The Knee

Question 1

• One of the most injured joints in the body
• Supported mainly by muscles and ligaments with NO bony stability
• The largest joint in the body
• Flexion, extension and rotation as an accessory motion to extension

Answer 1

The Knee

Question 2

Note: the articular surface of the femoral condyles is much larger than the articular surface of the tibia… therefore:
As the knee is going from flexion into extension, the femur must ________posteriorly as it _________s on the tibia (so it does not run out of room to complete extension)

Answer 2

• GLIDE
• ROLL

Question 3

Note: the articular surface of the medial condyle is larger than that of the lateral condyle … therefore:

Answer 3

• The medial condyle of the femur must also glide posteriorly to use all of its articular surface
• This cause the femur to spin medially in the last few degrees of WB extension in closed chain action

Question 4

In the screw home mechanism in the weight bearing position (closed chain kinetic activity), the femur rotates _________on the tibia as the knee moves into the last few degrees of knee extension

Answer 4

medially_

Question 5

In the non-weight bearing position (open chain kinetic activity), the tibia must rotate ________ on the femur and the last few degrees of extension will LOCK the knee into extension

Answer 5

laterally

Question 6

• To unlock the knee in an open chain kinetic activity, the femur must rotate laterally on the tibia
• This accessory motion limits the knee from being a TRUE hinge joint but knee rotation will not be considered a measureable joint motion

Answer 6

Screw Home Mechanism

Question 7

The articulation between the femur and patella is the ______________ joint

Answer 7

Patellofemoral Joint

Question 8

The patella serves to increase the mechanical advantage of the ___________muscle and to protect the knee joint from harm

Answer 8

quadriceps

Question 9

the patella

• The moment arm is____________ due to the line of pull the patella adds to the quadriceps
  
  • Remember…the perpendicular distance from the muscle line of action to the joint axis
• Without the patella, this moment arm would be shorter and the joint would be at a disadvantage

Answer 9

lengthened

Question 10

• Also known as the Q-angle or the patellofemoral angle is the angle between the patellar tendon and the rectus femoris
• Determined by drawing a line from the ASIS to the midpoint of the patella and from the tibialtuberosity to the midpoint of the patella
• Normal ranges are 13-18 degrees and it is measured in knee extension
  
  • Larger in women due to their *larger by nature* pelvis
  • Patellofemoral pain syndrome (PFPS) and other patellar tracking problems can occur because of this

Answer 10

Quadriceps Angle

Question 11

most posterior of the tarsal bones
Known as the heel, the gastrocnemius & soleus attach here

Answer 11

Calcaneus

Question 12

• Lateral to and smaller than the tibia
• This bone gives the rounded shape to the lower leg
• Not a part of the knee joint but articulates with the tibia and glides as an accessory motion on the tibia during knee ROM
• Larger role of motion at the ankle

Answer 12

Fibula

Question 13

attaches to the anterior surface of the intercondylar eminence and just medial to the medial meniscus and runs superiorly and posteriorly to the lateral condyle of the femur

Answer 13

ACL

Question 14

attaches to the posterior surface of the intercondylar eminence and runs superior/inferiorly to the medial side of the ACL and attaches to the medial condyle of the anterior femur

Answer 14

PCL

Question 15

Both ACL & PCL provide stability in the ______ plane of motion

Answer 15

Sagittal plane

Question 16

ACL –prevents

Answer 16

excessive hyperextension

When the knee is slightly flexed, it limits anterior translation of the tibia on the femur

Question 17

PCL – keeps the femur from_____________on the tibia. Tightens during flexion and is less injured overall than the ACL

Answer 17

displacing anteriorly

Question 18

flat, broad ligament that provides stability to the medial side of the knee
Fibers of the medial mensicus are attached to this ligament and result in frequent tearing of the meniscus

Answer 18

MCL

Medial collateral ligament

Question 19

round and cordlike, provides stability to the lateral side of the knee (book states medial – it protects from a blow to the medial knee)
These ligaments provide stability in the frontal plane

Answer 19

LCL

lateral collateral ligament

Question 20

two half moon, wedge shaped fibrocartilagenous disks located on the superior surface of the tibia

