the knee and related structures f09
TRANSCRIPT
The Knee and Related Structures
The KneeBones
FemurPatella
Largest Sesamoid bone in human bodyTibiaFibula
Non-weight bearing bone
ArticulationsFour Articulations
Femur and Tibia Femur and Patella Femur and Fibula Tibia and Fibula
MeniscusTwo oval fibrocartilages that sit in the tibia
Semi-lunar (half moon shape)Stabilize the knee
Especially the medial, when the knee is flexed at 90 degreesMedial
C-shaped Attach to the tibia, joint capsule by the coronary ligament, and the
semimenbranous muscle (hamstring)Lateral
O-shaped Attached to the tibia, loosely to capsule, and popliteal tendon, and
ligament of WristbergBlood Supply
Divided into 3 circumferential zones Red –Red Red-White White-White
Avascular
3 Zones of Meniscus
Stabilizing LigamentsAccount for a considerable amount of knee
stabilityTwo ligamentous bands that cross one another
within the joint capsule of the knee Anterior Cruciate Ligament (ACL)
3 twisted bands Prevents the femur from moving posteriorly weight
bearing and anteriorly non-weight bearing. Stabilizes the tibia from excessive internal rotation
(IR) Posterior Cruciate Ligament (PCL)
Resists IR of the tibia Prevents hyperextension of the knee
ACL & PCL
Common Cause of ACL Tear
Common Cause of PCL Tear
Situations in which the PCL can tear include -excessive hyperflexion (forced bending), eg falling onto the shin with a bent knee and foot pointed dashboard injury in a car - where the knee is bent to a right angle and a sudden force drives the tibia backwards
Medial Collateral LigamentSuperficial ligament(MCL) is separate from the
deeper capsular ligament.Attaches above the join line on the medial epicondyle
of the femur and below on the tibia – Just beneath the attachment of the pes anserinus (hamstring tendons)
Deep medial capsular ligaments Primary purpose are to attach the medial meniscus to the
femur and to allow the tibia to move on the meniscus inferiorly
Lateral Collateral LigamentSize of a pencilAttached to lateral epicondyle of the femur and to the
head of the fibula.Taut during knee extension but relaxed during flexion
More Structures of the KneeJoint Capsule
Knee joint is surrounded by the LARGEST joint capsule in the body.
Contains: infrapatellar pouch, fat,pad, and bursae, MCL, and other ligaments.
Divided into Four regions – are reinforced by other anatomical structures Posterolateral & medial Anterolater al & medial
Knee Musculature13+ Muscles Movements of the Knee
Knee Flexion & Extension External & Internal Rotation
BursaeReduce friction2 dozen have been identified in the knee
Fat PadsSeveral pads located around the kneeInfrapatellar fat pad is the largest
Nerve & Blood Supply
Specific InjuriesMedial & Lateral Collateral Sprain
Hit from opposite side of legACL & PCL Sprain
ACL= lower leg is rotated while the foot is fixed (jumping) PCL=fall with full weight on the anterior aspect of the bent knee
with the foot in plantar flexion (sliding)Meniscal Lesions
Most common= weight bearing combined with a rotary force while running
Patellar Conditions Patellar orientation predisposes you to have certain types of
injuries Acute patellar subluxation or dislocation Chondromalacia
Softening and deterioration of the articular cartilage on the back of the patella
Three stages Patellofemoral Stress Syndrome
Some lateral deviation of the patella as it tracks in the femoral groove
MCL & LCL Sprain
Meniscal Lesions
Patellar Tracking
Patellar ExaminationThe Q-Angle
Quadriceps angle Normal is 10’ Males / 15’ Females20’ (+) predisposed to
patellar subluxation/dislocation
Extensor InjuriesOsgood-Schlatter Disease
Pain at the attachment of the patellar tendon to the tibial tubercle
Can lead to avulsion fractureLarsen-Johansson Disease
Occurs at the inferior pole of the patella Excessive repeated strain on the patellar tendon
Patellar Tendinitis (Jumper’s/Kicker’s Knee) Repetitive trauma Extreme tension on the knee extensor muscle complex Painful at patellar or quadriceps tendon
Iliotibial Band Friction Syndrome (runner’s knee)General expression for many repetitive and overuse
conditions Malalignment and structural assymetries of the foot
and lower leg.
Extensor Injuries
Patellar tendonitis can be classified by the following techniques: Stage 0 - No Pain Stage 1 - Pain only after intense sports activity; no undue functional impairment Stage 2 - Pain at the beginning and after sports activity; still able to perform at a satisfactory level Stage 3 - Pain during sports activity; increasing difficulty in performing at a satisfactory level Stage 4 - Pain during sports activity; unable to participate in sport at a satisfactory level Stage 5 - Pain during daily activity; unable to participate in sport at any level
Knee Joint Rehabilitation
General Body ConditioningWeight BearingKnee-Joint MobilizationFlexibilityMuscular StrengthNeuromuscular ControlBracing / TapingFunctional ProgressionReturn to Activity