Signs of sepsis
- Fatigue
- New onset of knee pain/stiffness
- Feeling of instability
Red flag: Acute Locked Knee (S+S)
- History of trauma/injury
- Knee blocked to full extension
- Effusion
- Joint line tenderness
Red flag: Spontaneous Osteonecrosis of the knee
- Sudden onset of severe knee pain
- Effusion
- Loss of ROM
- Most commonly affects medial condyle
- Tenderness along joint line
- Pain at night and on weight bearing
Red flag: Popliteal Aneurysm (S+S)
- Pulsatile mass in the back of the knee
- Pale
- Pain
- Pallor
- Paraesthesia
- Pedal pulses - reduced/absent
- Blue toes
OA of the knee: pathophysiology and risk factors
The most common knee pathology to affect the older pop
Females are most likely affected
- A pathology which occurs as a result of a multiple factors which lead to synovial joint degradation.
Can be idiopathic or secondary
Risks:
- Age
- Obesity
- Gender
- Repetitive stress
Signs and symptoms of OA of the knee
- Global anterior pain as well as joint line pain
- Early morning stiffness or after prolonged rest which resolves within 30 mins
- Swelling
- Crepitus
- Restriction to flexion and extension with or without pain
- Aggr: walking, squatting, stairs, bending
Management of knee OA
- Education, self and symptom management
- Advise of lifestyle modifications
- Direct to GP
- Physio: manual therapy, mobility, strengthening, proprioception
- CSI
No improvement: surgery
Patellofemoral Pain Syndrome (PFPS): pathophysiology
Umbrella term that is used to describe conditions that cause pain from the patellofemoral joint.
Unclear underlying pathology but theories: malalignment, increased Q-angle, tightness of hip and thigh, patella alta
Risk factors for Knee pain
- Increased age
- Overweight
- Social deprivation
- Hx of injury
- Participation in sport involving high impact
- Knee straining work
Signs and symptoms of Patellafemoral pain syndrome
- Worsens with activity which increase load on the patellofemoral joint (squatting, sitting, climbing stairs, kneeling and running)
- Anterior pain ‘underside of patella’
- Feeling of giving way and crepitus
On examination: - Abnormal patella positions
- Occasional swelling
- AROM is usually maintained but can be stiff
What are the grades for ligamentous injuries?
Grade 1= damage to only a minimal number of ligamentous fibres.
Which can produce local tenderness but no instability or laxity apparent within the ligament
Grade 2= partial tears. More ligamentous fibres are damaged than in grade 1.
These tears causing slight to moderate loss of normal motion in the ligament
Grade 3= complete tear or rupture of the ligament.
Significant disruption of the fibres causing a noticeable instability at the joint
ACL injury: pathophysiology and mechanism
Injury to the ACL which is responsible for preventing anterior translation of the tibia on the femur and preventing hyperextension
Common mechanism: sudden deceleration combined with a change of direction in a fixed foot position
Mention grades of ligament injury
Signs and symptoms of ACL injury
- Patients describe a sudden, painful popping sensation which is followed by a significant rapid onset of swelling
-ACL injuries can occur with interal injuries e.g medial meniscal and medial collateral ligament injury- ‘unhappy triad’
-Describe ‘giving way
On examination: - Significant swelling if recent
- Knee AROM can be restricted but not always
- Tenderness apparent on lateral knee with some joint line tenderness
- Muscle weakness in lower limb
Special tests/objective signs for ACL injury
- Lachman’s
- Anterior draw
- Poor single leg balance
PCL injury: Pathophysiology and mechanism
Injury to the PCL which is responsible for preventing posterior translation of the tibia on femur
Common mechanism: A direct blow to the anterior tibia with the knee in a flexed position
Signs and symptoms of PCL injury
-Descriptions of posterior knee pain particularly when kneeling (however can describe anterior knee pain)
-Giving way or instability within the knee joint
-Can occur with other internal injuries such as ACL ruptures and injuries to the posterolateral corner of the knee complex (ligaments and tendons at the posterior and lateral part of knee)
On examination:
- Some swelling if recent or no swelling at all
-Knee AROM can be restricted but not always
The majority of patients will maintain full ROM
Special tests/objective signs for PCL injury
