Knee Disorders (Part 2)

PCL tears can also occur due to a high energy hyperextension injury. In this situation the ____ would rupture first and then if forceful enough the ____ would rupture. This type of injury would result in a complete disarticulation of the knee. (A medical emergency!!) (*Could compromise vital arteries of the LE*)

ACL / PCL

Forces translated across the patellofemoral joint can be __ times greater than bodyweight.

10

The Q-Angle in Women is typically <__ deg in extension &<__ deg at 90 deg of flexion. The Q-Angle in Men is typically <__deg in extension & <__ deg at 90 deg of flexion.

22 / 9 18 / 8

How long do you treat everything in ortho?

4-6 weeks

How do you treat meniscal tears as a result of an acute injury?

Arthroscopic surgery. - Partial menisectomy or meniscal repair.

How do you treat patellofemoral instability & malalignment with prior history of a dislocation?

Arthroscopy with lateral release and possible medial patellofemoral ligament repair

___________ meniscal tears often result in a "locked knee" because the tear becomes incarcerated within the joint.

Bucket-handle (Note: locking of the knee is NOT exclusive to meniscal tears)

What type of imaging is used in preoperative planning of the knee?

CT

What are some things you need to *rule out* before diagnosing someone with a gastrocnemius tear or strain?

Compartment Syndrome Medial meniscal tear DVT

What should you always rule out before diagnosing someone with a popliteal cyst?

DVT!

Why do we worry about patellofemoral instability & malalignment?

It ultimately results in subluxation or chronic dislocation causing degenerative changes in the joint.

What is theatre sign?

Knee pain that increases with prolonged sitting.

The __________ meniscus is "O-Shaped" and bears 70% of the contact pressure.

Lateral (I know the math doesn't add up....)

A patient presents to the clinic after an acute knee injury. She claims she was trying to make a cut while playing a game of soccer and her knee *twisted*. PE reveals *pain with palpation over the lateral joint line*, palpable clicking, and a *+ McMurray's Test*. What is your diagnosis?

Lateral Meniscal Tear

Gold standard for the diagnosis of a meniscal tear?

MRI = gold standard...although not necessary

With stress fractures a XR should be done initially but they are usually normal. A _____ or _____ is needed to evaluate for stress reactions and/or stress fractures.

MRI or bone scan

In addition to a arthroscopy with lateral release and possible medial patellofemoral ligament repair what else might be required to treat a patient for malalignment?

May require a tibial tubercle realignment

The __________ meniscus is "C-Shaped" and bears 50% of the contact pressure.

Medial

The _________ & _______________ are fibrocartilaginous pads responsible for shock absorption and to provide stability.

Medial & Lateral Menisci

A patient reports to the clinic with a complaint of acute calf pain. They describe a *"pulling or tearing" sensation* and their *pain is located posteromedial and proximal*. When you observe their gait you note *difficulty with the toe-off phase* and when you ask the patient they are unable to perform a *single leg heel raise*.

Medial Gastrocnemius Tear

*Which head of the gastrocnemius is most commonly torn?*

Medial head

A patient *greater than 40 yoa* reports to the clinic with a knee pain. He reports sustaining a direct blow to the patella and hearing a pop. Upon PE you note a *patella baja*, hemarthrosis, and *no active knee extension or straight leg raise*. What is your diagnosis?

Quad Tendon Rupture (Patella baja = low-riding patella)

T/F: Posteriomedial Stress Syndrome (Shin Splints) is a diagnosis of exclusion.

True

T/F: Meniscal tears most often occur occur in conjunction with ligamentous tears.

True, but they can also be isolated incidents.

