Exam 1 (wks 1-3) Flashcards by Amanda Ramos

What type of joint is the tibiofemoral joint, what motion does it prevent and how many degrees of freedom does it have?

Double condyloid
prevents motion in the frontal plane
2 degrees of freedom
- flex/ext in sagittal plane
- med/lat rotation in transverse plane

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What are 4 characteristics of the femoral articular surface?

1) Large AP convexity
2) Small curvature posterior
3) Medial condyle longer than lateral
4) Medial condyle extends further distally (for angled femur)

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What are 4 characteristics of the tibial articular surface?

1) Tibial plateaus are concave/ slope posterioinferiorly
2) Medial tibial plateau is 50% larger/ 3X thicker
3) Lateral plateau is more circular
4) menisci compensate for incongruence

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What are the functions of the menisci?

To increase stability by deepening tibial plateau
To increase contact area
To decrease friction
Enhance proprioception
Attenuate forces (50-60% of load at knee)

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3 characteristics of the medial meniscus

C-shaped
Firm attachment to deep layers of the MCL
Thick posteriorly

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3 characteristics of the lateral meniscus

O-shaped
Loose attachment to lateral capsule
Uniform thickness

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What is the role of the tibialfemoral ligaments?

Control/ resist:
- hyperextention
- varus/valgus stress
- AP displacement of tibia on femur
- combination of AP and rotation motions

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What does the MCL prevent

Abduction (valgus stress) and assists with preventing anterior tibial translation

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T/F the MCL and LCL are lax in flexion and taught in extension

True. Ligs offer most stability in knee extension

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T/F both the MCL and LCL have poor healing potential

False. They are well vascularized so they heal well.

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What are the origin and insertion of the ACL?

Origin = ant. aspect of tibia
Insertion = pos. aspect of lateral femoral condyle

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T/F the anteromedial bundle of the ACL is taught in ext and lax in flexion

False. (think pant leg)

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T/F the posterolateral bundle of the ACL is taught in ext and lax in flexion

True. (think pant leg)

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Define genu valgum

TF angle < 165 deg
Increased lateral compressive forces

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Define genu varum

TF angle > 180 deg
Increased medial compressive forces

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What is Q angle and do males of females typically have a greater Q angle?

Q angle = angle formed by line drawn from ASIS to mid-patella to tibial tuberosity
- Males 10-14 deg
- Femailes 15-17 deg

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What is genu recurvatum?

Excessive hyperextension (anything more than 10 deg)

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Decreased closed chain dorsiflexion causes what at the knee?

decreased knee flexion

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Decreased closed chain plantar flexion causes what at the knee?

decreased knee extension

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Describe the screw home mechanism

During the last 5 deg of extension
- lateral rot of tibia on femur (IR of femur)
- augmented by tension on ACL and lateral pull of quads

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Name 4 qualities of the PCL

Prevents post. translation of the tibia on femur
Gives minor restraint to varus/valgus stress
Shorter than ACL
Rarely injured (one of the strongest lig in the body)

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What is considered normal flexion and extension for the knee?

Flexion = 130-140 deg
Extension = 5- 10 deg of hyperextension

How much internal/external rotation is in the knee at 0 deg vs. 90 deg of flexion?

0 deg = restricted due to interlocking of femoral and tibial condyles

90 deg =
-ER: 0-45 deg
-IR: 0-30 deg

What role does the popliteas play in knee joint arthrokinematics?

It helps ‘unlock’ the knee.
OKC: moves tibia medially as knee flexes
CKC: moves femur laterally as knee flexes

When is the first consistent patellar femoral contact and at what various degrees of flexion do the different facets contact?

10-20 deg = first contact 90 deg = medial and lateral facets 135 = lateral and odd

What angle of knee flexion has the greatest compression forces on the patella?

90 deg

How much knee flexion do you need for the following activities? - Gait - on/off toilet - stair climbing - sit/raise chair - in/out bath - advanced function

Gait: 60-70 deg Toilet: 75 deg Stair climbing: 70-80 deg Sit/rise chair: 90 deg In/out bath: 90 deg Advanced function 115 deg

Neoplastic Disease

Most common in adolescents Persistent knee pain with no known cause Not easily reproduced during physical exam

Cellulitis

Fever, chills, malaise History of open wound More common in pt with venous insufficiency, congestive heart failure, or liver cirrhosis Tenderness, swelling, warmth, weakness

Reactive Arthritis

Constant aching or throbbing Reactive = infection somewhere else that has spread Septic = infection in the knee

Rheumatoid Arthritis

Pain an stiffness in more than 1 joint fever wt. loss bilateral symptoms

Gout

painful knee worse with activity tends to be chronic with intervals between attacks

Osteochondritis (OCD)

can occur in adults and children result of acute trauma or repetitive stress diagnosed via imaging Mild effusion Special tests negative

Acute compartment syndrome

6 Ps (pain, palor, pressure, paresthesia, pulselessness and paralysis Urgent refferal

Peripheral arterial occlusive disease (PAD)

lower extremity pain, cramping, numbness intermittent claudication age >60, hx of heart disease, type II diabetes sedentary, hx of smoking symptoms = shiny lower extremity, cold skin, decreased capillary refill

Superficial vein thrombosis

inflammation of superficial vein due to blood clot swelling, warmth, tenderness, may be hard red cord near surface of skin

Deep Vein Thrombosis

deep pain and cramping heart is racing dizziness coughing up blood *wells criteria

What structures are responsible for producing pain in patellarfemoral knee pain?

Soft tissues: synovial tissue retinaculum fat pad capsule

What are the 3 subgroups for patellarfemoral pain?

Strong Weak and tight Weak and pronated

What type of collagen are ligaments and what type are they replaced with when injured?

Type 1 = designed to resist tension Type 3 = scar tissue, not as strong

What are some negative effects of immobilization for more than 1-2 wks?

Lig. will atrophy decreased tensile strength boney attachments weaken 6 wks can lead to 50% loss of strength

Meniscus tear pathophysiology

Twisting injury Pain worse with movement better with rest Locking Joint line tenderness Acute effusion

Good prognosis for meniscus tear

Age < 35 Peripheral damage longitudinal tear short tear bloody effusion

Hallmark objective findings for meniscus tear

Joint line tenderness Effusion Positive entrapment test Quad inhibition

What do we need to be careful of when rehabing a meniscal repair?

Semembranosus inserts on the medial meniscus so avoid straining the hamstring. Don't push ROM

Grade 2 articular cartilage lesion

lesion extending down to < 50% of cartilage depth

Grade 3 articular cartilage lesion

Defect extending down to > 50% of cartilage depth. Down to but NOT through the subchondral bone

Signs of articular cartilage damage

Malalignments painful crepitus quad atrophy pain and swelling after use deep, dull ache

Who is microfracture treatment indicated for?

Less active more sedentary individuals

What is an ACI?

Autologous chondrocyte implantation Small biopsy of cartilage is harvested Digested to release chondrocytes Re implanted PROM is key

What is an OATS

Osteochondral autograft transplantation system Remove plug from NWB surface Fit into lesion PRPOM is key

Kellgren Lawrence Classification for Knee OA

Grade 2 = mild (definite osteophyte, normal joint space) Grade 3 = Moderate (joint space reductions) Grade 4 = Severe (joint space greatly reduced, subchondral sclerosis)

Patient presentation of OA

gradual onset, stiffness and crepitus Too much or too little activity hurts progressively worsens overtime Swelling Bony enlargement