Knee evaluation

1. When did the injury occur?

2. How did it happen? (etiology)

a) were you planted? turned/twisted?

b) did someone hit you?

c) did you hear anything? pop? crack? grinding?

d) did it occur during a game or practice?

e) what was the playing surface like? wet/dry?

f) what type of pain is the patient experiencing ?

Where?, when?, sharp?, aching type pain? (dull, aching pain is usually indicative of degenerativeintra articular pain.)

g) did the knee swell and if so, did the swelling occur fairly rapidly over a 6-8 hour period (ACL) or did it take several days to swell. (meniscus)

2. what functional limitations does the patient have ?

running
cutting
pivoting
twisting
climbing or descending stairs

3. Previous history of injury to that area?

4. Sight/visual evaluation

a) swelling? Is it extra capsular or intra articular ?

intraarticular = ACL, meniscus.
extra-articular = bursae, MCL - LCL ligament tears

b) deformities?

c) discoloration? not a common finding

d) quad tenses (bilateral) - full extension? apprehensive?

5. Palpation evaluation

a) feel for heat - hemarthrosis, blood in the joint is hotter than synovial fluid

b) check patellar movement - medial, lateral, proximal, and distal check for tendencies of patellar apprehension or subluxation

c) check palpable painful sites, ie., medial and lateral joint lines, ligament attachment sites

6. Stress tests

Ligamentous instability

one plane medial
one plane lateral
one plane anteriorly
one plane posteriorly
anterior medial rotary
anterior lateral rotary
posterior medial rotary
posterior lateral rotary

Picture
Always test the normal side first, apply the stress firmly but gently feel for the ligament end point. The muscle must be relaxed. (this picture is an example of poor patient positioning. The patient is not relaxed when sitting up and his quad muscles are contracted.)

A. check medial and lateral collaterals at 0 and 30 degrees

Valgus, full extension Valgus, 30⁰

Varus, 30⁰

B. Anterior Drawer test for anterior cruciate and posterior drawer for posterior cruciate

(1) check with foot straight

(2) check with the foot turned in and out internal rotation places additional stress on the
posterior lateral capsule. External rotation places additional stress on the medial posterior capsule.

C. Lachman's test - ACL instability

Knee is bent 20-30⁰, the examiner attempts to displace the tibia on the femur. The muscles must be relaxed. Pay special attention to the hamstring muscle group.

C. Modified Lachman's - the leg is supported by the table. This test is very good if the athlete's leg is too large to hold up or the examiners hands are too small to get a good grip.

D. Posterior Sag test for posterior cruciate instability. The examiner must look at the anterior tibial borders from the side with the knees bent at 90⁰.

E. Mc Murray's click test for the integrity of the meniscus. This test is done to "pinch" the menisci against the femur. Internal rotation of the tibia on the femur stresses the posterior medial and the anterior lateral menisci while external rotation stresses the anterior medial menisci and the posterior horn of the lateral menisci.

F. Apley's grind test - Apley's distraction test, tests for meniscal impingement. This is a seldom used test with questionable accuracy.

Probable injured structures in full extension [ positive 2+ laxity ]

MCL

posterior medial capsule

ACL

PCL

medial quad muscles

semimembranosus

Positive findings in full extension are indicative of major ligament disruption

Probable injured structures with the knee flexed to 30 degrees

medial collateral ligament

posterior oblique ligament

posterior cruciate ligament

these injuries are graded 1 2 3 4 from less to worse

some physicians may also used a + or - to differentiate

between lesser or greater degrees of each finding.

Grade 1 = 5 mm of joint opening with good end point

Grade 2 = 5+ to 10 mm of joint opening with good end point

Grade 3 = over 10 mm with spongy end point

Grade 4 = total joint dislocation

Varus adduction test

Probable injured structures in full extension

lateral collateral ligament

posterolateral capsule

arcuate - popliteus complex

biceps femoris tendon

PCL

ACL

lateral head of gastroc

30 degrees of flexion

LCL

posterior lateral capsule

arcuate complex

iliotibial band

biceps femoris tendon

Lachman's test - ACL

This test is designed to help take the hamstring out of helping

provide stability when testing the integrity of the ACL or PCL ligaments.