Answer 20

Medial and Lateral Meniscus

Question 21

reduce friction and there are approximately 13 at the knee joint

• Due to the tendinous insertions around the knee

Answer 21

Bursae

Question 22

Contains important structures

• Tibial nerve
• Common peroneal nerve
• Popliteal artery

Answer 22

Popliteal Fossa

Question 23

Borders of popliteal fossa

Answer 23

1. Superior/medial – semitendinosus/semimembranosus
2. Superior/lateral – biceps femoris
3. Inferior - gastrocnemius

Question 24

goose/duck foot

• Say grace before tea
  
  • Sartorius
  • Gracilis
  • Semitendinosus

Answer 24

Pes Anserine

Question 25

Patellar tendonitis

Answer 25

Jumper’s Knee

Question 26

popliteal cyst

Answer 26

Baker’s cyst –

Question 27

housemaid’s knee

Answer 27

Prepatellar bursitis –

Question 28

Muscles of the Knee(9)

Answer 28

1. Rectus femoris 2. Vastuslateralis 3. Vastusmedialis 4. Vastusintermedius 5. Semimembranosus 6. Semitendinosus 7. Biceps femoris 8. Popliteus 9. Gastrocnemius

Question 29

* One of the more challenging disorders to treat for both the patient and the PT/PTA * Not always easy to identify this region as the source of the patient’s complaints or to isolate causes of the pain * Understanding the biomechanics of the knee and the lower extremity is essential for successful management

Answer 29

Patellofemoral Problems

Question 30

Signs and Symptoms: * Aching pain in the front of the knee, typically of gradual onset * Can be “behind” the knee * Complaints of the knee “giving way” * Thought of a protective response to pain caused by an aggravating factor such as climbing stairs * Grinding noises in the knee * Crepitus, typically benign * Pain with walking up stairs, squatting, and running and other bent-knee weight bearing activities * Pain with prolonged sitting * Mild swelling, if any * Excessive foot pronation, tight hip internal rotators/weak hip external rotators alter the pull of the quadriceps on the patella * Patellar tilt, seen with palpation

Answer 30

Patellofemoral Problems

Question 31

* Inflammation of the patellar tendon, often seen with jumping activities * Referred to as Jumpers Knee * Seen with sports that require fast running and abrupt changes in direction

Answer 31

Patellar Tendonitis

Question 32

Signs and Symptoms: * Anterior knee pain * Local, point tenderness * Small amount of local swelling

Answer 32

Patellar Tendonitis

Question 33

Inflamed and painful infrapatellar fat pad Often confused with patellar tendonitis Signs and Symptoms: * Pain just below the patella * Movement of the knee typically aggravates the symptoms * Tender to palpation * Swelling in the anterior knee

Answer 33

Fat Pad Syndrome

Question 34

* Typically caused by a blow to the outside of the knee or a high energy twisting maneuver * Forces result in stretching and a valgus force on the medial tibiofemoral joint * Graded on a system of I -\> III

Answer 34

Medial Collateral Ligament Sprain (MCL)

Question 35

* LCL is on the lateral side of the knee and is not frequently involved with high-level activities * Injured by a blow to the medial side of the knee, resulting in a varus (from inside) stress to the knee joint * Confirmed with tenderness to palpation as well as possible laxity with a varus

Answer 35

Lateral Collateral Ligament Sprain (LCL)

Question 36

Symptoms: * Mild tenderness over the affected ligament * Usually no swelling * For an MCL sprain, when the knee is bent to 30 degrees and force is applied to the outside of the knee, pain is felt, but there is no laxity/looseness

Answer 36

Grade I Ligament Sprain

Question 37

Symptoms: * For MCL, significant tenderness on the inside of the knee for the medial collateral ligament * Some swelling seen over the ligament * When the knee is stressed, there is pain and laxity in the joint and there is a definite end point/end feel to the joint

Answer 37

Grade II Ligament Sprain

Question 38

Symptoms: * There is a complete tear of the ligament * Pain can very and is sometimes less than that of a grade II sprain * When the knee is stressed, there is significant joint laxity * The patient might complain that there is significant instability or “wobbly” feeling in the joint

