Conditions of the Knee

Question 1

ACL Sprain or Tear

Answer 1

Definition:
Partial or complete tearing of the anterior cruciate ligament (ACL) of the knee
ACL: limits anterior translation of the tibia in relation to the distal femur
Differential Diagnosis:
Fracture (severe bruising or swelling, cannot weight bear)
Patellar or knee dislocation
Meniscus or collateral ligament tear
PCL sprain or tear
Osteoarthritis of the knee

History:
Mechanism of injury:
Running with an abrupt change in direction or landing from a jump or hyper-extension of the knee
Deep knee pain following trauma
Potential audible ‘pop’ or ‘snap’ at the time of injury
Knee swelling in <2 hours
Often associated with the “terrible triad” or “unhappy triad
ACL, MCL and medial meniscus tear

Physical:
Inspection:
Joint deformity or bony abnormality
Palpation:
Joint line (meniscus) and collateral ligaments for tenderness
Motion:
AROM & PROM: limited in extension due to pain
RROM: WNL or weak due to pain
Neurovascular:
Unremarkable

Question 2

ACL Sprain or Tear Tests

Answer 2

Special Tests:
LACHMANS TEST (ANTERIOR)
(+) Pain with anterior translation -> ACL Sprain
(+) Excessive motion -> ACL rupture

LACHMANS TEST (ANTERIOR)
(+) Pain with anterior translation -> ACL Sprain
(+) Excessive motion -> ACL rupture

Question 3

PCL Sprain or Tear

Answer 3

Definition:
Partial or complete rupture of the posterior cruciate ligament (PCL) of the knee
PCL: limits posterior translation of the tibia in relation to the distal femur
Differential Diagnosis:
Fracture (severe bruising or swelling, cannot weight bear)
Patellar or knee dislocation
Meniscus or collateral ligament tear
ACL sprain or tear
Osteoarthritis of the knee

History:
Mechanism of injury:
Fall on a flexed knee (A->P force on proximal tibia) or hyperflexion or hyperextension injury
Pain : deep knee pain after injury
Potential audible ‘pop’ or ‘snap’ at the time of injury
Knee swelling in <2 hours
Sensation of instability or apprehension
Following injury most are able to walk and may not know they are injured

Physical:
Inspection:
Joint deformity or bony abnormality
Posterior sag sign– tibia drops posteriorly when supine with knees bent
Palpation:
Joint line (meniscus) and collateral ligaments for tenderness

Physical:
Motion:
AROM & PROM: limited due to pain
RROM: WNL or weak due to pain
Neurovascular:
Unremarkable

Question 4

PCL Sprain or Tear

Answer 4

Special Tests:
POSTERIOR DRAWER
(+) Pain -> PCL strain
(+) Excessive motion -> PCL rupture

LACHMANS TEST (POSTERIOR)
(+) Pain with posterior translation -> PCL Sprain
(+) Excessive motion -> PCL rupture

Question 5

MCL Sprain or Tear

Answer 5

Definition:
Partial or complete tearing of the medial (tibial) collateral ligament (MCL) of the knee

Differential Diagnosis:
Medical meniscus or ACL damage
Patellar subluxation or dislocation
Avulsion or tibial plateau fracture

History:
Acute medial knee pain usually following a single traumatic event
Valgus force: lateral to medial force
Audible ‘pop’ or tearing sensation at time of injury
Knee swelling?
Knee will feel weak or unstable

Physical:
Inspection:
Possible swelling or bruising
Palpation:
Point tenderness over MCL
Joint line (meniscus)
Motion:
AROM & PROM: limited due to pain
RROM: WNL
Neurovascular:
Unremarkable

Question 6

MCL Sprain or Tear

Answer 6

Special Tests:
VALGUS STRESS TEST
(+) Pain – MCL Sprain
(+) Increased motion or gapping – MCL Rupture

