Courtesy of vulture.com
Differential Diagnoses
Listed below are some of the common injuries/conditions associated with the knee complex
MCL sprain
What is it? The Medial Collateral Ligament is the knee ligament located on the inner side of the knee joint. It links the thigh bone and the shin bone. The Medial Collateral Ligament is the large ligament on the inside of the knee that links the thigh bone and the shin bone. Damage to a ligament is referred to as a sprain, and depending on the severity of the injury it is classified as first, second or third degree:
nt there will be pain when the site of the damage is touched. Stressing the ligament (when the knee is slightly bent and the shin is moved inwards in relation to the thigh) is painful - this action is reproduced when standing up from sitting in a chair.
In the case of a second degree sprain, the pain is more severe when touched and when the ligament is stressed. There will usually be a swelling of the knee joint, but this may take 24 hours to appear.
In the case of a third degree sprain, where the ligament is ruptured, the knee joint is unstable and activity cannot be continued. There will be a bleed and an inflow of fluid into the joint but, because the capsule that surrounds the joint is also damaged, this fluid may leak out and swelling may not be evident
MOI: A knee ligament injury is referred to as a sprain, and this knee injury can occur if the knee is twisted or subject to force from an opponent during sport. The injury is usually caused in one of two classic ways. In collision sports such as football (soccer), rugby, and American football, the Medial ligament can be damaged when an opponent applies a force (usually from their knee) to the outside aspect of the leg, just above the knee. Alternatively the Medial ligament can be damaged if the studs get caught in turf and the player tries to turn to the side, away from the planted leg .
ACL sprain
What is it? A torn ACL is an injury or tear to the anterior cruciate ligament (ACL). The ACL is one of the four main stabilising ligaments of the knee, the others being the Posterior Cruciate Ligament (PCL), Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL). The ACL attaches to the knee end of the Femur (thigh bone), at the back of the joint and passes down through the knee joint to the front of the flat upper surface of the Tibia (shin bone).
Signs/Symptoms: There may be an audible pop or crack at the time of injury
PCL sprain
What is it? The incidence of injuries of the PCL is less than that of the anterior cruciate ligament. This is mainly due to the greater thickness and strength of the PCL. Nevertheless, the most common way in which the PCL is injured is by direct impact to the front of the tibia itself, usually when the knee is bent, PCL tears are graded I- III with III being the most severe. These gradings are classified depending on the amount of backward tibial displacement observed when the knee is bent at 90 degrees. In extreme cases the ligament may become avulsed, or pulled off the bone completely.
Signs/Symptoms: Pain at the time of impact which, over time, may also be felt in the calf region.
LCL Sprain
What is it? The lateral collateral ligament is a thin band of tissue running along the outside of the knee. It connects the thighbone (femur) to the fibula, which is the small bone of the lower leg that turns down the side of the knee and connects to the ankle. Like the medial collateral ligament, the lateral collateral ligaments main function is to keep the knee stable as it moves through its full arc of motion.
Signs/Symptoms:
The ligament can also be injured by repeated stress that causes it to lose its normal elasticity. Most knee injuries are to the ligaments that support the knee, not the knee joint itself.
Meniscus Tear (Medial)
What is it? A tear in the medial meniscus that lies between the femur and tibia
Signs/Symptoms
Meniscus Tear (Lateral)
What is it? A tear in the lateral meniscus that lies between the Femur and Tibia
Signs/Symptoms:
Chondromalacia
What is it? Softening and subsequent wearing away of the patella’s hyaline cartilage
Signs/Symptoms
Patellar Tendonitis
What is it? Inflammation of the patellar tendon
Signs/Symptoms:
Patellar Tendinosis
What is it? A breakdown of the collagen in the tendons.
Sign/Symptoms:
MOI: Overuse injury
Patellar Tenosynovitis:
What is it? Inflammation of the synovial membrane surrounding the tendon.
Signs/Symptoms:
Fractured Patella
What is it? A break in the Patella
Signs/Symptoms:
Hyperextended Knee
What is it? Damage to the ligaments, cartilage, or other supportive structures surrounding the knee.
Signs/Symptoms:
Distal Hamstring Strain
What is it? A pull or tear of the distal hamstrings.
Signs/Symptoms:
Patellar Dislocation/Subluxation
What is it? Mal-alignment of the Patella.
Signs/Symptoms:
Patellar Tendon Rupture
What is it? A rupture to the patellar tendon which connect the Patella and Tibia
Signs/Symptoms:
Peroneal Nerve Contusion
What is it? Bruising around the peroneal nerve.
Signs/Symptoms:
Tibial Torsion
What is it? Inward twisting of the Tibia
Signs/Symptoms:
Fabella Syndrome
What is it? Friction of the Fabella on the posterior lateral condyle.
