1. KNEE JOINT
It is the largest and most complicated joint in the body.

2. FUNCTIONS 1. Weight bearing.
2.Essential for daily activities: standing walking & climbing stairs.
3.The main joint responsible for sports: running, jumping , kicking etc.

3. ARTICULATING BONES
1. Lateral and medial articulations between the tibial condyles and their cartilaginous menisci and the corresponding femoral condyles.

4. ARTICULATING BONES
2. Intermediate articulation between the patella and femur.

5. THE FEMORAL CONDYLES The medial extends further forwards .
The lateral is more oval.
The condyles are convex from front to back.

6. TIBIAL CONDYLES (PLATEAUS) are flat .
The medial is oval The lateral is round.
The articular surfaces are covered with hyaline cartilage.

7. TYPE
A synovial joint of the hinge variety between the medial and lateral condyles of the femur and the corresponding tibial condyles with some degree of rotation.

8. TYPE
A synovial joint of the plane gliding variety between the patella and the patellar surface of the femur.

9. CAPSULE It is absent Anteriorly. It is Replaced by :
Quadriceps femoris tendon.
Patella.
Ligamentum patellae.

10. CAPSULE Posteriorly : (a) Superior :
Attached proximal to the articular margins of the femoral condyles and to the intercondylar fossa.
It is deficient above the lateral condyle for the passage of tendon of popliteus.

11. CAPSULE
(b) Inferior :
Attached to the tibia EXCEPT when the tendon of Popliteus crosses the bone.

12. EXTRACAPSULAR LIGAMENTS
1. Ligamentum Patellae
It is the inter mediate part of the tendon of quadriceps femoris .It is supported by the patellar retinaculi (expansions from the vasti)
They strengthen the capsule on each side.

13. 2. TIBIAL (MEDIAL) COLLATERAL
A flat band.
Attachment:
Above to the medial condyle of the femur.
Below to the medial surface of the shaft of the tibia.
Firmly attached to the medial meniscus.

14. 3. LATERAL (FIBULAR) COLLATERA
Cord like.
Attachment :
Above : lateral condyle of the femur.
Below : head of the fibula.
Separated from the lateral meniscus by the tendon of popliteus.

15. 4. OBLIQUE POPLITEAL An expansion of the Semimembranosus.
It strengthens the capsule posteriorly.

16. INTRA CAPSULAR STRUCTURES
1. CRUCIATE LIGAMENTS.
2. MENISCI.
3. TENDON OF POPLITEUS.

17. CRUCIATE LIGAMENTS
They are the main bond between the femur and tibia throughout the joint’s movements.
They Cross each other within the joint cavity.
They are named Anterior and Posterior according to their tibial attachments.

18. ANTERIOR CRUCIATE Tibial attachment : Anterior intercondylar area.
Course :
Upward, backward and laterally.
Femoral attachment:
Posterior part of medial surface of the lateral condyle.

19. ANTERIOR CRUCIATE FUNCTION
Prevent posterior displacement of the femur on the tibia and the tibia from being pulled anteriorly when the knee joint is flexed.
It is taught in hyper extension.

20. POSTERIOR CRUCIATE Tibial attachment : posterior inter condylar area.
Direction:
upward, forward and medially.
Femoral attachment:
Anterior part of the lateral surface of the medial condyle.

21. POSTERIOR CRUCIATE Function:
prevents anterior displacement of the femur on the tibia and the tibia from being pulled posteriorly when the knee joint is flexed.
It is taught in hyper flexion.

22. MENISCI C shaped sheets of fibro cartilage.
The peripheral border is thick and attached to the capsule.
The inner border is thin and concave and forms a free edge.

23. MENISC
The upper concave surfaces are in contact with the femoral condyles.
The lower flat surfaces are in contact with the tibial condyles.

24. MENISCI Functions : 1. Deepen the tibial articular surfaces.
2. Act as cushions between the two bones.

25. MEDIAL MENISCUS Crescentic in shape.
More liable to injury due to its attachment to the medial collateral ligament and to the capsule.
It is relatively immobile.

26. LATERAL MENISCUS More rounded in shape.
Its anterior and posterior ends lie within the ends of the medial meniscus.
Posteriorly it is separated from the fibular collateral ligament by the tendon of popliteus.
Less liable to injury.

27. INJURY OF THE MENISCI
The menisci are frequently injured especially in footballers and cricketers.
The medial is torn three times more often than the lateral.
The injury is produced by the rotation of the femur on the tibia or the reverse with the knee joint partially flexed and carries the weight of the body.

28. INJURY OF THE MENISCI
The torn part of the meniscus is wedged between the tibial and femoral condyles.
No further movement is allowed and the joint is kept locked.

29. SYNOVIAL MEMBRANE
It lines the lateral and medial parts of the capsule.
Anteriorly :
It forms the supra patellar bursa.
It is attached to the inter condylar area of the tibia and to the lateral and medial borders of the patella.

30. SYNOVIAL MEMBRANE
It is reflected backward from the posterior surface of the ligamentum patellae to form the Infrapatellar fold.
The free borders of the fold are the Alar folds.
The space between these folds contains fat (Infrapatellar pad of fat).

31. SYNOVIAL MEMBRANE Posteriorly :
It Passes out to surround the cruciate ligaments.
It is continuous with the surface layer of the menisci.
It covers the tendon of popliteus and forms a bursa around it (popliteal bursa).
It forms the semimembranosus bursa.

