1. Joints of the lower limb Hip joint Knee joint Ankle joint

2. Hip joint it is a synovial joint of ball and socket type, the joint formed between the head of the femur and the acetabulum the articular surface of which is horseshoe shaped and is deficient inferiorly at the acetabular notch.

3. The cavity of the acetabulum is deepened by the presence of a fibrocartilaginous rim called the acetabular labrum, the labrum is bridges across the acetabular notch by the transverse acetabular ligament.

4. The strength and stability of the joint depend on : 1- Depth of the acetabulum which increased by the labrum acetabulae. 2-The strength of the ligaments and the surrounding muscles.

6. The fibrous capsule which surrounds the joint attached to the margin of the acetabulum and transverse ligament proximally. Distally attached to the intertrochantric line and greater trochanter anteriorly and intertrochantric crest posteriorly. The fibrous capsule is lined by the synovial membrane.

7. Ligaments of the joint 1- Iliofemoral ligament is a strong ligament lie in the front of the joint. it is inverted Y shaped. 2-Pubofemoral ligament it is triangular ligament lie in the lower anterior part of the capsule. 3-Ischiofemoral ligament it is spiral in shape lie posteriorly.

8. iliofemoral ligament

9. Ischiofemoral ligament

10. 4-The transverse acetabular ligament it converts the notch into a tunnel through which the blood vessels and nerves enter the joint. 5-Ligaments of the head of the femur it is flat attached to the pit on the head of the femur and by its base to the transverse acetabular ligament.

12. Movement of the joint 1-flexion which is very free. 2-Extension is extremely restricted by the iliofemoral ligament. 3-Abduction is restricted by the pubofemoral ligament. 4-Adduction is restricted by the lateral portion of the iliofemoral ligament. 5-Medial rotation tightens the ischiofemorall ligament. 6-Lateral rotation is limited by the pubofemoral ligament and the lateral part of the iliofemoral ligament.

13. Blood supply of the joint 1-Ascending branches of lateral and medial circumflex femoral artery. 2-Acetabular branches of the obturator and medial circumflex arteries. 3-Branches of the superior and inferior gluteal artery.

14. Nerves of the joint 1-Nerve to quadratus femoris. 2-The femoral nerve through nerve to rectus femoris. 3-Anterior division of the obturator nerve.

15. The knee joint It is a synovial joint of the hinge type, it is unstable joint but this overcome by certain mechanism: 1- expansion of the upper end of the tibia and lower end of the femur. 2- Presence of the strong collateral ligament and tendons. 3- Strong capsule. 4- Presence of the intra-articular ligaments.

17. The articular surface of the femur is the condyles while the articular surface of the tibia is the tibial condyles which is deepen by the mensci. On the front of the joint the capsule is absent permitting the synovial membrane to pouch upward beneath the quadriceps tendon forming the suprapatellar bursa.

18. The capsule of the joint attached to the condyles of the femur superiorly and to the tibial condyles and the margin of the mensci inferiorly.

19. Ligaments of the joint 1- lateral and medial patellar retinacula these are extensions from the tendons of the lateral and medial vasti ms. which run along the sides of the pattela. 2-Iliotibial tract attached laterally to the oblique line in the lateral condyle of the tibia and to the head of the fibula. 3-The ligamentum patellae which is a continuation of the quadriceps femoris tendon run on the patella to reach the tibial tuberosity.

21. 4-Oblique popliteal ligament it is the posterior reinforcement of the capsule of the joint and it is extension from the tendon of the semimembrenosus m. 5-Arcuate popliteal ligament arise from the back of the head of the fibula and runs medially over the popliteus m.

23. 6-Collateral ligament they are tibial and fibular collateral ligaments. They are very strong ligaments. Tibial collateral ligament: extends from the medial epicondyle of the femur to the medial condyle of the tibia. Fibular collateral ligament: it is cord like ligament extends from the lateral epicondyle of the femur to the head of the fibula.

26. cruciate ligaments 7-these are two ligaments lie inside the joint cross each other. Anterior cruciate ligament extends from in front of condylar eminence of tibia to the posterior part of the lateral condyle of the femur it passes upward and backwards.

27. Posterior cruciate ligament passes upwards and forwards from the posterior part of the tibial intercondylar area to the lateral surface of the medial condyle of the femur. It prevents anterior displacement of the femur on the tibia.

29. Mensci These are a C shaped plates of fibrocartilage which deepen the articular surface of the tibial condyles, they are medial and lateral they attached to : 1-intercondylar area by their horns. 2-The margins of the tibial condyles.

30. The two mensci linked together anteriorly by transverse ligaments of the knee. The lateral meniscus is circular to keep the spherical lateral condyle of the femur. The medial meniscus is elongated anteroposteriorly to keep the shape and movement of the medial condyle of the femur.

32. Synovial membrane It lines all the structures which forms the wall of the cavity of the knee joint except the articular surfaces of the bones, mensci and the posterior part of the fibrous capsule where the synovial membrane turns forwards to enclose the cruciate ligaments.

34. Anastomosis around the knee joint Formed by 8 arteries these are: 1-2 lateral and 2 medial genicular arteries from the popliteal artery. 2-Descending genicular artery from the femoral artery. 3-Anterior and posterior tibilal recurrent arteries. 4-Genicular artery from the lateral circumflex artery. The middle genicular artery play a little part since it supply the structures within the capsule of the joint.

36. Nerves of the joint 1-femoral nerve through nerve of vasti muscles. 2-Common peroneal nerve through superior and inferior lateral genicular nerves. 3-Tibial nerve through superior and inferior medial genicular nerves. 4-Obturator nerve.

37. Movement of the joint Flexion through biceps, semitendinosus and semimembranosus; assisted by the sartorius, gracilis and popliteus. Extension by quadriceps femoris m. Rotation: medial rotation by sartorius, gracilis and semitendinosus. Lateral rotation by biceps femoris m.

38. Ankle joint This is a hinge type of joint between the trochlea of the talus with the distal end of the tibia and medial malleolus medially and the lateral surface of the body of the talus with the lateral malleolus laterally.

39. It is strong and stable joint by: 1-The powerful ligament and tendons. 2-The insertion o the trochlea into the deep socket between medial and lateral malleol i.

41. Ligaments of the joint 1-medial (Deltoid) ligament. It is a very strong ligament radiates from the distal border of the medial malleolus to the medial side of the talus, to the medial surface of the calcaneus, to the navicular bone and to the neck of the talus.

42. Deltoid ligament

43. 2-Lateral ligament consists of 3 bands, the anterior and posterior are thickenings of the fibrous capsule, the anterior one is the anterior talofibular ligament and the posterior is the posterior talofibular ligament. And the calcaneofibular ligament extend from the distal end of the lateral malleolus to the lateral surface of the calcaneus.

44. Lateral ligament

45. Anastomois around the ankle joint 1-on the lateral side the lateral malleolar branch of the anterior tibial artery and the lateral tarsal branch of the dorsalis pedis artery anastomosed with the perforating branch and terminal branches of the peroneal artery.

46. 2-On the medial side the medial malleolar artery anastomosed with the medial calcanean branch of the posterior tibial artery. The posterior tibial artery itself also anastomosed with the peroneal artery posterior to the ankle joint.

47. Nerve supply of the joint from the tibial nerve and the lateral branch of the deep peroneal nerve. Movements of the joint are the dorsiflexion and planterflexion. Dorxiflexion is through the muscles of the anterior compartment of the leg; while the planteflexion through the muscles of the superficial compartment of the back of the leg. The maximum stability of the joint is achieved in dorxiflexion.