Knee Pathologies Flashcards
Knee Joint Components
medial Compartment of the tibiofemoral joint
lateral compartment of the tibiofemoral joint
Patella-femoral Joint
Tibiofemoral Joint
Contains fibrocartilaginous menisci
- Act as shock absorbers and act to distribute load evenly
Knee Ligaments (4) and function
Anterior Cruciate Ligament (ACL)
- Prevents abnormal internal rotation of the tibia
- Prevents anterior translation of the femur on the tibia
Posterior Cruciate Ligament (PCL)
- Prevents hyperextension and anterior translation of the femur
medial Collateral ligament (MCL)
- Resists valgus force
Lateral Collateral Ligament(LCL)
- Resists varus force
- Resists abnormal external rotation of the tibia
OA of the knee: Predisposition
Previous meniscal tears
ligament injuries
malalignment
OA of the knee treatment
Young patients with isolated medial compartment OA
- Osteotomy of proximal tibia
- Uni-compartmental knee replacement
Young patients with isolated lateral compartment OA
-Uni-compartmental knee replacement
Patients with substantial pain and disability
- Knee replacement
Meniscal Injuries Aetiology
Twisting force on loaded knee
Meniscal Injuries Presentation
Localised pain to the joint line
- Medial or lateral
Effusion the following day
Catching or locking sensation
- True knee locking occurs in meniscal tears
- Caused by a significantly torn meniscus flipping over and becoming stuck in the joint line
Feeling of knee giving way
Pain on tibial rotation
Positive Steinmann’s test
ACL Ruptures Aetiology
High rotational force
- turning the body laterally on a planted foot
ACL ruptures presentation
‘Pop’ sound or feeling
Haemarthrosis and swelling within an hour
Deep knee pain
Rotatory Instability
- with giving way on turning
- main complaint
Excessive anterior translation of tibia on anterior drawer test
ACL deficiency
⅓ will compensate well
⅓ will manage by avoiding certain movements
⅓ will do poorly with their knee giving way during normal movements
ACL rupture Treatment
Physiotherapy
-Strengthening of quadriceps and hamstrings aid compensation
Patients who cope poorly in day to day activities may require ACL reconstruction
- tendon graft being passed through tibial and femoral tunnels at the usual location of ACL in knee and attachment to bone
May take up to a full year to recover
PCL ruptures aetiology
Direct blow to anterior tibia when the knee is flexed
hyperextension
PCL rupture treatment
isolated PCl rupture
- Conservative management
Conservative
- only those with severe laxity with frequent hyperextension or feeling unstable when descending stairs are considered for reconstructive surgery
- Use of cadaveric achilles tendon autograft
Medial Collateral Ligament tears aetiology
Valgus Stress
Medial Collateral Ligament tear Treatment
Usually heals with little or no instability
Acute MCL tears
- Hinged knee brace
Chronic MCL instability
- MCL tighteninh
- Reconstruction with a tendon graft
Lateral Collateral Ligament tears aetiology
Varus Stress
hyperextension with various impact
Lateral Collateral Ligament tears Consequences
often damage to perineal nerve
Lateral Collateral Ligament Tears treatment
Surgical with early repair
Late reconstruction with tendon graft
Menisci Blood Supply
Only have arterial blood supply to the outer ⅓
Meniscal Tear aetiology
In young patients
- high impact sports
- Acute ACL tears
Meniscal Tear Types
Large Longitudinal Tears
Degenerative
Large Longitudinal Meniscal Tears
Large bucket handle tears with subsequent knee locking due to the meniscal fragment flipping into the intercondylar notch
Degenerative meniscal Tears
Can occur spontaneously or with very little injury
have complex patterns
- Horizontal
- Longitudinal
- Radial components
1st stage in the development of knee OA
Positive Steinmann’s test
Meniscal Tears treatment
Repair
-only if fresh longitudinal tears in the outer ⅓ of the meniscus in young patients
Arthroscopic Meniscectomy
- If repair fails
Steroid injections
- Aid symptoms
Arthroscopic Partial Meniscectomy
- In acute cases that don’t settle after 3 months
Extensor Tendons
Patellar Tendon
Quadriceps Tendon
- Tends to pull the patella slightly laterally
Extensor Tendon Rupture Aetiology
Rapid contractile force
Heavy lifting
Fall
Spontaneous
Extensor Tendon Rupture Risk Factors
Tendonitis Chronic Steroid USe Diabetes RA Chronic renal failure Use of quinolone antibiotics
Extensor Tendon Rupture Investigations
Straight leg raise High lying patella - Patellar Tendon Rupture Low lying patella - Quadriceps tendon rupture
Extensor Tendon Rupture Treatment
No steroid injections
- due to increased risk of tendon rupture
Surgical tendon to tendon repair
Surgical reattachment of the tendon to the patella
Patellofemoral Dysfunction Risk Factors
Female gender
Joint hypermobility
Genu valgum
Femoral Neck anteversion
Patellofemoral Dysfunction Presentation
Anterior knee pain Grinding or clicking at front of knee Pseudolocking - Only temporal difficulty in straightening the leg - Can spontaneously resolve
Patellofemoral Dysfunction Treatment
Physiotherapy
Taping
Surgery
- Last resort
Patellar Dislocation Direction
Always laterally
Patellar Dislocation X-ray appearance
Small Opacification
-Osteochondral fracture due to the medial patellar facet striking the lateral femoral condyle
Lipo-haemarthrosis
Patellar Dislocation Risk Factors
Ligamentous Laxity Female Gender Shallow trochlear groove Genu algum Femoral neck anteversion Patella Alta - High rising patella
Patellar Dislocation Treatment
Physiotherapy
Tibial tubercle transfer