32. ANTERIOR BURSAE They are four : 1. Suprapatellar :
It is 3 fingerbreadths above the patella.
Always continuous with the joint cavity.
Held in position by the articularis genus muscle.
Accumulation of fluid in the joint causes excees fluid in the bursa leading to floating patella.

33. ANTERIOR BURSAE 2. Prepatellar
If enlarged it causes (House Maid’s) bursa.

34. ANTERIOR BURSAE 3.Superficial Infrapatellar. (PARSON’S bursa
4.Deep Infrapatellar.

35. POSTERIOR BURSAE (6) 1. POPLITEAL
Always continuous with the joint cavity.
2.SEMIMEMBRANOSU
Usually communicates with the joint cavity.
3 & 4. GASTROCNEMIUS
Around sartorius,gracilis and semitendinosus.

36. MOVEMENTS 1. FLEXION Hamstrings( supplied by the sciatic nerve).
Assisted by sartorius, popliteus and gracilis.
Checked by back of calf in contact with the back of the thigh.

37. MOVEMENTS
2. EXTENSION
Quadriceps Femoris (supplied by the femoral nerve.)
Limited by tension of the cruciate and collateral ligaments.

38. MOVEMENTS
3. ROTATION
(A) MEDIAL: Sartorius, gracilis and semitendinosus.
(B) LATERAL : Biceps femoris

39. NERVE SUPPLY
Femoral.
Obturator.
Sciatic.
Common peroneal.
Tibial.

40. UNLOCKING At the commencement of Flexion of the extended knee. Aim :
To slack the ligaments especially the cruciate.
FEMUR: Lateral rotation (the foot is on the ground)
TIBIA: Medial rotation.
Muscle: POPLITEUS

41. LOCKING The joint assumes the position of full extension.
It becomes a rigid structure.
The menisci are compressed between the tibial and femoral condyles.
Tightening of all the major ligaments.
The femur is medially rotated on the tibia.

42. RELATIONS
Anterior :
Prepatellar bursa.

43. RELATIONS Posterior : Boundaries and contents of Popliteal Fossa.
Medial :
SGS muscles.
Lateral :
Biceps femoris and common peroneal nerve.

44. STABILITY
1. Muscles :
QUADRICEPS particularly the inferior fibers of the vasti lateralis and medialis.
Many sport injuries can be preventable through appropriate training and conditioning of the muscle.

45. STABILITY
2. Ligaments :
The knee joint can function well following a ligamentous strain if the quadriceps is intact.

46. INJURY OF THE JOINT TRIAD OF INJURY 1. Medial collateral ligament.
2. Medial meniscus.
3. Anterior cruciate ligament.
The joint becomes swollen because it is filled with blood (hemarthrosis).

47. ANTERIOR CRUCIATE INJURY
Tear of the anterior cruciate ligament is more common than the posterior.
The tibia can be pulled excessively forward on the femur

48. POSTERIOR CRUCIATE INJURY
The tibia can be pulled excessively backward on the femur.

49. INJURY OF THE CRUCIATE LIGAMENTS
Management :
Knee is kept immobilized in slight flexion.
Active physiotherapy of the quadriceps femoris at once.
Operative repair (incase of torn of the capsule and collateral ligaments).

50. ANKLE JOINT TYPE Hinge synovial ARTICULATING BONES
1. Lower end of the tibia
2. Two malleoli.
3. Body of the talus.
4. The inferior transverse tibiofibular ligament deepens the socket for the body of the talus.

51. ANKLE JOINT CONT’D CAPSULE
Encloses the joint and attached near the articular margins except anteriorly where anteriorly it is attached to the neck of the talus in front of the articular edge.
It is thin in front and behind.
Posteriorly it fuses with the inferior transverse tibiofibular ligament.

52. SYNOVIAL MEMBRANE Lines the capsule.
Reflected anteriorly on to the neck of the talus as far as the articular cartilage.
May extend a short distance between the tibia and fibula.

53. LIGAMENTS MEDIAL( DELTOID)
Attached by its apex to the tip of the medial malleolus.
Composed of deep and superficial fibers.
DEEP FIBERS
Attached to the non articular area on the medial surface of the body of the talus.
SUPERFICIAL FIBERS
Attached to

54. LIGAMENTS CONT’D Sustentaculum tali.
Plantar calcaneonavicular ligament.
Medial side of talus.
Tuberosity of navicular bone.

55. LATERAL LIGAMENT
Weaker than the medial.
It consists of three bands
1. ANTERIOR TALOFIBULAR
Between the lateral malleolus and the lateral surface of the talus.
2. CALCANEOFIBULAR
From the tip of the lateral malleolus to the lateral surface of the calcaneum.

56. 3. POSTERIOR TALOFIBULAR
Between the lateral malleolus and the posterior tubercle of the talus.

57. STABILITY OF THE JOINT 1. Shape of the articulating bones.
2. Strength of the ligaments.
3.The surrounding tendons.

58. RELATIONS

59. MOVEMENTS DORSIFLEXION
Tibialis anterior, extensors of the digits and big toe, peroneus tertius.
LIMITED BY
Tension of tendo calcaneus.
Posterior fibers of the medial ligament.
Calcaneofibular ligament.

60. PLANTAR FLEXION
Tibialis posterior, peroneus (longus and brevis) gastrocnemius.
LIMITED BY
Tension of opposing muscles.
Anterior fibers of the medial ligament.
Anterior talofibular ligament.