Large popliteal cysts may ______ into the _____ and rupture.

dissect / calf

Meniscal tears can lead to mechanical derangement of the joint and ultimately _________.

early OA

Patellofemoral instability & malalignment usually occurs *(medially/laterally)* and is more common in *(men/women)*.

laterally / young women (Q angle)

What is the origin and insertion of the PCL?

medial intercondylar wall of the femur and posterior aspect of the tibia

Proximal gastrocnemius tears are often confused with a_______________.

medial meniscal tear

*Gastrocnemius tears typically occur at the ________________.*

musculotendinous junction

Stress fractures are caused by repetitive trauma which causes increased __________ activity, thus resulting in a stress reaction and ultimately stress fracture if left untreated.

osteoclastic

Patellar & Quad Tendon Rupture can occur in conjunction with _____________ or _____________________. (Mechanism of injury)

patellar fractures or a direct blow to the patella

Patellofemoral Pain Syndrome (PFPS) is thought to occur more often in women because of their broader ______ and a wider _________.

pelvis / wider Q-Angle

The PCL prevents ________ translation of the _____ over the _______.

posterior translation of the tibia over the femur (Think about what your trying to do in the posterior drawer test!)

What should you always rule out with Posteriomedial Stress Syndrome (Shin Splints)?

stress fracture or exertional compartment syndrome.

The pain in the patellofemoral pain syndrome is a result of the inflammation of the _________.

synovium

Why do we treat 1st time patella dislocations with PT?

vastus medialis oblique strengthening to stabilize the knee!

Where does osteonecrosis of the femoral condyle typically occur?

weight-bearing surface of the medial femoral condyle

Stress fractures normally get ____ with activity and better with _____.

worse / rest

How do we normally treat kids with OCD?

1. When overlying cartilage is intact may be treated non-operatively (For the skeletally immature) 2. Modify activities. LOW IMPACT

How would you treat a meniscal tear in an older patient w/ chronic degenerative changes or as a result of OA? (5)

(Conservative for these cases! Acute injuries usually require surgical repair) 1. Steroid injections 2. NSAIDS 3. Shoes 4. Orthotics with wedging 5. Unloader braces

What ligament is commonly torn in a patellar dislocation?

*Medial patellofemoral ligament* (MPFL) and retinacular tissue

Patient reports to the clinic with a suspected meniscal tear. Mechanism of injury involved *twisting of the knee*. They have *pain over the joint line*, effusion, and a *+ McMurray with a palpable click/pain*. A MRI reveals a *tear of the outer 1/3 of the meniscus*. How will you treat it?

*Meniscal Repair*

In what type of injury do *symptoms tend to "wax and wane"* which causes the patient to deal with or ignore them?

*Meniscal Tear*

Patient reports to the clinic with a suspected acute meniscal tear. Mechanism of injury involved *twisting of the knee*. They have *pain over the joint line*, effusion, and a *+ McMurray with a palpable click/pain*. A MRI reveals a *tear of the inner 2/3 of the meniscus*. How will you treat it?

*Menisectomy*

_____________ usually occur due to a forceful contraction of the quadriceps muscle group and a eccentric load placed on the knee.

*Patellar & Quad Tendon Rupture* (can also possibly be caused by a history of chronic tendinitis causing degenerative changes in the tendon)

How do you treat plica syndrome?

*Same as patellofemoral + Arthroscopy with plica excision* 1. Activity modification 2. *PT = VMO strengthening* 3. Orthotics 4. Good shoes...*NO HEELS!* 5. NSAIDS 6. Steroid injection 7. Arthroscopy

Patients with Posteriomedial Stress Syndrome (Shin Splints) have _________ tenderness over the _____ of the ________. Whereas patients with stress fractures typically have ________ tenderness.

*diffuse* / distal third of the tibia / *point*

Acute meniscal tears usually occur due to a ________ type of injury. Whereas chronic degenerative tears usually occur in older pts with little to no trauma.

*twisting*

What are some physical exam findings of patellofemoral instability & malalignment? (5)

1. + Apprehension test 2. Patella gliding laterally (Common with femoral anteversion and Genu valgum) 3. Hypermobility of patella (over ½ the width of patella) 4. +J sign 5. Pain along anteromedial patellofemoral joint = torn medial patellofemoral ligament/retinaculum

How do you treat patellofemoral pain syndrome?

