Sports Med: The Knee

bones of the knee

femur, tibia, fibula, patella

parts of the femur

medial femoral condyle: attaches MCL

lateral femoral condyle: attaches LCL

intercondylar notch

femoral trochlea

parts of the tibia

tibial plateau: meniscus sits on it

tibial tubercle (tuberosity): patellar tendon connects

fibula

serves only as a place of attachment for LCL and biceps femoris

patella

sesmoid (free floating), serves as attachment for quadriceps to patellar tendon

parts of the patella

apex: pointed, inferior portion

base: flat side, superior

lateral facet

medial facet

ACL (anterior cruciate ligament)

can't repair itself, can only be reconstucted

prevents anterior translation of tibia

usually torn with valgus, rotation, and possibly hyperextension

more prevalent in females

hamstrings protect ACL, therefore when torn they will keep the knee in flexion and play a part when playing without ACL

PCL (posterior cruciate ligament)

prevents posterior translation of tibia

most common mechanism of injury is direct blow to anterior, proximal tibia

MCL (medial collateral ligament)

usually 3rd degree and heals with immobilization

connects tibia and femur

originates from adductor tubercle on femur

prevents and is injured by valgus force

naturally more tight than LCL

LCL (medial collateral ligament)

connects fibula and femur

prevents and is injured by varus force

naturally looser than MCL

muscles of the knee

quadriceps (rectus femoris, vastus medialis [VMO], vastus intermedius, vastus lateralis) hamstrings (biceps femoris, semi membranosus, semi tendonosus), gastrocnemius

quadriceps

has strength advantage due to number of muscles

rectus femoris

2 joint muscles crossing hip and knee

causes hip flexion and knee extension

vastus medialis (VMO)

only dynamic stabilizer of the patella (can cause subluxation and dislocation)

vastus intermedius

hard to palpate, under rectus femoris

vastus lateralis

can cause lateral dislocation if too tight

hamstrings

all originate from iscial tuberosity and have a mechanical advantage due to multiple insertions on tibia

biceps femoris

lateral, attaches to fibula

semi-membranosus

medial, attaches to tibia

semi-tendonosis

medial, attaches to tibia (long tibia at attachment)

gastrocnemius

with hamstrings form popliteal fossa behind the knee

popliteal fossa

the area behind the knee where nerves and LE blood supply travels

plica

located within synovium of the joint

starts along medial joint line and extends up and under the patella

frequently become inflamed and cause pain on trap test

can be mistaken for the meniscus tear

starts lateral and foes to medial side of patella under quad tendon

meniscus

functions as shock absorber and stabilizer

medial is larger and less mobile than lateral and is torn more often, attached to MCL and tibial plateau by coronary ligament

lateral is smaller and more mobile (can play with this torn while weight bearing medial would cause problems)

mechanism of injury is twisting, symptoms include pain

is sometimes repaired by cutting out injury

knee motions

flexion, extension, internal rotation, external rotation, anterior translation of tibia, posterior translation of tibia, valgus (in), varus (out)

SOAP

subjective: what the patient tells you

objective: what you test for or find

assessment: athletic trainer's diagnosis

plan: what will happen next

McMurray's

meniscus

valgus stress

MCL

varus stress

LCL

Lachman, anterior drawer

ACL

Posterior drawer, 90 degree sag

PCL

trap test

plica, condromalacia

apprehension

patellar instablility

patellar instability

dislocation and subluxation almost always go sideways

the greater the q angle, the larger the pull on the patella

vastus medialis is dynamic stabilizer

vastus lateralis is possible cause of lateral dislocation

lateral femoral condyle and trochlea/apex relationship is the static stabilizer

patellar instability rehab

REHAB: first restore full ROM through bike, heel slides, patellar mobilization, build up VMO strength through quad sets, SLR and mini squats, work on hamstring and quad flexiblity

q angle

the relationship between the angle of the femur in relation of the tibia. 12-15 degrees is normal

MCL rehab

healing time is 2-6 weeks

rehab goals include controlling swelling, ROM, and quad strength

when strength is up, go into functional sports drills

ACL rehab

4-6 months

initial goals include controlled swelling, FWB, quad strength, ROM

secondary include running at 10-12 weeks post op, functional strengthening

functional include beginning sport specific goals when strength is achieved

meniscus rehab

menisectomy has NWB for 1-2 weeks, back to sport in 4-8 weeks

meniscus repair is NWB 2-4, sport in 2-4 months

chondromalacia

roughening of cartilage under patella

treatment is RICE, cross training

rehab is VMO strengthening, hip strengthening, hamstring stretches

hyperextension

injury to the bone (contusion) and capsule

treatment is RICE

rehab is flexibility, strengthen hamstrings, quad, hip musculature

patellar tendonitis

runner/jumper's knee

treatment is RICE

rehab is cross training, hamstring stretching, VMO strength

signs of ACL tear

swelling, pop, instability

signs of PCL tear

pain on back of the knee

signs of MCL tear

pain and swelling on the medial part of the knee

signs of LCL tear

pain on outside of the knee