-Posterior drawer test often positive along with positive posterior sag sign
- Poor single leg stance
MCL injury: pathophysiology and mechanism
Injury to the MCL which prevents valgus movement of the tibia on the femur
Mechanism of injury: direct blow to the lateral aspect of the knee joint or during valgus knee twisting
Signs and symptoms of MCL injury
- Patients commonly describe medial knee pain particularly when twisting or during movements that cause valgus knee position
-Can occur in isolation or with other internal knee injuries such as ACL ruptures and medial meniscal injuries as part of the ‘unhappy triad’
On examination: - Swelling or no swelling
- Knee AROM can be restricted
The majority of patients will maintain the full range of motion - Tenderness along the MCL itself
Special tests/objective signs of MCL injury
- Positive during MCL stress (valgus stress) test with pain and/or laxity reproduced
- Muscle weakness in lower limbs
LCL injury: Pathophysiology and mechanism
Injury to the LCL which prevents varus of the tibia on the femur
Common mechanism: direct blow to the medial aspect of the knee joint or during varus knee twisting injury
Signs and symptoms of LCL injury
- Less common than MCL
- Lateral knee pain particularly when twisting or during movement that cause varus knee position
- May occur in isolation or with other internal injuries and damage to the peroneal nerve
Special tests/objective signs of LCL injury
- Positive test during LCL (or varus stress) test with pain and/or laxity
- Muscle weakness in lower limbs
Meniscal injury or degenerative tears: Pathophysiology and mechanism
Injury to either menisci (lateral or medial) which shock absorb and efficient forload transfer
Signs and symptoms of a meniscal injury or degenerative tear
-Degenerative tear can occur with no mechanism of injury or trauma reported
-Pain on the associated joint line
-Locking, catching or giving way
-Joint line pain during twisting movements
-May occur in isolation or in combination e.g ACL injury
On examination:
- Swelling commonly seen but doesn’t have to be apparent
- Knee AROM can be restricted but not always
- There may be a blocked apparent into extension or flexion
Special tests/objective signs of a meniscal injury or degeneration tear
- Positive mcMurrays test with pain or clicking produced
- Muscle weakness in lower limbs
Patella dislocation: Pathophysiology and mechanism
Can be atraumatic or traumatic
Most common mechanism of injury is seen through a direct blow to the patella causing the patella to leave contact with the femur
Signs and symptoms of Patella dislocation
On examination:
- Out of place patella (laying out of the joint either more medially or laterally)
- Swelling
- Tenderness on palpation of the patella
- Significant reduced ROM
- Following relocation range and strength may still be reduced
Quadriceps tendon or patella tendon rupture: pathophysiology and mechanism
One of the most serious injuries surrounding the knee
Mostly affects males
Quad rupture- over 45, patella tendon rupture- under 45
The rupture to the quadriceps tendon (superior patella insertion) or patella tendon (inferior insertion)
Common mechanism: during sport or following a fall. Or spontaneous rupture (long-term steriod use)
Signs and symptoms of Quadriceps tendon or patella tendon rupture
- Describe a pop or snap with an associated anterior knee pain
- Describe struggling to walk or lock, reporting giving way
- Palpable gap in the quads or patella tendon
- Change in height of where the patella rests
- Patients often cannot active straight leg raise or extend the knee
Management of ligament injuries, meniscal injuries and PFPS
- Education on condition, sympt management and self management strategies
- Advise on relative rest during acute phase to gradually increase activity
- Modify lifestyle- aggr factors
- Continue with activities within pain limitis
- Direct to GP
- If acute knee pain persists longer than 4-6 weeks consider physio: manual therapy, mobility, strengthening, stretching, taping (PFPS)
If longer than 3 months consider ortho referral
Management for knee OA
- Education on condition, sympt management and self management strategies
- Modify lifestyle- aggr factors- ensure regular breaks
- Direct to GP
- Physio: manual therapy, mobility, strengthening, proprioception
- CSI
If no improvement and meeting CCG criteria: consider ortho referral