1. Activity modification 2. *PT = vastus medialis oblique strengthening* 3. Orthotics 4. Good shoes...*NO HEELS!* 5. NSAIDS 6. Steroid injection 7. Arthroscopy

How do you treat a popliteal (Baker's) cyst? (3)

1. Aspiration (Wouldn't suggest this unless trained. Nerves and vessels mostly medial, so *aim for the lateral side*.) 2. Cyst excision...rare. (Stupid, it will just grow back) 3. *Treat underlying problem*

What are the three common mechanisms of injury for a PCL tear?

1. Dashboard injury/MVA 2. Fall on flexed knee w/ foot plantarflexed 3. Hyperflexion of knee

How do you treat patellofemoral instability & malalignment with *no prior history of dislocations*?

1. Reduction (If dislocated...) 2. Patella-stabilizing brace 3. NSAIDS 4. PT

1. What type of imaging is best to evaluate for patellar dislocations? 2.What is best for chronic instability?

1. Sunrise View X-Ray 2. MRI (will often show chondral defects over lateral femoral condyle and patella)

What are some types of distal femur fractures?

1. Supracondylar 2. Medial femoral condyle 3. Lateral femoral condyle (Only 4-7% of femur fractures are distal fractures)

*What are the three distinct plica and what is the primary plica that is symptomatic?*

1. Suprapatellar Plica 2. *Medial (Shelf) Plica* (Most commonly Symptomatic) 3. Infrapatellar Plica

What are some causes of osteonecrosis of the femoral condyle? (5)

1. Trauma 2. Idiopathic 3. Chronic steroid use 4. SLE 5. Sickle cell anemia

How do we treat osteonecrosis of the femoral condyle? (6)

1. Unloader brace (also for meniscal tear) 2. Orthotics 3. NSAIDS 4. Steroid injections 5. Arthroscopy with chondroplasty/microfracture 6. TKA

T/F: Osteonecrosis of the femoral condyle is usually due to degenerative changes of the bone.

False usually due to trauma (occurs more often in women >60 yoa)

T/F: Meniscal tears are only caused by acute injuries.

False, they can also be caused by chronic degenerative changes.

How do you treat shin splints?

Good shoes, orthotics, PT Consider running surface If patient continues to return +/- MRI or bone scan to rule out stress fracture.

How do you treat a gastrocnemius tear? (5)

NSAIDS Rest Ice PT Possible cam walker or splint.

How do we treat non-displaced/minimally displaced fractures vs. displaced fractures?

No/Minimal Displacement: Conservative Treatment Displaced: ORIF

A 11 year old female presents to the clinic with a complaint of *insidious onset knee pain*. She describes a history of catching and locking. PE reveals joint effusion, pain over the joint line, and a *+ Wilsons Test*. What is your diagnosis?

Osteochondritis Disssecans (OCD)

______________ is the osteonecrosis or avascular necrosis of the subchondral bone caused by repetitive small stresses or trauma, disrupting blood supply thus bone death. Ultimately, dead bone separates from living bone via fibrous healing. Over time the dead bone causes the area to become weak and shear forces cause the articular cartilage to weaken and pull off the surface of the joint forming a "loose body".

Osteochondritis Disssecans (OCD)

What is the strongest ligament of the knee?

PCL

A patient reports to the ER with a complaint of knee pain. The patient states he flipped off of his skateboard and fell with all of his weight onto his flexed right knee and heard a pop. PE reveals effusion, + posterior drawer, and + Thumb Sign (Sag sign). What is your diagnosis?

PCL tear

A patient *greater than 40 yoa* reports to the clinic with knee pain. He reports sustaining a direct blow to the patella and hearing a pop. Upon PE you note a *patella alta*, hemarthrosis, and *no active knee extension or straight leg raise*. What is your diagnosis?

