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Knee Ch.18
Knee
Question | Answer |
---|---|
What is the jt. structure of the knee? | No bony stability @ knee only soft tissue |
What is the most frequently injured joint? | Knee |
What is the largest joint in the body? | Knee |
What type of joint is the knee? | synovial, hinge joint; uniaxial (flexion/extension) |
What is the accessory motion of the knee joint? | Rotation |
Are the femoral condyles concave or convex? | Convex |
Is the Tibial plateau concave or convex? | Concave |
What actions must take place so the femur does NOT roll off the tibial plateau? | Roll & glide |
Is the femoral condyle larger then the tibial plateau? | Yes |
Which condyle is larger, medial or lateral? | Medial condyle |
What caused the accessory motion of rotation? | The medial condyle is larger and causes a spin. |
At the end of an OKC motion of the knee, what position is the tibia in? | External rotation |
At the end of an CKC motion of the knee, what position is the tibia in? | Internal rotation |
What do we call a "locked" knee? | Screw home mechanism |
What must be done to "unlock" the knee? | Internal rotation of the tibia @ the knee |
What muscle "unlocks" the knee? | Popliteus muscle of the knee |
Where is the patellofemoral joint? | It is the articulation between the femur & patella |
What is the job of the patella? | Increases mechanical advantage of quads and protects the knee joint |
Explain the term "Q angle" (patellofemoral angle) | The angle between the quadriceps & the patellar tendon. The ASIS to the mid pt. of the patella and the mid pt of the patella to the tibial tuberosity. Increases for femails. |
What is the normal range for the "Q angle"? | 10-18 degrees (greater for females due to wider pelvis) |
What is the ratio for the hamstrings strength? | 3:2 |
What is the ratio for the hanstrings strength without the patella? | 1:1 |
What is ACL? | Anterior cruciates ligament |
What is PCL? | Posterior cruciates ligament |
Where does the ACL attach? | (Cross your fingers and place on your knee - top finger represents the ACL) Anterior tibia medially & medial meniscus X superior/posterior (lateral) to lateral condyle of the femur. |
Where does the PCL attach? | (Cross your fingers and place on your knee - bottom finger represents the PCL)Posterior tibia X superior/anterior to medial condyle of the femur |
What working together provides stability for the knee in the sagital plane? | ACL & PCL (they support the roll and glide) |
What prevents the tibia from gliding anteriorly on the femur? | ACL |
What prevents the tibia from gliding posteriorly on the femur? | PCL |
What ligament is tight in extension and prevents hyperextension? | ACL |
What ligament is tight in flexion? | PCL |
Which knee ligament is thicker, stronger, and injured less and not always fixed? | PCL |
What is MCL? | Medial collateral ligament |
What is LCL? | Lateral collateral ligament |
What working together provides stability for the knee in the frontal plane? | MCL & LCL |
What collateral ligament is flat & broad and frequently torn? | MCL |
What collateral ligament attaches to the medial condyles of the femur and tibia? | MCL |
WHat collateral ligament attaches to the medial meniscus? | MCL |
What collateral ligament is round, cord-like & feels like a pensil? | LCL |
What collateral ligament attaches to the lateral condyle of the femur and head of the fibula? | LCL |
What collateral ligament is not often injured? | LCL |
What does the meniscus of the knee look like? | 2 half-mooned, wedged, fibrocartilage. Thicker more lateral then medial |
What does the meniscus of the knee do? | Deepens the articular surface and becomes a shock absorber |
Which menisci is oftern torn, the medial or lateral? | Medial |
Frontal plane of knee = ? | Injury |
WHat creates the terrible triad? | ACL, MCL and medial meniscus |
True or false: all 3 parts of the terrible triad are usually damaged at the same time when an injury occurs? | True |
How many bursa are in the knee? | 13 |
What do bursa do? | Decrease friction, communicate w/jt. of the knee |
Where do you find the prepatellar bursa? | Anterior surface, between the patella and the skin |
What are the muscles in the anserine or pes anserine group? | Sartorius, gracilis, & semitemdinosus |
The anserine bursa is located? | Medially wider the sartorius, gracilis, and semitendinosus |
Where is the popliteal fossa bursa? | Between the popliteus tendon & the lateral femoral condyle |
Can the popliteal space be easily damaged? | Yes |
Genu Valgum | "Knock knees" |
What do your legs look like if you have genu valgum? | Valgus increase laterally / displacement of distal end of the tibia |
Genu Varum | "Bowlegs" |
What do your legs look like if you have genu varum? | Varum increasesmedially / displacement of distal end of the tibia |
Combination deformities switch @ the knee so if you have Coxa Valga... | You have genu varum & supination |
Combination deformities switch @ the knee so if you have Coxa Varum... | You have genu valgum & pronation |
Genu Recurvation | "Back knees" greater then 0 degrees of hyperextension. Knees go backwards. |
Paterrar Tendinitis | Tendon overuse; "jumper's knee" overuse or sudden impact (contract w/o stretch) |
Osgood-Schlatter's | Overuse tendon pulls @ traction epiphysis @ tibial tuberosity. Causes bone growth (Wolf's Law) & possible avulsion. Tibial tuberosity can come off. |
Baker's Cyst | Bursitis in posterior knee (popliteal region) |
Patellofemoral Pain Syndrome | Anterior knee pain, poor tracking, increased Q angle, weak quads espically medially, tight lateral quads, and pronated feet |
Chondromalacid Patellae | Dying cartilage; degeneration (softening) of the cartilage of the posterior patella (very painful) |
What is another name for Prepatalar bursitis? | Housemaid's knee |
What is Prepatalar bursitis? | Pressure of the patella's bursa |