Knee Competency Flashcards
Define Genu Valgum
Posture with knee close together and feet farther apart (knock-kneed) - increased Q angle
Define Genu Varus
Posture where the legs appear bowed with feet together (bow-legged) - decreased Q angle
Define Genu recurvatum
Posture seen from a lateral view, where the knee has a backward curvature (hyperextension)
What are the characteristics of the Q-angle?
Normal = 15°
Measured by creating a straight line from the ASIS to the center of patella another line through the tibial tuberosity and the same point of the patella. This difference between these two lines forms the “Q-angle”
Females typically have increased Q-angle.
Explain Muscle strength testing (0-5)
5 - muscle contracts normally against full resistance
4 - muscle strength is reduced, but muscle contraction can still move joint against resistance
3 - muscle strength is further reduced, such that the joint can be moved only against gravity (no resistance from examiner)
2 - muscle can move only if the resistance of gravity is removed
1 - only a trace or flicker of movement is seen or felt in the muscle, or fasciculations are observed in the muscle
0 - no movement is observed
What is the ROM for flexion of the knee and what muscles do this?
145-150°
- Hamstrings: Biceps femoris, semimembranosis and semitendinosis;
- Gracilis
- Gastrocnemius
- Plantaris
- Sartorius
- Popliteus
What is the ROM for extension of the knee and what muscles are responsible for this?
0°
- Rectus Femoris
- Vastus Lateralis
- Vastus Medialis
- Vastus Intermedius.
What is the ROM for Internal/external rotation of the knee?
10°
Accessory motion of the tibia/fibula as articulates with femur.
What dermatomes are responsible for sensation over the knee region and which are responsible for the patellar reflex?
Dermatomes: L4 for sensation over patella
Patellar reflex: L3/L4
What tests do you do to test the collateral ligaments of the knee?
Valgus and varus
What tests do you do to test the cruciate ligaments of the knee?
Drawer and lachman tests
What test do you do to test the meniscus of the knee?
McMurray’s and Apley’s grind test
How do you perform a Lachman’s Test?
Pt supine, examiner places cephalad hand on the distal thigh, superior to patella. Caudad hand grasps the proximal tibia. Flexing the knee to 10-30°, examiner used his caudad hand to pull the tibia anteriorly while the cephalad hand stabilized the thigh.
Positive: Increased laxity, soft or absent end point.
Indication: ACL insufficiency (injury/tear).
How do you perform a Posterior Drawer Test?
Pt supine with knee flexed to 90°. Examiner sits on patient’s foot and grasps the proximal tibia with both hands, translating the tibia posteriorly.
Positive: Excessive translation, particularly when compared to the opposite side.
Indication: PCL insufficiency, posterior capsular injury or
disruption (injury/tear)
How do you perform a McMurray’s Test?
Pt supine , with hip and knee flexed. Examiner uses caudad hand to control the ankle and cephalad hand placed on distal femur.
Lateral Meniscus: Examiner rotates the tibia into internal rotation, apply varus stress (pushes ankle toward middle w/ counterforce to femur), while continuing leg into extension
Medial Meniscus: Examiner rotates the tibia into external rotation, apply valgus stress, while continuing leg into extension.
(+) Test: Pain or a palpable click during extension
Indication: Possible medial or lateral meniscus tear
How do you perform part one of an Apley’s Grind Test: Compression test?
Pt prone with knee flexed to 90°. Use downward force on the foot to provide a compressive force on the meniscus, while rotating foot internally and externally.
Positive: Pain with rotation and/or compression
Indicates: Possible meniscal injury, collateral ligament injury, or both
How do you perform part 2 of an Apley’s Grind Test: Distraction test?
Pt prone with knee flexed to 90°. Stabilize the thigh, and apply upward traction to the leg while rotating it (traction reduces meniscal pressure, but increases ligamentous strain)
Positive: Pain with distraction and rotation
Increased ligamentous strain
Indicated: Possible collateral LIGAMENT damage
(+) Test: Relief of pain with distraction and rotation
Reduced meniscal pressure
Indication: Possible meniscus injury
How do you perform a laxity test of the patellar ligaments?
Laxity Test: One hand above and one hand below the joint. Thumbs placed against the medial side of the patella. Examiner pushes the patella laterally, assessing ROM.
Apprehension Test: When testing laxity to the point of restriction, ask the patient if the maneuver provokes any
discomfort or sense of instability.
• (+) Test: Sense of apprehension or instability
• Indication: Possible previous patellar dislocation or severe
instability
How do you perform a Patellar Compression (Grind) Test?
Patient supine and knee extended. Provide compressive load to the patella with one hand while moving the patella medial and lateral.
• (+) Test: Pain with compression
• Indication: Possible inflammation, chondromalacia, or
injury to the patellofemoral articular surfaces
How do you perform a Patella-Femoral Grinding test?
Compress patella caudally into trochlear groove and instruct patient to tighten quadriceps against resistance.
- (+) Test: Crepitus or pain
- Indication: roughness of articulating surfaces (ie: chondromalacia)
How do you perform a Patellar Glide Test?
Patient sitting or supine will slowly extend and flex the knee, while physician notes quality of the articular motion. Placing hand lightly over the patella can increase sensitivity of the test
• (+) Test: Palpable or audible crepitus, pain, or catching of the
patella
• Indication: Possible damage to the articular surface
What does a positive Lachmans test tell you?
ACL insufficiency
What test do you use to test for the ligaments and cartilage of the patella?
Laxity, apprehension, compression, grind and glide tests
What is indicative of a positive McMurray’s test and what does this mean?
Positive: Pain or a painful click during extension
Indicates: Possible medial or lateral meniscus tear
How do you perform an apprehension test to assess the patellar ligaments?
When testing laxity to the point of restriction ask the patient if the maneuver causes any discomfort or sense of instability
Positive: Sense of apprehension or laxity
Indicates: Possible previous patellar dislocation or severe instability
What does a positive patellar compression (grind) test indicate?
Possible inflammation, chondromalacia, or injury to the patellofemoral articular surfaces
What is chondromalacia?
Cartilage degeneration and softening
What conditions can patellofemoral pain be associated with?
- Chondromalacia
- Poor alignment/tracking of the patella
- Abnormal Q angle
What can cause Iliotibial band syndrome?
- Overuse
- Can be associated with bursitis
What pathology is also referred to as jumper’s knee and is a common overuse condition?
Patellar tendonitis
What is the most common cause of quadriceps tendonitis?
Overuse injuries
What is Osgood-Schlatter Disease?
- Overuse injury, common in adolescents - Avulsion of secondary ossification center of tibial tubercle -> anterior tibia gives way before patellar tendon does
What knee pathology is shown in the image?
Osgood Schlatter’s disease
What knee pathology is shown in the image?
Supracondylar fracture
What knee pathology is shown in the image?
What knee pathology is shown in the image?
Total knee arthroplasty
What knee pathology is shown in the image?
Tibia/fibula fracture
What knee pathology is shown in the image?
Tibia plateau fracture
What knee pathology is shown in the image?
Patellar fracture
What knee pathology is shown in the image?
Fibular head fracture
Reverse Lachman’s Test
Patient supine. Examiner places cephalad hand on the distal
thigh, superior to patella. Caudad hand grasps the proximal tibia. Flexing the knee to 10-30°. The proximal hand stabilizes the femur while the distal hand pushes the tibia posterior.
(+) Test: Increased laxity, soft or absent end point
Indication: PCL insufficiency/posterior capsule injury or
disruption (injury/tear)
