Knee and Distal Femur

What is the longest, strongest, and heaviest bone in the body?

femur

Explain the shape of the femur

slightly convex anteriorly; slants medially 10-15^o, placing medial condyle lower than the lateral

Explain the location of the condyles of the femur

distal, rounded, non-palpable aspect of the bone

medial is larger and more inferior

Explain the location of the epicondyles of the femur

palpable prominences above the condyles

medial is larger

Explain the location of the adductor tubercle

non-palpable prominence on the superior posterolateral aspect of the medial epicondyle

Explain the intercondylar fossa/notch (location and what it is)

deep depression on the posterior distal surface of the femur between the condyles

Explain the linea aspera (location and what it is)

bony ridge on posterior femur that divides into the medial and lateral supracondylar lines

Explain the popliteal surface (location and what it is)

triangular surface superior to the intercondylar fossa on the posterior distal femur

margin formed by medial and lateral supracondylar lines

Where does the patella sit on the femur?

the patellar surface/intercondylar sulcus/trochlear groove

Which condyle of the femur has a more anterior projection (appears higher in sunrise view)?

lateral

What is osteoarthritis?

joint degeneration due to age; causes pain, stiffness, swelling, limited movement; treated by arthroplasty

Why should the leg be flexed only 20-30^o for a lateral knee?

to open the patellofemoral joint space as much as possible

Why is a 5-7^o cephalic angle used for a lateral knee?

to superimpose the condyles

What causes distal condylar rotation?

lower leg parallel to IR or not using cephalic angle

What causes anterior/posterior knee rotation?

condyles not superimposed

What kind of rotation is this?

distal condylar rotation

What kind of rotation is this?

anterior/posterior rotation

What does a trauma lateral knee demonstrate?

air fluid levels and effusion into the joint space

The external oblique of the knee demonstrates:

• patella slightly off lateral aspect of femur

• fibula superimposed over lateral aspect of tibia

• demonstrates medial side

The internal oblique of the knee demonstrates:

• patella slightly off medial aspect of femur

• proximal tibiofibular joint is demonstrated

• demonstrates lateral side

What does the Settegast method demonstrate?

the patellofemoral joint

What are the 4 ligaments of the knee and their functions?

medial collateral ligament (MCL): prevents lateral sliding

lateral collateral ligament (LCL): prevents lateral sliding

posterior cruciate ligament (PCL): prevents anterior sliding

anterior cruciate ligament (ACL): prevents posterior sliding

What type of joint is the femorotibial joint?

diarthrodial, synovial, hinge

What type of joint is the patellofemoral joint?

diarthrodial, synovial, gliding

What are the 2 major bursae of the knee joint?

suprapatellar (anterior femur)

infrapatellar (anterior tibia)

What are the anterior tendons/ligaments that connect the patella to the leg?

patellar ligament extends from apex of patella to tibial tuberosity

quadriceps tendon attaches to the base of the patella and the quadriceps femoris muscle

Explain Osgood Schlatter’s disease

patellar ligament becomes inflamed and pulls away from the tibial tuberosity due to overuse

occurs most commonly in in athletic, adolescent boys

Explain the Baker’s cyst

popliteal cyst found in conditions where there is a chronic swelling of the semimembranous bursa (arthritis, meniscus injuries, ligamentous injuries)

Explain varus

lower leg points medially (bow legged) due to narrowing of the medial joint space

Explain valgus

lower leg points laterally (knock kneed) due to narrowing of the lateral joint space

What is the flabella?

sesamoid bone located in the knee area (varies in size and shape, and occurs in 25% of people)