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The Knee Lecture 11.

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Presentation on theme: "The Knee Lecture 11."— Presentation transcript:

1 The Knee Lecture 11


3 The Knee Complex the knee is a large complex joint frequently injured during sport participation the knee is positioned between the two longest bones in the body - the femur and the tibia creating potential for high torque’s this factor coupled with poor bony stability makes the knee very susceptible to injury

4 Tibiofemoral Joint articulation of the distal femur and proximal tibia form a modified hinge joint movement in 2 planes - Flex /Ext , lnt /Ext rotation because of the size and shape of the condyles the tibia can rotate on the femur

5 this lateral rotation of the tibia on the femur (only a few degrees) provides a locking of the knee or a "screwing-home mechanism" stability and support provided by menisci and supportive ligaments


7 Menisci are fibrocartilage discs that are attached to the tibia by coronary ligaments and joint capsule they are thicker along the lateral margin and thinner medially - the medial meniscus is injured more frequently than the lateral meniscus blood supply only in outer 1/3 of meniscus


9 Medial Meniscus 'C' shaped, strongly attached to the tibial surface therefore less mobile one reason injured more often also attached to the joint capsule (medially)

10 Lateral Meniscus more complete ( almost circle shaped) loosely attached to tibial surface - less commonly injured

11 Functions of the Menisci
stability - deepens socket and wedge shaped to prevent A-P motion -increase surface area of femoral condyles shock absorption provide nutrition because it promotes synovial fluid flow and distribution - proprioception function through its innervation

12 Meniscal Tears associated with ligaments disruptions, degenerative changes, repetitive stress secondary to chronic ligamentous laxity, isolated or repetitive rotational stresses

13 Ligaments of the Knee the stabilizing role of the ligaments that cross the knee is very significant two major ligaments are the anterior and posterior cruciates ( called cruciate because they cross each other inside the knee joint) two other ligaments are the medial and lateral collateral ligaments

14 Anterior Cruciate Ligament
separated into to bundles according to their functions, ( not really separate) spiral around one another, insert as one board ligament spiral arrangement plus the broad attachment allow ACL to provide stability through out the full ROM

15 ACL most common and serious injury to the knee
susceptible to injury with a valgus force, external rotation strong quad contraction of knee hyperextension ACL is subject to deceleration injuries , internal tibial torque is the most dangerous loading mechanism, particularly when combined with an anterior tibial force


17 Posterior Cruciate Ligament
not as commonly injured as ACL stronger and shorter than the ACL prevents posterior tibial translation and knee hyperextension common mechanism collision or fall on tibial tuberosity

18 Medial Collateral Ligament
provide valgus, external rot support (note ACL is also very imp in this function) basically a thickening of the medial capsule superficial layer and a deep layer

19 Lateral Collateral Ligament
cord like structure considered to be extra capsular less commonly injured b/c of varus mechanism and less debilitating

20 Dynamic Knee Support ITB, hamstrings, quads , gracilis , gastroc
the key to injury rehab and prevention


22 Bursae Suprapatellar, prepatellar, superficial infrapatellar and deep infrapatellar i) suprapatellar largest in the body lies between the femur and the quads tendon of the rectus femoris ii) prepatellar - located between skin and anterior surface of patella allowing for movement of then skin over the patella

23 iii) superficial infrapatellar - located between the skin and the patellar tendon
-inflammation this are due to excessive kneeling referred to as housemaid's knee iv) deep infrapatellar - located between the tibial tuberosity and the patellar tendon reduces friction between tendon and bony tuberosity



26 Patellofemoral Joint patella articulates with the femur

27 Patella largest sesamiod bone in the body
located within the quads tendon articulates with the femoral condyles patella facets -under surface of patella

28 Common Injuries to the Knee

29 1) Contusions and Bursitis
result from a compressive force - a fall , a kick generally they are locally tender, with pain, swelling and ecchymosis Bursitis - may be caused by a direct trauma or possibly infection swelling usually occurs over a 24 hour period Rx - PIER - protection - may need draining but this may add complications

30 2) Ligament Injuries one plane instabilities
i) MCL pain and swelling usually found along the medial joint line ii) LCL pain and swelling are found on the lateral aspect of the knee

31 MCL injuries straight lateral forces or valgus causes tension on the MCL

32 Signs and symptoms medial knee pain Swelling Medial joint laxity RX - PIER, hinge knee brace for stability , crutches , most MCL injuries are treated non surgically