• The knee is flexed 20-30 degrees with the thigh supported by the upper hand and the other hand attempts to distract or push the tibia anteriorly or posteriorly on the femur.

Modified Lachman

Supports the thigh with the table.

This method is especially helpful for examiners with small hands or

when examining a patient with larger heavy legs.

• The leg-thigh is supported by the table. The knee is flexed to 20 degrees and the foot is held between the examiners legs. This allows the examiner to have both hands free from support of the leg in order to better control the tibial movement.

ACL Injury

Positive tests are indicative of ACL disruption with some posterior oblique ligament and arcuate ligament injury also. It may be difficult to test some legs because of there size and muscle mass. Many times, an EUA, evaluation under anesthesia may be necessary to determine the true laxity. A machine, the KT1000 is used by some physicians to measure the tibial displacement of the tibia in relation to the femur.

Posterior sag test - gravity drawer test

The patient is supine, hip flexed to 45 degrees, knee flexed to 90 degrees

the tibia will drop back on the femur as the result of a torn posterior cruciate ligament.

Anterior drawer test

knee flexed to 90

hip flexed to 45

the hamstrings must be relaxed

• the foot may be rotated medial and laterally to determine the extent of any rotary instability.

KT 1000 Testing

The KT 1000 by MedMetric Corp. San Diego, CA. is a device that measures the anterior tibial translation in reference to the patella and provides a definitive comparison between the affected and unaffected limbs. Measurements are taken at various tensions (ft lbs of pull) and finally at a maximum level of pull. This machine should not replace the clinical expertise of the clinician but is a very good adjunct tool for determining ACL laxity.

Lateral pivot shift test [ McIntosh test ]

tests for anterolateral rotary instability

push forward on the tibia at the knee

• pull back on the ankle, flex the hip to 20 degrees, flex the knee 5 - 10 degrees

  medial rotation of approx. 20 degrees. Positive tests occur at approx. 20-40 degrees of flexion. This is a difficult test to perform clinically. It is best performed under anesthesia.

Jerk test of Hughston

similar to the pivot shift test except that the hip is flexed to 45 degrees.

the knee is flexed to 90 degrees.

• at approx. 20-30 degrees of flexion the tibia will shift forward causing a subluxation of the lateral tibial plateau

Crossover test

patient is standing

cross the unaffected leg in front of the affected leg

the involved foot is stabilized by the examiner.

results are the same as a pivot shift.

• This test should be performed on chronic knee patients only.

Positive test indicates the following injured structures

ACL

posterolateral capsule

posteromedial capsule

MCL - deep fibers

iliotibial band

posterior oblique ligament

arcuate - popliteus complex

Meniscus tests

McMurray -

• the knee is flexed and extended with the knee rotated during the exam in both internal and external movements any intraarticular clicking or popping should be considered a positive finding and warrants further examination.

Bounce home -

the knee is allowed to bounce home into full extension for the last 10-15 degrees

this checks for any mechanical blocking of the joint by an articular loose body.

Apley's distraction - compression

rotation with distraction checks ligaments

rotation with compression checks meniscus

Plica tests

many plica pathologies mimic meniscal injuries

position the patient in a supine position

move the patella medially while flexing the knee

popping noise or feelings around the patella may indicate a plica.

Apprehension sign

indicates a laterally subluxating patella.

Q-angle

patellar mis alignment

Clarke sign

roughness under the patella - ie: chondromalacia

Waldron test

popping under the patella when the patient does a deep knee bend.

indicative of chondromalacia

Noble I.T. band compression test

patient is laying on the unaffected side

flex the knee to 90 degrees

flex the hip to pt. comfort

• extend the leg while applying pressure over the distal I.T. band pain when extending is indicative of positive findings.

Slocum test

little used, measures anterior rotary instabilities

Losee test

anterior lateral rotary instability

6. Functional tests

a) walking - check gait for heel/toe strike

b) pull heel to butt

c) deep knee bends

d) does the patient complain of the knee giving way?

e) single leg broad jump distance

meniscal lesions give way to slow speed twisting and bending

• ACL tears have a tendency to feel unstable when the patient is running, cutting, or stopping.

7. Refer to doctor for further examination and possible x-rays