Question 7

LCL Sprain or Tear

Answer 7

Definition:
Partial or complete tearing of the lateral (fibular) collateral ligament (LCL) of the knee
Differential Diagnosis:
ITB Syndrome
Meniscus Tear
Biceps Femoris Tendinopathy
Tibial plateau or Fibular Head Fracture
ACL Sprain/Tear

History:
Acute lateral knee pain usually following a single traumatic event
Varus force: medial to lateral force
Audible ‘pop’ or tearing sensation at time of injury
Knee swelling?
Knee will feel weak or unstable

Physical:
Inspection:
Possible swelling or bruising
Palpation:
Point tenderness over LCL (figure 4 position)
Motion:
AROM & PROM: lateral knee pain with full extension
RROM: WNL or limited due to pain
Neurovascular:
Unremarkable
Rule out common peroneal nerve pathology – runs in this area

Question 8

LCL Sprain or Tear

Answer 8

Special Tests:
VARUS STRESS TEST
(+) Pain – LCL strain
(+) Increased motion/gapping – LCL Rupture

Question 9

Meniscus Tear

Answer 9

Definition:
Tear or derangement of the fibrocartilaginous discs between the tibial & femoral condyles within the knee joint
Differential Diagnosis:
Knee DJD or Osteoarthritis
Osteochondritis Dissecans
ACL, PCL, MCL or LCL injury
Patellofemoral syndrome
ITB Syndrome
Terrible Triad***

History:
Mechanism of Injury:
Repetitive activities of the knee, planting and twisting motions or secondary to osteoarthritis
Joint line pain
Possible joint locking, catching, clicking, crepitus or sensation of giving way (instability)
Swelling usually occurs as a delayed symptom

Physical:
Inspection:
Possible swelling or redness ~50% of cases
Palpation:
Joint line tenderness**
Motion:
AROM & PROM:
Pain at end range
Mechanical block to motion or locking can occur with displaced tears
RROM: WNL or limited due to pain
Neurovascular:
Unremarkable

Question 10

Meniscus Tear Special Tests

Answer 10

Special Tests:
APLEYS COMPRESSION TEST
(+) Pain or crepitus with compression and rotation -> meniscal lesion

APLEYS DISTRACTION TEST
(+) DECREASED pain or crepitus with knee distraction

MCMURRAYS TEST
(+) Pain or crepitus -> meniscal lesion
Valgus force with external rotation -> lateral meniscus
Varus force with internal rotation-> medial meniscus

Question 11

Terrible (unhappy) Triad

Answer 11

Commonly affected together:
Medial Meniscus
ACL
MCL

Question 12

Iliotibial Band Syndrome

Answer 12

Definition:
Inflammation & irritation of the distal portion of the iliotibial tendon as it rubs against the lateral femoral condyle
Differential Diagnosis:
Biceps femoris tendinopathy
LCL sprain
Lateral meniscal injury
Chondromalacia patella
Trochanteric bursitis often coexists

History:
Pain: diffuse, lateral knee pain that starts after activity, can also have pain over the greater trochanter
Worse:
Continued activity
Running up hill or up/down stairs
There may be an audible repetitive popping noise in the knee when walking or running

Increased activity will change the dull ache to a sharp and stabbing pain

Physical:
Inspection:
Unremarkable or possible swelling/edema at distal ITB
Palpation:
Tenderness ~2cm above lateral joint line
Tenderness over greater trochanter
TFL/glute max hypertonicity or MFTP

Physical:
Motion:
AROM & PROM:
Pain with knee flexion/extension
Hip adduction (tenses ITB)
RROM:
May show decreased strength of knee extensors, flexors and hip abductors
Neurovascular:
Unremarkable

Question 13

Iliotibial Band Syndrome Special Tests

Answer 13

Special Tests:
OBERS (Modified)
(+) Hip Pain -> Hip joint pathology
(+) Trochanteric Pain -> Trochanteric bursitis
(+) Decreased ROM – ITB contracture

Question 14

Patellar Dislocation

Answer 14

Definition:
Loss of normal articulation between the patella & patellar groove of the distal femur.
Dislocation is usually lateral, can lead to chronic subluxation or recurrent dislocations
Differential Diagnosis:
ACL, MCL, LCL sprain
Fracture of patella or subchondral fracture
Meniscal tear
Chondromalacia patellae

