Posterior compartment of thigh

2. Posterior compartment of thigh Dr. Zeenat Zaidi

3. Medial inter-muscular septum Femur Linea aspra Lateral inter-muscular septum

4. Cutaneous Nerves • Mainly supplied by the posterior cutaneous nerve of the thigh, a branch of the sacral plexus • It leaves the gluteal region by emerging from beneath the lower border of the gluteus maximus muscle • Descends on the back of the thigh • In the popliteal fossa it pierces the deep fascia • Gives off numerous branches to the skin on the back of the thigh and the upper part of the leg

5. Superficial Veins & Lymphatics • Veins from the upper part curve around the medial and lateral aspects of the thigh and ultimately drain into the great saphenous vein. • Veins from the lower part join the small saphenous vein in the popliteal fossa. • Lymph from the skin and superficial fascia on the back of the thigh drains upward and forward into the vertical group of superficial inguinal lymph nodes

6. Contents • Muscles: • Hamstrings: • Semitendinosus • Semimembranosus • Biceps Femoris • Adductor magnus • Vessels: • Perforating branches of profundafemoris artery & accompanying veins • Nerves: • Sciatic nerve (tibial & common peroneal nerves) • Lymph nodes & lymphatics

7. Biceps femoris • Origin: • Long head: Ischial tuberosity • Short head:Linea aspera & lateral supracondylar ridge of shaft of femur • Insertion: Head of fibula • Nerve supply: • Long head: Tibial portion of sciatic nerve • Short head: Common peroneal portion of sciatic nerve • Action: • Extends thigh at hip joint (long head) • Flexes and laterally rotates leg at knee joint Long head Short head

8. Semitendinosus • Origin: Ischial tuberosity • Insertion: Upper part of medial surface of shaft of tibia. • Sends a fibrous expansion upward and laterally, called the oblique popliteal ligament which reinforces the capsule on the back of the knee joint • Nerve supply:Tibial portion of sciatic nerve L5; S1, 2 • Action: • Flexes and medially rotates leg at knee joint • Extends thigh at hip joint

9. Semimembranosus • Origin: Ischial tuberosity • Insertion: Medial condyle of tibia • Nerve supply: Tibial portion of sciatic nerve L5; S1, 2 • Action: • Flexes and medially rotates leg at knee joint • Extends thigh at hip joint

10. Adductor Magnus(Hamstring portion) • Origin: Ischial tuberosity • Insertion: Adductor tubercle of femur • Nerve supply: Tibial portion of sciatic nerve L2, 3, 4 • Action: Extends thigh at hip joint

11. Blood Supply • Supplied richly by four perforating branches of the profunda femoris artery • The profunda femoris vein drains the greater part of the blood from the compartment.

12. Sciatic Nerve • A branch of the sacral plexus (L4, 5; S1, 2, 3) • Leaves the gluteal region and descends in the midline of the thigh • Overlapped posteriorly by the adjacent margins of the biceps femoris and semimembranosus muscles • Lies on the posterior aspect of the adductor magnus muscle • In the lower third of the thigh it ends by dividing into the tibial and common peroneal nerves • Occasionally, the sciatic nerve divides into its two terminal parts at a higher level

13. Branches • Tibial nerve, a terminal branch of the sciatic nerve, enters the popliteal fossa • Common peroneal nerve, a terminal branch of the sciatic nerve, enters the popliteal fossa on the lateral side of the tibial nerve. • Muscular branches to long head of biceps femoris, semitendinosus, semimembranosus, and hamstring part of the adductor magnus. These branches arise from the tibial component of the sciatic nerve and run medially to supply the muscles

14. PoplitealFossa

15. PoplitealFossa Diamond-shaped Intermuscular space Situated at the back of the knee Most prominent when the knee joint is flexed

16. Boundaries • Superomedial • Semitendinosus • Suprolateral • Biceps femoris • Inferomedial • Gastrocnemius (medial head) • Inferolateral • Gastrocnemius (lateral head)

