The Knee Complex

1. Physiotherapy PY 401 Biomechanics & Kinesiology The Knee Complex

2. Objectives Able to: Know and describe the type of joint Know and describe the articulations of the knee joint Know the muscle origin, insertion, nerve supply and describe actions they perform at the knee joint. The structures of the knee joint including ligaments, meniscus and bursae . Know and describe the nerve, arterial and venous supply at the knee. Know and describe the different movements of the knee. Know and describe application of biomechanics and kinematics of the knee joint in Physiotherapy diagnosis, treatment and rehabilitation.

3. Introduction Function To allow locomotion with minimum energy requirements from the muscles and stability, accommodating for different terrains. To transmit, absorb and redistribute forces caused during the activities of daily life

4. Type of Joint The knee is classified as a; Synovial / diarthroses - a freely moveable joint. Uniaxial joint- does only 1 degree of movement. Hinge joint- moves in one plane with slight rotational movement, but the rotation is not enough to be considered significant.-

5. Articulations The knee (art. Genu ) Type of joint: hinge joint Articular surface: Tibiofemoral joint Patellafemoral joint

6. Tibiofemoral joint Articulation surfaces; Femur The articular surface of medial and lateral condyles articulates with the distal end of tibia. Anteriorly patellar groove allows engagement of the patella during early flexion.

7. Tibiofemoral joint Tibia articulation Tibial plateaus are predominantly flat Slight convex at the anterior and posterior margins Because of this lack of bony stability, menisci are necessary to improve joint congruency.

8. Patellarfemoral joint Articulation between patellar and femur. Articular surface Patella Medial and lateral facet which are flat to slightly convex side to side and top to bottom.

9. Articulation of knee joint

10. Ligaments The stability of the knee is due mainly to the ligaments. A ligament is several large fibrous bands of tissue, comparable to that of a rope, they support the knee on both sides and front to back. Ligaments connect bone to bone.

11. Ligaments The ligaments may be divided into those that lie outside the capsule and those that lie within the capsule. Extra Capsular Ligament Ligamentum Patella Lateral Collateral Ligament Medial Collateral Ligament Oblique Popliteal Ligament Intra Capsular Ligament Anterior Cruciate Ligament Posterior Cruciate Ligament Ligaments of the menisci; Coronary ( Meniscotibial ) Ligament Transverse Ligament

12. Extra Capsular Ligament. Ligamentum Patella Attached above to the lower border of the patella and below to the tuberosity of the tibia. Continuation of the central portion of the common tendon of the quadriceps femoris mm. Lateral Collateral Ligament Cord like and is attached above to the lateral condyle of the femur and below to the head of the fibula. The tendon of the popliteus mm intervenes between the ligament and the lateral meniscus. Medial Collateral Ligament A flat band and is attached above to the medial condyle of the femur and below to the medial surface of the shaft of the tibia . It is firmly attached to the edge of the medial meniscus. Oblique Popliteal Ligament A tendinous expansion derived from the semimembranosus mm. It strengthens the posterior aspect of the capsule.

13. Intracapsular Ligament. Cruciate Ligaments Two strong Intracapsular ligaments that cross each other within the joint cavity. They are named anterior and posterior according to their tibial attachment. i . Anterior Cruciate Ligament Attached to the anterior intercondylar area of the tibia and passes upward, backward and laterally to be attached to the posterior part of the medial surface of the lateral femoral condyle . Prevents posterior displacement of the femur on the tibia. With the knee joint flexed, the ACL prevents the tibia from being pulled anteriorly. Posterior Cruciate Ligament Attached to the posterior intercondylar area of the tibia and passes upward, forward and medially to be attached to the anterior part of the lateral surface of the medial femoral condyle . Prevents anterior displacement of the femur on the tibia. With tibiofemoral joint flexed, the PCL prevents the tibia from being pulled posteriorly .