History:
Knee pain (may look very similar to moderate to severe knee sprain)
History of direct or indirect trauma to knee (physical blow or twisting while the foot is planted)
Possible grinding or tearing sensation during injury
May have heard a pop with dislocation and a second pop with spontaneous relocation
Patient often expresses apprehension about knee movement or during activities

Physical:
Inspection:
Possible swelling or bruising over vastus medialis
Knee will often be flexed (30-45*)
Can often visualize the lateral displacement
Palpation:
Patella will not be in the normal location (can compare with the other knee)
Myospasm or trigger points in vastus muscles

Physical:
Motion: limited & painful, but possible
AROM: will show abnormal tracking (J-sign)
PROM: painful, possibly limited at end range
RROM: WNL or limited due to pain
Neurovascular:
Should be conducted but often unremarkable

Question 15

Patellar Dislocation Special Test

Answer 15

PATELLAR APPREHENSION TEST
(** Patient is apprehensive about the movements)

Question 16

Chondromalacia Patella

Answer 16

Definition:
Premature degeneration of the patellar cartilage
During the movement from flexion to extension, different parts of the patella articulate with the femoral condyles
The odd facet does not come into contact with the femoral condyles until at least 135 Degrees of flexion is reached.
Incorrect alignment or mal-alignment of the patellar movement over the femoral condyles can lead to patelofemoral arthralgia
Differential Diagnosis:
ACL, MCL, LCL sprain
Fracture of patella or subchondral fracture
Meniscal tear
Patellofemoral Syndrome

History:
Knee pain
History of direct or indirect trauma to knee or NO trauma
Possible grinding or tearing sensation during walking up or down stairs
A general pain

Physical:
Inspection:
No to minimal swelling over knee area due to wear and tear
Patella might be laterally displaced during walking
Palpation:
Patella will not be in the normal location (can compare with the other knee)
Myospasm or trigger points in vastus muscles

Physical:
Motion: NOT limited & NOT painful (No nerves in cartilage), but possible
AROM: will show abnormal tracking (Lateral)
PROM: painful, possibly limited at end range
RROM: WNL
Neurovascular:
Should be conducted but often unremarkable

Question 17

Chondromalacia Patella Special Tests

Answer 17

Special Tests:
Clarks Patellar Grind Test
(+) Grinding sensation or pain

Question 18

Patellofemoral Syndrome

Answer 18

Definition:
Patellofemoral pain syndrome occurs when nerves sense pain in the soft tissues and bone around the kneecap.
These soft tissues include the tendons, the fat pad beneath the patella, and the synovial tissue that lines the knee joint.
In some cases of patellofemoral pain, a condition called chondromalacia patella is present. Chondromalacia patella is the softening and breakdown of the articular cartilage on the underside of the kneecap. There are no nerves in articular cartilage—so damage to the cartilage itself cannot directly cause pain. It can, however, lead to inflammation of the synovium and pain in the underlying bone.

Differential Diagnosis:
ACL, MCL, LCL sprain
Fracture of patella or subchondral fracture
Meniscal tear
Patellofemoral Syndrome

Causes
Overuse
In many cases, PFPS is caused by vigorous physical activities that put repeated stress on the knee —such as jogging, squatting, and climbing stairs. It can also be caused by a sudden change in physical activity. This change can be in the frequency of activity—such as increasing the number of days you exercise each week. It can also be in the duration or intensity of activity—such as running longer distances.
Use of improper sports training techniques or equipment
Changes in footwear or playing surface
Patellar Malalignment
Patellofemoral pain syndrome can also be caused by abnormal tracking of the kneecap in the trochlear groove.
In this condition, the patella is pushed out to one side of the groove when the knee is bent. This abnormality may cause increased pressure between the back of the patella and the trochlea, irritating soft tissues.
Factors that contribute to poor tracking of the kneecap include:
Problems with the alignment of the legs between the hips and the ankles. Problems in alignment may result in a kneecap that shifts too far toward the outside or inside of the leg, or one that rides too high in the trochlear groove—a condition called patella alta.
Muscular imbalances or weaknesses, especially in the quadriceps muscles at the front of the thigh. When the knee bends and straightens, the quadriceps muscles and quadriceps tendon help to keep the kneecap within the trochlear groove. Weak or imbalanced quadriceps can cause poor tracking of the kneecap within the groove.