Signs/Symptoms:
Pre-Patellar Bursitis
What is it? Inflammation of the bursa that allows the patella to move freely beneath the skin
Signs/Symptoms:
Synovial Plica
What is it? Inflammation of the protective synovial capsule of the knee
Signs/Symptoms:
Osgood Schlatter disease
What is it? Osgood-Schlatter (OS) disease is one of the most common causes of knee pain in the adolescent. Consisting of pain and edema of the tibial tubercle (and hence this is an extra-articular disease)
Signs/Symptoms: Pain is the most common presenting complaint.
Patellofemoral Joint Pain (Runner's Knee):
What is it? Patella Femoral Syndrome is a common knee injury among athletes and active people. Also known as Patella Femoral Pain Syndrome and Patella Femoral Compression Syndrome, it is characterized by pain around the kneecap that increases with activities
Signs/Symptoms:
Baker's Cyst
What is it? A Baker's cyst is a condition in which you experience a bulge and a feeling of tightness behind your knee. The pain gets worse when you fully extend your knee or when you're active.
Signs/Symptoms: In some cases, a Baker's cyst causes no pain and may go unnoticed. If you do experience signs and symptoms, you may notice:
Osteochondritis Dissicans
What is it? When blood supply to the area at the end of your bone is cut off, a condition known as osteochondritis dissecans may develop. The affected bone and its covering of cartilage may stay in place and cause no symptoms. Or, a fragment may gradually loosen, separate and cause pain.
Signs/Symptoms:
· Restricted blood supply. An impaired blood supply to your bone (vascular insufficiency) also may play a role in the condition. The impaired supply is due to a slight blockage of a small artery and gradually can cause a breaking down or death of bone tissue (avascular necrosis).
· Your genetic makeup. Some people also may be genetically predisposed to develop osteochondritis dissecans.
Iliotibial Band Friction Syndrome
What is it? It is a condition characterized by pain localized over the lateral femoral epicondyle that occurs during vigorous walking, hiking or running. The pain is usually relieved by rest and by walking with the knee held in full extension. However, when ambulation and knee flexion are resumed, symptoms return.
Signs/Symptoms:
Anteromedial Rotary Instability
What is it? An instability within the knee joint which pertains to rotational and medial movements.
Signs/Symptoms:
Anterolateral Rotary Instability
What is it? An instability within the knee joint which pertains to rotation and lateral movements.
Signs/Symptoms:
Capsular Contusion
What is it? Bruise to the soft tissue surrounding the knee joint.
Signs/Symptoms:
Fat Pad Contusion
What is it? Bruise to the fat pad located inferior to the Patella.
Signs/Symptoms:
MCL sprain
What is it? The Medial Collateral Ligament is the knee ligament located on the inner side of the knee joint. It links the thigh bone and the shin bone. The Medial Collateral Ligament is the large ligament on the inside of the knee that links the thigh bone and the shin bone. Damage to a ligament is referred to as a sprain, and depending on the severity of the injury it is classified as first, second or third degree:
- A first degree sprain is damage to only a few ligament fibers.
- A second degree sprain is damage to a more extensive number of ligament fibres, but the ligament remains intact.
- A third degree sprain is a complete rupture of the ligament. Because of the force involved in this injury other structures in the knee, such as the Meniscus (Cartilage) or the Anterior Cruciate Ligament can also be damaged.
nt there will be pain when the site of the damage is touched. Stressing the ligament (when the knee is slightly bent and the shin is moved inwards in relation to the thigh) is painful - this action is reproduced when standing up from sitting in a chair.
In the case of a second degree sprain, the pain is more severe when touched and when the ligament is stressed. There will usually be a swelling of the knee joint, but this may take 24 hours to appear.
In the case of a third degree sprain, where the ligament is ruptured, the knee joint is unstable and activity cannot be continued. There will be a bleed and an inflow of fluid into the joint but, because the capsule that surrounds the joint is also damaged, this fluid may leak out and swelling may not be evident
MOI: A knee ligament injury is referred to as a sprain, and this knee injury can occur if the knee is twisted or subject to force from an opponent during sport. The injury is usually caused in one of two classic ways. In collision sports such as football (soccer), rugby, and American football, the Medial ligament can be damaged when an opponent applies a force (usually from their knee) to the outside aspect of the leg, just above the knee. Alternatively the Medial ligament can be damaged if the studs get caught in turf and the player tries to turn to the side, away from the planted leg .
ACL sprain
What is it? A torn ACL is an injury or tear to the anterior cruciate ligament (ACL). The ACL is one of the four main stabilising ligaments of the knee, the others being the Posterior Cruciate Ligament (PCL), Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL). The ACL attaches to the knee end of the Femur (thigh bone), at the back of the joint and passes down through the knee joint to the front of the flat upper surface of the Tibia (shin bone).
