Rad Positioning (Lower Leg & Knee) 10-27-25

Which bone of the lower leg supports the weight of the body?

Tibia

Which bone transfers weight from the femur to the foot?

Tibia

Which condyle of the femur extends more distal?

Medial condyle

Which condyle of the femur extends more anterior?

Lateral condyle

When positioning for a lateral knee what angle is needed to superimpose the femoral condyles?

5-7° cephalic angle

What bones form the knee joint?

Femur and tibia

Does the fibula help form the knee joint?

No

Does the patella form part of the knee joint?

No

What is the name of the cartilage that rests on the tibial plateau and helps cushion the femur and tibia?

Meniscus

What are the two types of menisci found in the knee?

Medial and lateral meniscus

The articular facets that make up the tibial plateau slope posteriorly at what angle?

10-20°

The femur sits at what angle off of vertical?

5-15° (greater in females)

Another term for the patellar surface of the distal femur is what?

Intercondylar sulcus (or trochlear groove)

What type of joint is the knee classified as?

Bicondylar diarthrodial joint

What type of joint is the patellofemoral joint classified as?

Sellar or saddle joint

Which direction does the patella move when the knee flexes?

Inferiorly (downward)

Which direction does the patella most commonly dislocate?

Laterally

When the knee flexes what happens to the patella in relation to the femur?

It is drawn down into the patellar surface (sulcus)

Which structure acts as a shock absorber in the knee joint?

Meniscus

What is the posterior surface of the distal femur called?

Popliteal surface

Which femoral condyle sits slightly lower or more distal?

Medial condyle

Which femoral condyle sits slightly more anterior?

Lateral condyle

Which structure is only visible on a mispositioned lateral knee?

Adductor tubercle

Where is the adductor tubercle located?

On the posterior surface of the medial condyle of the femur

Which bone contains the tibial plateau?

Tibia

Which bone contains the lateral malleolus?

Fibula

Which bone contains the lateral epicondyle?

Distal femur

Which bone contains the plafond (distal articular surface)?

Tibia

What is the top portion of the patella called?

Base

What is the pointy lower portion of the patella called?

Apex

Which joint classification describes the proximal tibiofibular joint?

Plane (gliding) joint

Which joint classification describes the distal tibiofibular joint?

Amphiarthrodial syndesmosis

What term describes the large fossa between the femoral condyles?

Intercondylar fossa

What structure separates the femoral condyles on the tibia?

Intercondyloid eminence (tibial spine)

The superior articular surface of the tibia is called what?

Tibial plateau

When the leg is fully extended where is the patella located relative to the knee joint?

About ½ inch superior to the knee joint

What is the rough anterior ridge of the tibia called?

Anterior crest (shin)

What bony prominence on the tibia serves as a tendon attachment site?

Tibial tuberosity

What condition occurs when the tibial tuberosity separates in children or athletes?

Osgood-Schlatter's disease

The articular surface of the tibia has two facets which creates what?

Tibial plateau

In a well positioned lateral knee what two structures should be superimposed?

Medial and lateral femoral condyles

What bone do these belong to?

Femur

What structure from the previous two question will be visible if a lateral knee is mispositioned and what structure is it found on?

Adductor tubercle found on the medial condyle of the femur

The knee joint is formed from the tibia, femur, and fibula.

False

The ankle joint is formed from the tibia, fibula, and talus.

True

The most superior portion of the patella is the apex.

False

A wider pelvis will result in a more exaggerated angle off of vertical in the femur.

True

The adductor tubercle is only seen in a mispositioned lateral knee.

True

When the knee is flexed the patella will be pulled down into its sulcus.

True

What is the posterior slope of the tibial plateau?

10-20°

Which structure acts as a shock absorber for the knee joint?

Meniscus

Which bone contains the lateral epicondyle?

Distal femur

Which bone contains the lateral malleolus?

Fibula

Which bone contains the plafond?

Tibia

The base is found on which bone of the lower limb?

Patella

What views are required for a lower leg routine?

AP and lateral (must include both joints)

For an acute knee injury what routine is used?

4 view (AP, both obliques, cross-table lateral)

What is included in the 4V ortho routine?

AP and lateral standing of affected knee, bilateral Rosenberg, and axial patella

When is the Rosenberg replaced by the intercondyloid fossa view?

When performing the ortho routine on pediatric patients

Which bone of the lower leg is weight-bearing?

Tibia

Which side of the lower leg is the tibia on?

Medial

Which bones form the knee joint?

Femur and tibia

What is the intercondyloid eminence also called?

Tibial spine

What two parts make up the tibial spine?

Medial and lateral intercondyloid tubercles

What are the two condyles of the tibia?

Medial and lateral condyles

What structure forms the articular surface on top of the tibia?

Tibial plateau

What does the tibial plateau articulate with?

Femoral condyles

What structure serves as a tendon attachment on the anterior tibia?

Tibial tuberosity

What condition results when the tibial tuberosity separates from the tibia?

Osgood-Schlatter's disease

What ridge continues from the tibial tuberosity to the medial malleolus?

Anterior crest (shin)

Which view best shows the anterior crest?

Lateral view

What depression on the tibia articulates with the fibula?

Fibular notch

What forms the distal tib-fib joint?

Fibular notch of tibia and distal fibula

Name the distal tibial structures

Medial malleolus, anterior tubercle, posterior malleolus

What is the purpose of the fibula?

Serves as a brace for the tibia and helps form the ankle joint

Is the fibula involved in the knee joint?

No

Where is the fibula located?

Lateral side of the lower leg

What is the uppermost prominent area of the fibula?

Apex (styloid process)

What is the wide expanded proximal end of the fibula?

Head

What is the constricted area below the fibular head?

Neck

What is the distal end of the fibula called?

Lateral malleolus

What is the slope of the tibial plateau?

10-20° posterior

What angle compensates for the slope of the tibial plateau?

CR angled parallel to plateau (caudal for AP, cephalic for PA)

When would a CR angle adjustment be needed for a knee?

When the patient has thick or thin buttocks affecting femorotibial alignment

Which condyle of the tibia is medial?

The condyle on the same side as the tibia

Which condyle of the tibia is lateral?

The one nearest the fibula

What is best seen in a lateral lower leg?

Anterior crest moving medially distally

Which bone is the longest and strongest in the body?

Femur

What is the normal angle of the femur from vertical?

5-15°

Why is the femoral angle greater in females?

Wider pelvis (for childbirth)

How does patient height affect the femoral angle?

Taller patients have a smaller angle

Where is the patella located when the leg is fully extended?

½ inch superior to the knee joint

What is the anterior surface of the distal femur called?

Patellar surface

What are two other names for the patellar surface?

Intercondylar sulcus and trochlear groove

As the knee flexes what happens to the patella?

It moves distally over the patellar surface

What is found on the posterior distal femur?

Medial and lateral condyles

What lies between the femoral condyles?

Intercondylar fossa (ICF)

What structures are found above the condyles?

Medial and lateral epicondyles (palpable)

What raised area is found on the posterior aspect of the medial condyle?

Adductor tubercle

When is the adductor tubercle visible?

On a mispositioned lateral knee