The most common symptom of PFPS is a dull, aching pain in the front of the knee.
This pain—which usually begins gradually and is frequently activity-related—may be present in one or both knees. Other common symptoms include:
Pain during exercise and activities that repeatedly bend the knee, such as climbing stairs, running, jumping, or squatting.
Pain on the front of the knee after sitting for a long period of time with your knees bent, such as one does in a movie theater or when riding on an airplane.
Pain related to a change in activity level or intensity, playing surface, or equipment.
Popping or crackling sounds in your knee when climbing stairs or when standing up after prolonged sitting.

Question 19

Patellofemoral Syndrome tests

Answer 19

Special Tests:
No specific test
Depending on the degrees of damage, multiple tests may be positive due to inflammation.
Clark’s
Apprehension Test
Bounce Home Test

OR NO TESTS ARE POSITIVE

Question 20

Osgood-Schlatter Disease/Syndrome

Answer 20

Definition:
A condition that primarily affects adolescents, particularly those who are going through a growth spurt.
It is characterized by inflammation of the patellar ligament, which connects the kneecap (patella) to the shinbone (tibia).
This inflammation leads to pain and swelling in the area just below the kneecap.

Causes
Age and Gender:
Osgood-Schlatter disease typically occurs in adolescents between the ages of 10 and 15, during periods of rapid growth. It is more common in boys than in girls.
Physical Activity:
The condition is often associated with activities that involve running, jumping, and rapid changes in direction, such as those seen in sports like soccer, basketball, and gymnastics.

Symptoms

The main symptom is
pain and swelling just below the kneecap.
The pain may worsen during activities that involve bending or straightening the knee, such as running or climbing stairs.
The affected area may also be tender to touch.
Bony Bump:
In some cases, a bony bump or prominence may develop at the site of the inflammation.
This is an overgrowth of bone caused by the constant pulling of the patellar ligament on the developing bone.

FYI
The exact cause of Osgood-Schlatter disease is not fully understood, but it is believed to be related to the stress placed on the growing bones and the developing patellar ligament during periods of rapid growth. The repeated stress and strain can lead to inflammation at the site where the patellar ligament attaches to the shinbone.

Question 21

Osgood-Schlatter Disease tests

Answer 21

Special Tests:
No specific test
Just signs and symptoms

Question 22

Medial Tibial Stress Syndrome (MTSS) or Shin Splints

Answer 22

Definition:
A common condition characterized by pain along the inner edge of the shinbone (tibia).
This condition often occurs in individuals who engage in repetitive, high-impact activities, particularly those
involving running or jumping. Shin splints are not a specific medical diagnosis but rather a term used to describe a variety of lower leg pain symptoms.

Causes
The exact cause of shin splints is not always clear, but it is believed to result from
overuse or repetitive stress on the shinbone and the tissues attaching the shinbone to the muscles.
Factors such as flat feet, improper footwear, and training errors (such as overtraining or sudden increases in intensity) may contribute to the development of shin splints.

Symptoms
Pain is the primary symptom
along the inner edge of the shinbone, typically between the knee and ankle.
The pain may be diffuse or concentrated in a specific area and is often described as a dull, aching discomfort.
Shin splints are commonly associated with activities that involve running, jumping, or other high-impact exercises. They often occur in athletes or individuals who suddenly increase the intensity, duration, or frequency of their workouts.

Question 23

Medial Tibial Stress Syndrome (MTSS) or Shin Splints tests

Answer 23

Special Tests:
No specific test
Just signs and symptoms
Imaging