Assess gait pattern while walking. Look at alignment and for any abnormal knee thrusting movements.
Knee Examination
Knee Examination
Human anatomy alignment
Knee muscle and tendon attachments
Muscle and tendon attachments
Muscle attachments around knee allow knee range of motion (ROM)
Assess gait pattern
MCL
Apply a valgus force at 0° & 30 ° knee flexion
LCL
Apply a varus force at 0° & 30 ° knee flexion
LCL tear
LCL tear on varus stress testing
Examine hip rotation and assess femoral neck version
Hip IR & ER
Supine Gage
Traditional femoral neck anteversion test is done in prone position
Anterior Cruciate Ligament (ACL)
ACL tests
- Lachman test
- Anterior Drawer test
- Pivot
Lachman test (View 1)
Lachman test (View 2)
Lachman test demonstrating torn ACL
Anterior Drawer Test
Anterior and posterior drawer tests: start test by first palpating the tibia in relation to the medial femoral condyle. Assess tibia position and ascertain if it is in an anatomical position before commencing with the Anterior and Posterior drawer tests.
Anterior Drawer Test demonstrating torn ACL
Anterior and posterior drawer tests: start the test by first palpating the tibia in relation to the medial femoral condyle. Assess the tibia position and ascertain if it is in an anatomical position before commencing with the Anterior and Posterior drawer tests.
Pivot Test
Posterior Cruciate Ligament (PCL)
- Observation: posterior sag, hyperextension
- Posterior Drawer test
Posterior Drawer Test
Anterior and posterior drawer tests: start the test by first palpating the tibia in relation to the medial femoral condyle. Assess the tibia position and ascertain if it is in an anatomical position before commencing with the Anterior and Posterior drawer tests.
Posterolateral Corner (PLC)
PLC tests
- Posterolateral drawer test
- Dial test at 30°: positive if > 30° external rotation
- Dial test at 90°: if positive combined PCL & PLC instability
- External recurvatum test
- Reverse Pivot test
Posterolateral drawer test
- Position: Supine with test knee at 90° knee flexion & 15° external rotation.
- Perform a posterior drawer & external rotatory force. Assess for éposterolateral translation.
- + test: Lateral tibia plateau moves posteriorly with a stable medial plateau.
External rotation recurvatum test
- Supine position: Hold foot and externally rotate at 0° knee extension.
- Support proximally to the knee joint with other hand and hyperextend the knee.
- Compare to contralateral side. Hyperextension indicative of PCL & PLC instability.
Reverse pivot test
- Supine position with starting knee position of 90°: Extend and at 80° knee flexion apply a valgus & externally rotation force then extend knee while applying this force.
- Compare with contralateral side
- Positive test: tibia reduces from subluxation in flexion when the Iliotiobial is a predominant knee flexor and then becomes a predominant extensor moment to the knee at end range of knee extension.
Dial test
- Supine or prone position: Hold foot and externally rotate at 30° & 90° knee flexion. Compare bilaterally.
- Dial test at 30°: positive if > 30°(average) external rotation
- Dial test at 90°: positive > 37° (average) With increasing ER at 90° combined PCL & PLC.
Dial at 30
Dial at 90
PLC instability
Dial test at 30° demonstrating right knee PLC instability. Repeat test at 90° to exclude associated PCL tear.
Supine dial
Comparative supine with prone dial to assess for false positive test due to antero-medial knee instability that can also causes and increase in external foot rotation. During supine dial test confirm no antero-medial instability.
External rotation recurvatum test
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- Supine position: Hold foot and externally rotate at 0° knee extension.
- Support proximally to the knee joint with the other hand and hyperextend the knee.
Reverse pivot test
- Supine position with starting knee position of 90°: Extend and at 80° knee flexion apply a valgus & externally rotation force then extend knee while applying this force.
- Compare with contralateral side
- Positive test: tibia reduces from subluxation in flexion when the Iliotiobial is a predominant knee flexor and then becomes a predominant extensor moment to the knee at end range of knee extension.
Exclude vascular injury & assess common peroneal nerve function.
Combination of ACL & PCL ligament injury.
Multi-ligament instability
Combined ACL & PCL instability
5 months post surgery stable knee
Meniscus
Various meniscus tests are available and range from palpation to loading the meniscus with direct axial compression by the examiner or by the utilization of compression – Using the patient’s own body weight to generate a force in either standing or walking with varying degrees of knee flexion. The principles are based on loading the meniscus while testing in varying degrees of knee flexion ± rotational movements by a force transmission. A few common tests are highlighted.
Commonly used meniscus tests:
- Palpate joint line tenderness
- McMurray test
- Thessaly test
- Apley test
Meniscus tests
The Apley test
- Position: patient in a prone position with the tested knee at 90° of flexion. The examiner holds the patient heel & applies an axial compression load while rotating the tibia on the femur.
- Positive test: + pain on axial compression
Thessaly test
- Position: Patient stands on a single leg to be tested & then flexes the knee to 20°. The clinician supports the patient by holding their outstretched hands. The patient then rotates their knee and body 3 times, both internally and externally while in a position of 20° of knee flexion.
- Positive test: + joint line pain ± click.
McMurray test
- Position: Patient is supine. The examiner holds the patient’s foot and flexes the patient’s hip and knee and palpating the knee joint line for a pop or click as the tibia is internally and externally rotated while extending the knee.
- Positive test: + click or pop
Duck walking
- Deep knee flexion predominantly loads the posterior horn of the meniscus and loading the meniscus in this position is used to test for posterior horn tears: Duck walking i.e. loading the meniscus in deep flexion while using the patient’s body weight as a force may be used to test for posterior horn tears.
- Positive test: + pain
Patellar
Examination: focus on regional & global assessment
- Examine Hip anteversion, tibia rotation & foot position profile
- Observation: J sign
- Palpation
- Assess lateral translation
- Apprehension test
Patellar: Q angle
Assess regional & global alignment
Factors affecting patella tracking
Examine hip:
Assess hip rotation and assess femoral neck version
Hip range of motion: Internal & External rotation
Assess femoral neck anteversion
Modified Craigs test
Traditional femoral neck anteversion test (Craig test) is done in a prone position with hip in neutral position with knee flexed to 90°. Palpate the greater trochanter and rotate femur internally while palpating the greater trochanter. When greater trochanter lies at most lateral aspect the angle measurement is taken from the angle of rotation to neutral reference point.
Examine hip:
Assess hip rotation and assess femoral neck version
Hip range of motion: Internal & External rotation
Assess femoral neck anteversion
Modified Craigs test
Low arch foot with genu valgus increases Q angle with increased risk of Patellar femoral dysfunction
Knee extensor mechanism
Straight leg raise
If extensor mechanism absent assess patellar height position & palpate for any structural defect.
Intact extensor mechanism allows knee Range of motion (ROM). Disruption thereof causes the inability to extend the knee
+ J sign
Palpation
Assess lateral translation & tilt
Assess lateral translation & also quantify the degree of lateral translation.
Increased lateral translation after recurrent Patellar dislocation.
Patellar dislocation: Torn MPFL with apprehension on stability testing.
Patellar Apprehension Test
Apply valgus force to patellar & flex from full extension. Positive test: Patient apprehend movement due to pain & patellar subluxation.