17. Floor: posterior surface of lower end of femur, capsule of knee joint (oblique popliteal ligament), popliteus muscle Roof:skin, fascia, small saphenous vein

18. Contents • Popliteal artery • Veins: • Popliteal vein • Small saphenous vein • Nerves: • Common peroneal and tibial nerves • Posterior cutaneous nerve of the thigh • Genicular branch of the obturator nerve • Connective tissue • Lymph nodes

19. Popliteal Artery • Continuation of the femoral artery • Enters the fossa through an opening in the adductor magnus (adductor hiatus) • Deeply placed in the fossa. Pulsation can be felt in flexed knee • Ends at the level of the lower border of the popliteus muscle by dividing into anterior and posterior tibial arteries.

20. Relations • Anteriorly: Popliteal surface of the femur, knee joint, and popliteus muscle • Posteriorly: Popliteal vein and tibial nerve, fascia, and skin • Branches • Muscular branches • Articular branches to the knee.

21. Popliteal Vein • Formed: • by the union of the venaecommitantes of the anterior and posterior tibial arteries • at the lower border of the popliteus muscle • on the medial side of the popliteal artery. • Ascends in the fossa, crosses behind the popliteal artery so that it comes to lie on its lateral side. • Passes through the opening in the adductor magnus to become the femoral vein.

22. Tributaries • Veins that correspond to branches of the popliteal artery • Small saphenous vein

23. Arterial Anastomosis Around the Knee Joint • A profuse anastomosis is formed around the knee joint, between the branches of the: • femoral artery • popliteal artery • Anterior & posterior tibial arteries • It plays an important role to compensate for the narrowing of the popliteal artery, which occurs during extreme flexion of the knee

24. Popliteal Lymph Nodes • Five or six lymph nodes • Embedded in the fatty connective tissue of the popliteal fossa • Afferents: • Superficial lymph vessels from the lateral side of the foot and leg • Lymph from the knee joint • Deep lymph vessels accompanying the anterior and posterior tibial arteries • Efferents: Inguinal lymph nodes

25. Tibial Nerve • The larger terminal branch of the sciatic nerve • Arises in the lower third of the thigh. • Runs downward through the popliteal fossa, lying first on the lateral side of the popliteal artery, then posterior to it, and finally medial to it. • The popliteal vein lies between the nerve and the artery throughout its course. • The nerve enters the posterior compartment of the leg by passing beneath the soleus muscle.

26. Branches • Cutaneous: • Sural nerve • Muscular: • to both heads of gastrocnemius , plantaris, soleus, and popliteus • Articular: • to knee joint

27. The sural nerve descends between the two heads of the gastrocnemius muscle Is usually joined by the sural communicating branch of the common peroneal nerve Gives numerous small branches to supply the skin of the calf and the back of the leg. Accompanies the small saphenous vein behind the lateral malleolus Is distributed to the skin along the lateral border of the foot and the lateral side of the little toe.

28. Common Peroneal Nerve • Smaller terminal branch of the sciatic nerve • Arises in the lower third of the thigh • Runs downward through the popliteal fossa, closely following the medial border of the biceps muscle • Leaves the fossa by crossing superficially the lateral head of the gastrocnemius muscle

29. passes behind the head of the fibula • winds laterally around the neck of the bone • pierces the peroneus longus muscle, and • Divides into two terminal branches: • Superficial peroneal nerve • Deep peroneal nerve

30. Left foot drop As the nerve lies on the lateral aspect of the neck of the fibula, it is subcutaneous and can easily be rolled against the bone. At this site, it is extremely vulnerable to direct trauma or is involved in fractures of the upper part of the fibula Injury to the common peroneal nerve causes footdrop

31. Branches • Cutaneous: • Sural communicating branch runs downward and joins the sural nerve • Lateral cutaneous nerve of the calf supplies the skin on the lateral side of the back of the leg • Muscular branch to the short head of the biceps femoris muscle, which arises high up in the poplitealfossa • Articularbranches to the knee joint

32. Thank You & Good Luck