Signs/Symptoms: There may be an audible pop or crack at the time of injury
- A feeling of initial instability, may be masked later by extensive swelling.
- A torn ACL is extremely painful, in particular immediately after sustaining the injury.
- Swelling of the knee, usually immediate and extensive, but can be minimal or delayed.
- Restricted movement, especially an inability to fully straighten the leg
- Possible widespread mild tenderness
- Positive signs in the anterior drawer test and Lachman's test.
- Tenderness at the medial side of the joint which may indicate cartilage injury.
PCL sprain
What is it? The incidence of injuries of the PCL is less than that of the anterior cruciate ligament. This is mainly due to the greater thickness and strength of the PCL. Nevertheless, the most common way in which the PCL is injured is by direct impact to the front of the tibia itself, usually when the knee is bent, PCL tears are graded I- III with III being the most severe. These gradings are classified depending on the amount of backward tibial displacement observed when the knee is bent at 90 degrees. In extreme cases the ligament may become avulsed, or pulled off the bone completely.
Signs/Symptoms: Pain at the time of impact which, over time, may also be felt in the calf region.
- Swelling, although this may be minimal
- Pain when the posterior cruciate ligament is stressed
- Positive sign on the 'Posterior draw test'.
- Pain and laxity when a 'reverse Lachman's test' is performed.
- Instability of the joint, perhaps associated with the feeling of the knee 'giving way.
LCL Sprain
What is it? The lateral collateral ligament is a thin band of tissue running along the outside of the knee. It connects the thighbone (femur) to the fibula, which is the small bone of the lower leg that turns down the side of the knee and connects to the ankle. Like the medial collateral ligament, the lateral collateral ligaments main function is to keep the knee stable as it moves through its full arc of motion.
Signs/Symptoms:
- A feeling that the knee may give way under stress and isn't stable
- A locking or catching in the joint when it is moved
- Numbness or weakness in the foot that may occur in the peroneal nerve, which is near the ligament stretched during the injury or is pressed by swelling in surrounding tissues
- Pain that can be mild or acute
- Stiffness
- Swelling and tenderness along the outside of the knee
The ligament can also be injured by repeated stress that causes it to lose its normal elasticity. Most knee injuries are to the ligaments that support the knee, not the knee joint itself.
Meniscus Tear (Medial)
What is it? A tear in the medial meniscus that lies between the femur and tibia
Signs/Symptoms
- Knee pain
- Limited motion
- Swelling
- Tenderness
- Popping/click sound
Meniscus Tear (Lateral)
What is it? A tear in the lateral meniscus that lies between the Femur and Tibia
Signs/Symptoms:
- Knee pain
- Limited motion
- Swelling
- Tenderness
- Popping/click sound
Chondromalacia
What is it? Softening and subsequent wearing away of the patella’s hyaline cartilage
Signs/Symptoms
- Knee pain
- Stiffness
- Grinding sensation
- Swelling
- Joint feel warm to touch
- Redness around joint
Patellar Tendonitis
What is it? Inflammation of the patellar tendon
Signs/Symptoms:
- Swelling
- Pain associated with knee movement
- Inflammation
Patellar Tendinosis
What is it? A breakdown of the collagen in the tendons.
Sign/Symptoms:
- Swelling
- Pain associated with knee movement
- Inflammation
MOI: Overuse injury
Patellar Tenosynovitis:
What is it? Inflammation of the synovial membrane surrounding the tendon.
Signs/Symptoms:
- Swelling
- Pain associated with knee movement
- Inflammation
Fractured Patella
What is it? A break in the Patella
Signs/Symptoms:
- Pain
- Bruising
- Inability to walk or straighten the knee
- Visible deformity
Hyperextended Knee
What is it? Damage to the ligaments, cartilage, or other supportive structures surrounding the knee.
Signs/Symptoms:
- Pain
- Visible deformity
Distal Hamstring Strain
What is it? A pull or tear of the distal hamstrings.
Signs/Symptoms:
- Pain
- Swelling
- Warm to the touch
- Inability to bear weight
Patellar Dislocation/Subluxation
What is it? Mal-alignment of the Patella.
Signs/Symptoms:
- Pain
- Apprehension
- Visible deformity
Patellar Tendon Rupture
What is it? A rupture to the patellar tendon which connect the Patella and Tibia
Signs/Symptoms:
- Pain
- Inflammation
- Inability to extend the knee
- Inability to bear weight
Peroneal Nerve Contusion
What is it? Bruising around the peroneal nerve.