14. Ligaments

15. Menisci Meniscus- is a crescent shaped fibrocartilaginous structure that, in contrast to articular discs, only partly divides a joint cavity. Medial meniscus Lateral meniscus

16. Bursae Bursae - A closed sac lined with a synovial membrane and filled with fluid, usually found in areas subject to friction, such as where a tendon passes over a bone. infrapatellar bursa suprapatellar bursa prepatellar bursa

17. Muscles of the knee joint Biceps femoris Semomembranosus Semitendinosus Gracilis Satorius Tensor Fascia Lata Popliteus Gastrocnemius Plantaris Rectus femoris Vastus medialis Vastus lateralis Vastus intermedius

18. Muscles \Muscle Origin Insertion Nerve Action Popliteus lateral surface of lateral condyle of femur and lateral meniscus Posterior surface of the tibia. Tibial nerve L4-S1 Assist knee flexion Gastrocnemius Lateral head: lateral aspect of lateral condyle of femur. Medial head: popliteal surface of femur, superior to medial condyle calcaneus with calcaneal tendon tibial nerve (S1,S2) plantairflexion ankle, flexion knee Plantaris inferior end of lateral supracondylar line of femur tuber calcanei tibial nerve (L5,S1) assists gastrocnemius in plantarflexion ankle and flexing knee

19. Muscles Origin Insertion Nerve Action Rectus Femoris anterior inferior iliac spine, ilium superior to acetabulum base of patella, tibial tuberosity femoral nerve (L2,L4) knee extension, flexion hip. Vastus Medialis interthrochanteric line and linea aspera of femur base of patella, patellar ligament to tibial tuberosity femoral nerve (L2,L4) . knee extension Vastus Lateralis intertrochanteric line, greater trochanter , linea aspera . base of patella, lateral side of quadriceps femoris tendon. femoral nerve (L2, L3, L4) extension of the knee Vastus Intermedius anterior and lateral surfaces of body of femur base of patella, patellar ligament to tibial tuberosity femoral nerve (L2,L4) . knee extension. Biceps femoris long head: ischial tuberosity . short head: lower half of the linea aspera , and lateral condyloid ridge. I: head of the fibula and lateral condyle of the tibia Sciatic nerve Knee flexion

20. Muscles Origin Insertion Nerve Action Semitendinosus Ischial tuberosity Medial surface of tibia Sciatic nerve Knee flexion Semimembranosus Ischial tuberosity Medial condyle of tibia Sciatic nerve Knee flexion Gracilis Ischiopubic ramus Upper part of the medial surface of the body of tibia. Obturator nerve Knee flexion Satorius Anterior superior illiac spine of the pelvic bone. Anteromedial surface of the upper tibia. Femoral nerve. Knee flexion. Tensor Fascia lata anterior superior iliac spine, anterior part iliac crest. iliotibial tract attaches to lateral condyle of tibia. superior gluteal nerve (L4,L5) . Assists in knee flexion.

21. Muscles

22. Innervations The muscles of the knee are supplied by the lumbosacral plexus; S1, S2, L2, L3,L4 and L5. The nerves are; Obturator nerve Tibial nerve Femoral nerve Sciatic nerve.

23. Arterial and venous supply Arteries of the knee The main arteries supplying the knee region are; femoral, popliteal , anterior tibial and posterior tibial arteries. Although the popliteal artery is deep in the popliteal fossa , the popliteal pulse can still be felt but the knee has to be bent and the person still has to press deep into the fossa . Veins of the knee There are deep and superficial veins. The names of the deep veins are the same as the names of the artery they accompany. There are two important superficial veins: the great and lesser saphenous veins. The great saphenous is often used in coronary bypass operations as it has thicker walls than most veins and therefore it can substitute for an artery. ( Removal of this vein does not cause a problem as there are still the deep veins to return the blood to the heart).

24. Artery and Veins

25. Movements Knee; Performs one degree of movement. Flexion and Extension Occurs in sagital plane in the frontal axis

26. Movements-Kinematics Osteokinematic The knee produces only to major osteokinematic movements. These are primarily the; Flexion- 130-140 degrees Extension- produces at 0 degrees whilst some go into -5 degree of hyperextension, beyond -5 degree it is described as genu recurvatum .

27. Movements- Osteokinematics Extension During, the quadriceps muscles contract pulling on the quadriceps tendon, which in turn pulls on the patella via the patellar tendon causing an extension of the knee. Flexion On the posterior side of the knee the hamstring group of muscles contract pulling on the tendons associated with the hamstring, pulling on the tibia, which causes the flexion of the knee.

28. Movements Arthrokinematic Whenever there is a bending of the knee, the femoral condyles come into flexion producing posterior rolling and anterior sliding.

29. Movements Arthrokinematics If suppose there is an extension of the knee, there is an anterior rolling of the femoral condyles and a posterior sliding occurs to bring knee into extension.