Patellar Tendon Rupture (Patella alta = high-riding patella)

_____________ refers to a host of problems revolving around diffuse anterior knee pain induced by activities that load the patellofemoral joint (running, stairs, squatting, and kneeling.)

Patellofemoral Pain Syndrome (AKA patellofemoral joint syndrome or chondromalacia patellae)

A patient reports to the clinic with a chief complaint of knee pain. Her pain is located over the anterior knee and it fluctuates between an ache and a sharp pain. Aggravating factors include prolonged sitting, climbing stairs, jumping, and squatting. She also reports *retropatellar clicking* and crepitus. Upon PE you note *genu valgum, vastus medialis oblique atrophy, hamstring/quad tightness, and a + grind test*. What is your diagnosis?

Patellofemoral Pain Syndrome (PFPS)

Posteriomedial Stress Syndrome (Shin Splints) usually develops in response to running or some type of exercise. It is the result of a inflamed ________ secondary to chronic stress from the attached muscles.

Periosteum

A _______ is an extension or fold in the synovial capsule of the knee.

Plica

A patient presents to the clinic with *insidious onset knee pain* described as an *ache or a sharp pain*. The patient also reports a *painful popping or snapping* of the knee and a *sense of instability*. PE reveals a taut articular band that reproduces the patient's pain upon palpation. Apprehension and grind test are negative. What is your diagnosis?

Plica Syndrome

Describe the pathophysiology of plica syndrome.

Plica are extensions of the synovium that can become inflamed as a result of injury or overuse and subsequently thicken in the joint cavity. The plica can "bowstring" over the femoral condyle or patella which can cause a chondral defect and pain.

____________ is found in the popliteal fossa and is the result of a distended semimembranosus or medial gastrocnemius bursa. It is caused by any intraarticular pathology that results in a effusion of the knee (such as OA). The distended bursa forms a communication with the joint cavity, this communication acts as a valve forcing fluid from the joint into this structure. The size of this structure will often fluctuate and causes the patient pain.

Popliteal Cyst (AKA Baker's Cyst)

____________ are thought to be an overuse injury characterized by insidious onset of posteromedial tibial pain.

Posteriomedial Stress Syndrome (Shin Splints)

A young woman present to the ER stating she broke her knee. She describes hearing a loud pop while jumping and the *lateral displacement of her kneecap*. After walking for a minute her kneecap reduced but she still has pain, and now her knee is swollen. What is the most likely explanation for this series of events?

Subluxation or dislocation of the patella due to patellofemoral instability & malalignment

How do you treat a Patellar Tendon or Quad Tendon Rupture? (3)

Surgery Partial tears could be treated with immobilization 4-6 wks., then PT. REFER

Treatment options for adults with OCD?

Surgical intervention is usually reserved for the *skeletally mature* patient when there is *disruption of the articular cartilage.* 1. Internal fixation 2. Osteochondral allograft vs. autograft 3. Microfracture 4. REFER

T/F: PCL tears are usually treated non-operatively.

TRUE! Treatment focus is on PT and quad training, bracing may be used. BUT.... PCL Reconstruction is indicated for a active person with continued symptoms of instability, etc. (Graft selection same as ACL)

Why does the location of a mensical tear determine whether to do a partial menisectomy vs. a meniscal repair?

Tears over the *inner 2/3 occur in an avascular zone*, and thus require a meniscectomy. The *outer 1/3 of the meniscus is vascular* due to capsular attachment therefore these tears can be repaired.

How do you perform the Wilson Test?

The examiner flexes the knee to 90° while internally rotating the tibia. A positive Wilson sign occurs when pain is elicited at 30° of flexion and is relieved with external rotation. (Pain occurs due to the tibial spine touching the medial condyle or OCD lesion therefore rotating it away relieves their pain)

*Where does Osteochondritis Disssecans (OCD) of the knee most commonly occur*

The lateral aspect of the medial femoral condyle