Knee MSK Flashcards
Largest joint in the body
knee
Hyaline articular cartilage what type
Type II collagen
Collagen types
Type I: Skin and normal tendons
Type II: Hyaline/articular cartilage
Type III: Tendinosis tendons
Type IV: Basement membrane
Segond fx
when you tear your ACL and you get a lateral tibial plateau fracture
ACL attachment/insertion
starts on femur and runs antero-infero medially to attach onto the tibia
ACL tenses with and muscle imbalance for injury
knee extension;; Weak hamstrings and stronger quadriceps causes imbalance forces on the ACL and may increase the risk of a tear in women.
With knee flexion wthe tibia will curve under the femur which will cause the ACL to pull the femur ___
anteriorly
PCL origin/insertion
starts on femur and runs postero infero laterally to attach onto the tibia
PCL tenses with
knee flexion;
Because of increased force in the patellofemoral compartment, patients with a PCL-deficient knee are more prone to patellofemoral arthritis.
PCL limits
posterior translation of tibia
Conjoint tendon
houses semitendinosus and biceps femoris medially, semimembranosus tendon originates laterally; ultimately going down the thigh the muscles separate out as MTB going medially to laterally
Semimembranosus and semitendinosus innervation
L4,L5, S1 sciatic nerve (tibial division)
Biceps femoris innervation
L5,S1 sciatic nerve tibial division long head fibular division short head
Sartorius
starts at ASIS and attaches at knee, hip flexor and knee flexor
Hip flexor and knee flexor
sartorius
Gastroc
S1,2 tibial nerve, flexes te knee as well as plantar flexes ankle
Quad- rectus fem, vast intermed, vast medialis, v LAT
L2,3,4 femoral nerve
Knee internal rotators
semimembranosus, semitendinosus, Sartorius, gracilis , Say grace before tea + semimembranosus
knee external rotators
biceps femoris
unlocks knee
popliteus muscle
risk factors for knee OA
trauma, obesity, weak quad muscles and weak hip muscles
popliteal artery entrapment syndrome
young males usually, gastrocs , pop pulse diminishes with plantar flexion, lower limb swelling and discomfort with mild disease otherwise vascular bypassnumb/ting in lower limb or foot, arteriogram, activity modificatoin
most comonly injured ligmaent in sports
ACL
most commonly injured ligament overall
MCL
brace for ACL tear
Lenox Hill derotation orthosis
Bakers cyst location
between medial head of gastroc and semimembranosus
Tx for patellofemoral pain syndrome
RICE, IT band vastus lateralis stretching and VMO and hip girdle strengthening (quad imbalance, more lateral pull, so want to make it more medial), patellar sleeve, kinesiotape for tracking, surgery if fails after 6 months
Chondromalacia Patella
Generally sequela of patellofemoral pain syndrome, patellar cartilage degenerates and becomes soft due to improper tracking, MRI, arthroscopy, XR
Jumpers knee location
Inferior pole of patella, proximal patellar tendon
tx of patellar tendonitis
quad strengthening and stretching, PRP or tendon scraping (tendonosis)
Popliteus tendonitis
pain in lateral knee, often due to downhill skiing or running
Snapping knee from what
IT band snapping over lateral femoral condyle
Cause of IT band syndrome
Weakness/tightness of TFL/IT band and hip abductors (glut med)…most pain in 30 deg knee flexion, nobles test postive with 90 deg knee flexion
Ober test
side lying raise affected leg, abduct leg and let it drop, if it floats for a little bit then IT band tight, tests for IT band syndrome.
Patello femoral syndrome caveat
A shallower-than-normal patellofemoral contour would imply that the patella does not “stay in its lane”, and may easily veer off towards the shallow side, since it does not have good bony anatomy keeping it in place. This veering off is the reason for these patients’ knee pain… so if shallow medial patellofemoral contour then you would want to do vastus lateralis Strengthening and vastus medialis stretching!
right leg single leg squat while twisting on the right knee.
Thessaly test, meniscal tears
deep squatting while pivoting under resistance is a classic mechanism for
lateral meniscus tears.
significance of q angle
The Q-angle is measured with one line from the ASIS to the central patella. Another line is drawn from the tibial tuberosity through the central patella. The Q angle is typically measured for evaluation of patellofemoral pain syndrome.
A larger Q-angle may create a larger lateral vector and potentially a greater predisposition to lateral patellar tracking when compared to a smaller Q-angle;;;; also increased risk for patellar sublux
Q angle associated with genu **
increased Q-angle is
traditionally associated with a valgus knee
Q angle females and males
Normally, Q angle is 14° for males and 17° for females.
What things increase q angle
increased by genu valgum increased femoral anteversion external tibial torsion a laterally positioned tibial tuberosity or a tight lateral retinaculum.
also from Hip adduction and internal rotation
Basically, any biomechanical factor that causes the tibial tuberosity to be laterally displaced in relation to the central patella or ASIS will increase the Q-angle.
arcuate popliteal ligament complex function
to provide posterior and lateral rotary stability .. posterior horn of the lateral meniscus attaches here
Superficial posterior compartment of leg
gastrocnemius
plantaris
soleus
Deep posterior compartment
tibialis posterior
flexor hallucis longus
flexor digitorum longus
popliteus
medial and lateral patella facets in contact with the sulcus?
45 deg
WB after ACL reconstruction
Immediate weight-bearing should be advised to reduce patellofemoral pain…. want to avoid , open chain exercises and isokinetic quadriceps strengthening
Posterolateral corner injury
pain in posterior knee
posterolateral corner is a complex of ligaments that brings stability to the posterolateral aspect of the knee. The arcuate ligament, fibular collateral ligament, and popliteus muscle tendon make up this complex.
The common peroneal nerve lies between the first and second layers (between the IT band/biceps and LCL) of the outer knee.
Test with DIAL test
The most likely scenario is popliteal tendonitis considering downhill running and method of palpation. Remember, the posterolateral corner complex is made up of the arcuate ligament, fibular collateral ligament, and popliteus muscle tendon.
Fulcrum test
most indicative of a femoral stress fracture (distal)
