Lab - Knee Anatomy & Assessment Flashcards
Knee joint type and positioning?
Modified hinge joint b/c of tip rotation
Closed pack position = full ext, slight lat rotation of Tib.
Loose pack position = resting - 25° of flex
Menisci and FUnction
Med (and coronary) –>
Lat (and coronary) –>
- Shock absorb
- Create smooth glide (can’t make anything w/ less friction),
- Increase congruency of joint (fits tib and femur together better).
- Deepens articular surface of joint
Knee Ligs.
ACL = primary rotary stabilizer, prevents posterior displacement of femur on tib, weaker than PCL
PCL = primary rotary stabilizer, prevents anterior displacement of femur on tib, much less common to be injured
Both named for where they attach on tib.
MCL = side to side stability, superficial and deep layers - deep layer blends into medial meniscus. More common.
LCL = side to side stability, runs from lat femoral condyle to head of fib., separate from meniscus.
Med/ lat coronary Ligs. = attach the meniscus to the tib plateau. Can be injured during menisci injury.
Joint capsule surrounds knee
Fibrous band of fascia = Iliotibial Band (IT) –> from the TFL and glute max. Attahces to lateral tib tubercle (GERDY’s Tubercle).
Bones of knee?
Femur (lat/ med condyles)
Tib (tib plateau, tib spine - divides knee into med/ lateral sides and where ACL/ PCL attach to, tib tubercle - patellar tendon insertion)
Fib (head is proximal, lat malleolus is distal, doesn’t touch femur - connected by LCL)
Patella (sesamoid bone, back of patella is wedged shaped and lined w/ the thickest articular cartilage in the body)
Mscs of Knee
- Quadriceps Femoris (RF, VM(O), VL, VI) Vastus medialus OBLIQUIES (curved portion of VM at the bottom of msc - important for end range knee extension, atrophy occurs quick, important for Patellar alignment
- Patellar Tendon (quad to tib tubercle)/ lig. (patella to tib tubercle)
- Hamstrings (3) - BF (lateral big tendon), ST, SM (both together on medial - more tendon feel = ST –> from ischial tuberosity
- Popliteus - unlocks knee from full extension - IR
- Gastroc
- Plantaris
- Adductors (adductor Magnus)
- Sartorius (longest msc in body - ASIS to med tib.)
- Gracilis - inserts at med tib.
Pes Anserine = goose foot
- Anteromedial portion of the proximal tib.
-attachment point for 3 mscs (Sartorious, Gracilis, ST)
- Also a bursa
- Say GRACE before Tea
- Often forgotten
Bursae and locations
Fluid filled sac to decrease friction b/w two surfaces
- Prepetallar (in front/ on top of patella)
- Suprapatellar (above)
- Infrapatellar (deep and superficial) - below and above petellar tendon
- Popliteal (bakers cyst) –> in popliteal fossa - herniation of that bursa
Pes Anserine –> localized swelling
Arteries of knee
Femoral a. –> popliteal a. at knee –> ant and post a.
Knee arteries = Genicular arteries (4) –> wrap around and above/ below knee
Nerves of Knee
Sciatic n.leads to femoral n. (quads) and hamstrings - branches into tib and common peroneal n.
Mvms of Knee
Flex = 130 -140°
Extn = 0° or a bit more
Med/ Lat rotation (at 90° flex)
Knee assessment (Observation)
Swelling?
- localized = bursa
- Generalized = intra-articular
Atrophy?
- VMO and calves are common
Alignment Deformities?
- Genu Valgum (knock-knee) - more load on lateral structure
- Genu Varum (bow legged) - more load on medial
- Genu recurvatum (back knee’d)
Knee injury Symptoms –> Delayed Swelling
- meniscal injury
- Capsular injury
- Synovial injury
Knee injury Symptoms –> Immediate Swelling
- ACL/ PCL
- Acute tendon injury
- #
- MCL/ LCL
Knee injury Symptoms –> Giving Way
- Lig. sprains
- Subluxed patella
- Loose body
- Meniscal injury
Knee injury Symptoms –> Crepitus?
- #
- Arthritis
Knee injury Symptoms –> Locking/ stuck?
- loose body
- meniscal injury
Hemarthrosis?
bleeding in the joint (ACL rupture)
Effusion?
fluid in the joint (intracapsular - synovial injury)
Eccymosis
- blood/ bleeding in the tissue (Bruise)
Edema
Swelling in Connective tissue (pitting edema)