Answer 38

Grade III Ligament Sprain

Question 39

* Injury to the ACL can be from contact or noncontact causes * Situations that place a loaded, weight bearing knee in a combined position of flexion, valgus and rotation of the tibia on the femur can rupture the ACL in a noncontact manner * Rapid changes in direction * Once the ACL is stretched or ruptured, it will not heal on its own * Sometimes accompanied by medial meniscus tears and MCL sprains * Unhappy Triad * The ACL and PCL do not follow the same grading scale as for MCL and LCL sprains * They are either damaged or not damaged – there is no middle ground

Answer 39

Ruptured Anterior Cruciate Ligament

Question 40

Signs and Symptoms: * “Pop” in the knee is either felt or heard by the patient * Followed by rapid effusion/swelling in the joint cavity * Nausea immediately after the injury * Positive special testing for ligament instability must be completed within 5 minutes of injury otherwise, the test will be invalid due to muscle guarding * Diagnosis by a physician in conjunction with an MRI (magnetic resonance)

Answer 40

Ruptured Anterior Cruciate Ligament

Question 41

* Account for 3-20% of all knee injuries * Most injuries occur from athletics, MVAs or industrial accidents * Athletic – fall onto a flexed knee with foot in plantar flexion * Hyperextension * Dashboard injuries

Answer 41

Posterior Cruciate Ligament Tear

Question 42

Signs and Symptoms: * Pain * Positive “Sag” Test – giving the illusion when the knee is flexed that it is bending backwards * Positive diagnostic imaging on an MRI

Answer 42

Posterior Cruciate Ligament Tears

Question 43

* Menisci help to make a more concave surface for the condyles to rest and glide on and make the knee more stable * Medial meniscus tears more easily than the lateral because it is attached to the medial collateral ligament and is more restricted during movement * Lateral meniscus is attached only at the back of the knee and moves more freely as the knee is bent and straightened * Torn when twisted suddenly and one or more menisci become caught between the knee

Answer 43

Meniscus Tears

Question 44

Signs and Symptoms: * Isolated tears develop mild swelling slowly over several hours or more * Pain * Popping * Locking * Giving way of the knee

Answer 44

Meniscus Tears

Question 45

* Knee is subjected to sports-induced trauma at the center of bone growth in skeletally immature athletes. * Epiphyseal plates are zones of cartilage cells from which new bone is formed * The joint capsule and ligaments near these growth plates are 2-\>5x stronger than the growth plate itself * Because the epiphysis is responsible for bone growth, injuries involving this area may alter the length of the involved bone

Answer 45

Epiphyseal Injuries (growth plate)

Question 46

* A group of symptoms involving the tibial tubercle epiphysis * Most likely to involve males age 12-16 and females 10-14 * Traction of the quadriceps muscle inflames and irritates the layers of the tibial tubercle, causing it to swell * If the femur is growing faster than the quadriceps, the quadriceps will exert undue pressure on the growth center of the tibia

Answer 46

Osgood-Schlatter Condition

Question 47

Signs and Symptoms: * Pain over the tibial tubercle * Swelling over the tibial tubercle * Weakness in the quadriceps muscle group * Increased pain and swelling with activity * Visible lump * Pain to the touch over the affected area

Answer 47

Osgood-Schlatter Condition

Question 48

* Inflammation of the band that begins at the hip and extends to the knee on the outside of the leg * Irritation usually occurs over the outside of the knee joint at the lateral epicondyle * Where the IT band crosses bone and muscle at this joint * Should be smooth and gliding motion * When inflamed, motion becomes painful and guarded * People who suddenly increase their level of activity are prone to developing

Answer 48

Iliotibial Band Syndrome

Question 49

* Typically a result of high-energy trauma * Fractures vary in location and severity * Patellar fractures are a result of direct impact to the anterior knee * Knee strikes hard ground or some other hard surface * Distal femoral and proximal tibial fractures may occur from violent twisting injuries such as falls from heights

Answer 49

Fractures

Question 50

What is involved in the terrible triad?

Answer 50

* Medial Meniscus * Anterior Cruciate Ligament, * Medial Collateral Ligament. MAM

Question 51

Normal ranges of the Q-angle are between \_\_\_&\_\_\_degrees and it is measured in knee\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 51

1. 13-18 2. extension