35 LCL injuries medial forces or varus force produces tension on the LCL
Much rarer injury than MCL

36 Signs and symptoms Lateral knee pain Localized swelling Lateral joint laxity RX: PIER, hinge knee brace for stability , crutches , most LCL injuries are treated non surgically

37 ACL injuries ACL prevents forward translation of the tibia on the femur, also assists with controlling valgus and varus forces , and helps prevent hyperextension MOI : damage to the ACL usually results from a cutting or turning maneuver, landing off balance or a sudden deceleration

38 s/s Pain , instability , swelling , may often hear or fell a pop in the knee, decreased ROM and function pain described as being felt deep in the knee or on either side of the patellar tendon joint effusion is usually bloody and fairly rapid onset


40 PCL injury PCl prevents the tibia from moving posterior on the femur
MOI: a direct blow to the anterior tibia ( dashboard injury) , or hyperflexion or hyperextension s/s Large tense knee effusion Discomfort attempting to flex the knee beyond 90 degrees RX: PIER, crutches , referral to surgeon , however this is not often repairs..

41 Multidirectional Instabilities – injuries to multiple structures


43 First Aid Care ( knee ligaments )
Apply ice and compression immediately , brace to protect , crutches If knee unstable , have athlete seek proper medical advice Most ACL tears are referred to a orthopedic surgeon, due to the continued instability of the knee Repairs….

44 3) Meniscal Injuries compression, tensile and shearing force often cause damage to the mensci tears may be - longitudinal , bucket handle , horizontal or parrot-beak medial mensicus is more often damaged more common in men between the age of and women between joint line pain and general joint effusion, pain with rotations and extreme flexion

45 individual may experience clicking , popping or grinding
the knee may give way or buckle the individual may have difficulty doing squats and or duck walking the meniscal tear may lodge in the joint causing locking surgery is usually necessary to unlock this condition mensici become stiffer and less resilient with age RX – PIER – rest and time possibly surgery



48 First Aid Care Apply ice and compression immediately ,, crutches
If knee blocked or locked , have athlete seek proper medical advice ASAP Repairs….

49 4) Patellofemoral Stress Syndrome
usually caused by weakness in the VMO or lateral retinaculum is too tight this condition is more commonly found in women due to a higher Q angle Q angle is the angle between the line of the quads ( RF) and the patellar tendon a Q-angle of less than 13 and more than 18 may predispose the athlete to PFS

50 pain may be dull and aching generally in the centre of the knee or on lateral edge of patella
point tenderness usually over lateral edge of patella, often associated with anterior knee pain crepitus or grinding often present - especially upon compression of the patella Rx - PIER - NSIADS -taping- VMO strengthening , education


52 5) Subluxation or Dislocation of Patella
commonly occurs during deceleration or cutting maneuver patella moves laterally and may tear medial retinaculum leading to an audible pop and a collapse of the knee

53 the patella may remain displaced or reduce itself
may need to be reduced by doctor pain and swelling , Rx- PIER, immobilization, exercise and education

54 First Aid Care Apply ice and compression immediately , splint leg, crutches Arrange transportation to nearest medical facility

55 6) Patella Tendinitis aka jumpers knee
patellar tendon becomes inflamed and tender from repeated jumping (eccentric knee extension activities)

56 pain located on inferior pole of patella
pain increases on stairs, after prolonged sitting and during resisted knee extension as condition worsens time and duration of pain may change or worsen Rx- PIER, NSAIDS, modalities, exercise and stretching..

57 7) Osgood-Schlatter Disease
traction type injury to the tibial tuberosity where the patellar tendon inserts more common in boys aged 10-15 pain and swelling are present with activity usually diminish with rest in cases with long duration the tibial tuberosity may become enlarged

58 condition usually rectifies itself (within 12 to 24 months) with age and closure of the growth plate
Rx – symptomatic and self limiting


60 8) Unhappy triad Medial meniscus Anterior cruciate ligament and Medial collateral ligament

61 Possible Factors Influencing Increased rate of ACL injuries in Women
Intrinsic Factors Ligament size Ligament laxity Intercondylar notch dimensions Limb alignment ( wider pelvis, genu valgum , external tibial torsion) Estrogen levels

62 Stylistic differences in sport play
Extrinisic Factors Level of skill Level of experience Shoe friction Ankle braces Stylistic differences in sport play Plant and cut, straight leg landing, one step stop landing , pivoting with sudden deceleration Muscle strength imbalances (eccentric hamstrings strength relative to eccentric quad strength )

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