30. Pathologies Common Knee Injuries Meniscal Ligament Tendon Dislocation Fracture

31. Pathologies Rheumatoid arthritis Osteoarthritis Patella chondromalacia Common Knee Conditions

32. Injury /Pathology Physiotherapy Diagnosis Physiotherapy Treatment and Rehabilitation Application of Biomechanics and Kinesiology

33. Medial Collateral Ligament Tear Knee Ligament Stability Tests - Adduction Test/Valgus Stress Test) The knee is stabilized by: Ligament Menisci Shape and congruency of the articular surfaces Muscles The ligaments ensure functional congruency by guiding the femur and tibia and limiting the space between them. Ligament injuries lead to functional impairment of the knee with instability. Knee ligament stability tests can help to identify and differentiate these instabilities. Abnormal directions of motion can be divided into three categories: 1. Direct instability in a single plane 2. Rotational instability 3. Combined rotational instability Medial Collateral Ligament and medial stability is assessed in 20° of flexion and in full extension. In 20°of flexion, the posterior capsule is relaxed. Screw-home mechanism Interlocking of femoral and tibial condyles. Applying a valgus stress in 15-20 flexion evaluates the medial collateral ligament alone as the primary stabilizer. Full extension prevents medial opening as long as the posterior capsule and posterior cruciate ligament are intact, even if the medial collateral ligament is torn. Example 1. Physiotherapy Diagnosis (Special Tests)

34. Example 2. Pathology, Physiotherapy Treatment and Rehabilitation Osteoarthritis – Total Knee Arthroplasty Replacement Ascending Stairs The actual degree of knee flexion required to ascend stairs is determined not only by the height of the step but also by the height of the patient. For the standard step approximately 65 of flexion will be required. In climbing stair, lever arm can be reduced by leaning forward. The tibia is maintained relatively vertical, which diminishes the anterior subluxation potential of the femur on the tibia.

35. Cont.. Descending stairs In standard step 85 of flexion is required: The tibia is steeply inclined toward the horizontal, bringing the tibial plateaus into an oblique orientation. The force of body weight will now tend to sublux the femur anteriorly. This anterior subluxation potential will be resisted by the patellofemoral joint reaction force and the tension which develops in the posterior cruciate ligament.

36. Cont.. In the absence of a posterior cruciate ligament only the collateral ligaments are available to assist the patellofemoral joint reaction force in providing anterior-posterior stability Many patients with arthritis will report difficulty descending stairs normally, this will also be true after total knee replacement. A simple rehabilitation training is to have them descend either sideways or backward which is biomechanically the equivalent of ascending the stairs with its decreased mechanical and range of motion demands.

37. Summary The knee joint is classified as a synovial uniaxial hinge joint. The muscles of the knee; that primarily contributes to movements produced are the hamstrings and quadriceps. There two meniscus; medial and lateral meniscus Also present at the knee is the bursae , there three types; infrapatellar , suprapatellar and prepatellar bursae .

38. Summary The articular surfaces of the knee are the; condyles of the femur and tibia and the posterior surface of the patellar. The ligaments provides stability, there are four types; the medial collateral, lateral collateral, anterior cruciate and posterior cruciate ligaments. The nerve innervations at the muscles of the knee joints are; obturator , femoral, tibial and the sciatic nerve.

39. Summary The arteries supplying the knee are; femoral, popliteal , anterior tibial and posterior tibial arteries. The veins at the knee region are the great and lesser saphenous veins. The movements; flexion and extension ( osteokinematics ) & sliding and rolling ( arthrokinematics ). The knees abnormality results from injuries and diseases affecting its structures.

40. References American Academy of orthopedic surgeon, Ortho info, www.aaos.com , 28 th /04/2015, P.K Levangie et al, Joint structure and function: A comprehensive analysis (2005), 4 TH edition, F.A. Davis Company, Philadelphia, USA Images from PY107 Anatomy: Miss Girey’s Presentation and from Miss Nilam’s Orthopedic PY209 presentations.

41. Reference D. Knudson, Foundamentals of Biomechanic (2007), springer science, New York, USA. Joseph H., KnutzenM ., Biomechanical basis of human movement, 2003 LevangieP , NorkinC ., Joint structure & function, a comprehensive analysis,5thed. Philadelphia, FA Davis Company. 2011. Premkumar K. The Massage Connection: Anatomy and Physiology. Baltimore: Lippincott Williams & Wilkins, 2004.

42. References Joseph H., KnutzenM ., Biomechanical basis of human movement, 2003 LevangieP , NorkinC ., Joint structure & function, a comprehensive analysis,5thed. Philadelphia, FA Davis Company. 2011. Premkumar K. The Massage Connection: Anatomy and Physiology. Baltimore: Lippincott Williams & Wilkins, 2004.

43. The End Questions????????