Signs/Symptoms:
- Pain
- Swelling
- Numbness
- Tingling
Tibial Torsion
What is it? Inward twisting of the Tibia
Signs/Symptoms:
- A noticeable abnormality in gait
Fabella Syndrome
What is it? Friction of the Fabella on the posterior lateral condyle.
Signs/Symptoms:
- Slow, insidious pain
- Sharp, intermittent pain
- Localized tenderness
Pre-Patellar Bursitis
What is it? Inflammation of the bursa that allows the patella to move freely beneath the skin
Signs/Symptoms:
- Swelling over the kneecap
- Limited/painful movement of the knee
Synovial Plica
What is it? Inflammation of the protective synovial capsule of the knee
Signs/Symptoms:
- Swelling
- Pain associated with certain exercises
- Inflammation
Osgood Schlatter disease
What is it? Osgood-Schlatter (OS) disease is one of the most common causes of knee pain in the adolescent. Consisting of pain and edema of the tibial tubercle (and hence this is an extra-articular disease)
Signs/Symptoms: Pain is the most common presenting complaint.
- The pain may be reproduced by extending the knee against resistance, stressing the quadriceps, or squatting with the knee in full flexion.
- Running, jumping, kneeling, squatting, and ascending/descending stairs exacerbate the pain.
- Relief of symptoms occurs with rest or restriction of activities.
- Pain usually has been present intermittently for several months before the patient seeks medical care.
- The pain is bilateral in 25% of cases.
- Approximately 50% of patients give a history of precipitating trauma.
Patellofemoral Joint Pain (Runner's Knee):
What is it? Patella Femoral Syndrome is a common knee injury among athletes and active people. Also known as Patella Femoral Pain Syndrome and Patella Femoral Compression Syndrome, it is characterized by pain around the kneecap that increases with activities
Signs/Symptoms:
- Pain on the sides of the kneecap or under the Patella
- Grinding
Baker's Cyst
What is it? A Baker's cyst is a condition in which you experience a bulge and a feeling of tightness behind your knee. The pain gets worse when you fully extend your knee or when you're active.
Signs/Symptoms: In some cases, a Baker's cyst causes no pain and may go unnoticed. If you do experience signs and symptoms, you may notice:
- Swelling behind your knee, and sometimes in your leg
- Knee pain
- Stiffness
Osteochondritis Dissicans
What is it? When blood supply to the area at the end of your bone is cut off, a condition known as osteochondritis dissecans may develop. The affected bone and its covering of cartilage may stay in place and cause no symptoms. Or, a fragment may gradually loosen, separate and cause pain.
Signs/Symptoms:
- Pain
- A "locking" of your joint — the joint "sticks" and won't move through its full range of motion
- A feeling that your joint is "giving way" or weakening
- Decreased joint movement — an inability to straighten your leg or arm fully, or a limited range of motion
- Limping
- Swelling and tenderness of the skin over your joint
- Stiffness after resting
· Restricted blood supply. An impaired blood supply to your bone (vascular insufficiency) also may play a role in the condition. The impaired supply is due to a slight blockage of a small artery and gradually can cause a breaking down or death of bone tissue (avascular necrosis).
· Your genetic makeup. Some people also may be genetically predisposed to develop osteochondritis dissecans.
Iliotibial Band Friction Syndrome
What is it? It is a condition characterized by pain localized over the lateral femoral epicondyle that occurs during vigorous walking, hiking or running. The pain is usually relieved by rest and by walking with the knee held in full extension. However, when ambulation and knee flexion are resumed, symptoms return.
Signs/Symptoms:
- Pain localized over lateral femoral condyle
- Discomfort initially relieved by rest
- Pain may radiate toward the lateral joint line and proximal tibia
- Worse if a person continues to run
- No symptoms of internal derangement
- Symptoms frequently develop during downhill running
Anteromedial Rotary Instability
What is it? An instability within the knee joint which pertains to rotational and medial movements.
Signs/Symptoms:
- Pain
- Laxity
- Instability
Anterolateral Rotary Instability
What is it? An instability within the knee joint which pertains to rotation and lateral movements.
Signs/Symptoms:
- Pain
- Laxity
- Instability
Capsular Contusion
What is it? Bruise to the soft tissue surrounding the knee joint.
Signs/Symptoms:
- Pain
- Swelling
- Tenderness
- Bruising
Fat Pad Contusion
What is it? Bruise to the fat pad located inferior to the Patella.
Signs/Symptoms:
- Pain
- Swelling
- Tenderness
- Bruising
case scenario 1:
2a. Based on the overall Injury Evaluation of this individual, which of the above injuries/conditions would you consider as diagnoses?
Case scenario 2:
2b. Based on the overall Injury Evaluation of this individual, which of the above injuries/conditions can be ruled out as part of your differential diagnosis?