Posterior compartment of thigh

Discussion about posterior compartment of thigh.
Also includes discussion about sciatic nerve and popliteal fossa.

1. Posterior compartment of
thigh
Dr Rajiv Ranjan
RIMS, RanchiDr Rajiv Ranjan

2. POSTERIOR COMPARTMENT
•True “Hamstrings”
•Cross both the hip and the knee joint
•Involved in knee flexion and hip extension
•Semitendinosus,
•Semimembranosus,
•Biceps f
(long head)
•Adductor ma
gnus???
•Blood supply: perforating branches
pr
ofundafemorisA (1
st
perforating A)
•Innervation : t ibialdivision of sciatic N (L5, S1&S2)Dr Rajiv Ranjan

3. Muscles
OverviewDr Rajiv Ranjan

4. Semitendinosus
•Origin –is tuberosity
•Insertion –a
s pes anserinus
•Vascularity –me
dial circumflex
femoral A& first perforating A
•Innervation –T
ibialdiv. of sciatic N
•Distal Semi
tendon is one
of the tendons that can be used in
the surgical procedure of ACL
reconstructionDr Rajiv Ranjan

5. Semimembranosus
•Origin –i
•Insertion – Ba
ck of Medial tibial
condyle
•Vascular supply –pe
rforating
arteries usually 1
st
or 4
th
•Innervation –Sc iatic nerve, L5, S1
and 2, through its Tibialdivision.Dr Rajiv Ranjan

6. Biceps femoris
•Origin –
long head – is
chialtuberosity
short head – la
teral lip of lineaaspera
& lateral supracondylar line
•Insertion –l
ateral side of the head of
the fibula
•Vascular supply –fi
rst and second
perforating arteries
•Innervation –s
ciatic nerve, L5, S1 and
2,
•long head  t
ibialdivision
•short he
common peroneal
divisionDr Rajiv Ranjan

7. Adductor Magnus
Hamstring part
O : Ischial tuberosity
I : Adductor tubercle & medial supracondylar
line
Nerve supply : Tibialdiv. of sciatic NDr Rajiv Ranjan

8. Schematic
of attachmentsDr Rajiv Ranjan

9. Actions of Hamstrings
•Acting from above, the posterior
f
emoral muscles flex the knee
•Acting from below, they extend the hip
j
oint
•knee semi-f
femoris is a
lateral rotator and semimembranosus
and semitendinosus are medial
rotators of the leg on the thigh at the
knee
•Hip –e

rotator and semimembranosus and
semitendinosus are medial rotators of
the thighDr Rajiv Ranjan

10. Testing & surface LocalizationDr Rajiv Ranjan

11. Applied
Seen among athletes
Biceps femorismore proneDr Rajiv Ranjan

12. Vascularity Dr Rajiv Ranjan

13. Dissection
OverviewDr Rajiv Ranjan

14. Sciatic nerve
The sciatic nerve is 2 cm wide at its origin (thickest)
2 components
Tibial–L

Common f
–L4, 5, S1, 2 dorsal
div. of sacral plexus
supplied by a branch from the inferior gluteal k/a
artery of the sciatic nerveDr Rajiv Ranjan

15. Sciatic nerve : course
Leaves the pelvis via the greater sciatic foramen below
p
iriformis
descends between the greater trochanter and ischial
tu
berosity
Superiorly it lies deep to gluteus maximus, resting first
o
n the posterior ischial surface with the nerve to
quadratus femorisbetween them.
It then crosses posterior to obturator internus, the
g
emelliand quadratus femoris
Q f
separates it from obturator externus and the
hip joint
It is accompanied medially by the posterior femoral
c
utaneous nerve and the inferior gluteal artery.
More distally it lies behind adductor m
agnusand is
crossed posteriorly by the long head of biceps femorisDr Rajiv Ranjan

16. Surface marking
•Take 3 pthem c̄lateral convexity
•1
st
: 2.5 cm lateral to the line joining PSIS & IT
•2
nd
: midpoint of IT & G. trochanter
•3
rd
: apex of popliteal fossa at the junction of
upper 2/3
rd
& lower 1/3
rd
of the back of thigh
•Along the back of the thigh it divides into the
t
ibialand common peroneal(fibular) nerves
at a varying level proximal to the knee
•Common site is at the junction of the middle
a
nd lower thirds of the thigh, near the apex
of the popliteal fossaDr Rajiv Ranjan

17. Branches
•Articular branches arise from the
u
pper part of the nerve and supply
the hip-joint
•Muscular branches to : biceps
f
emoris, semitendinosus,
semimembranosus, and adductor
magnus
•Terminal b
: Tibial& Common
Fibular NDr Rajiv Ranjan

18. Applied
•Most c damage misplaced gluteal injections
•Other causes include p
elvic disease and severe trauma to the hip
•Paralysis o
the hamstrings and all the muscles of the leg and foot (foot drop)
•sensory loss below the knee but not on the medial side of the leg or on the upper
p
art of the calfDr Rajiv Ranjan

19. Popliteal fossa
Diamond-shaped space behind the knee
Boundaries :
Superomedially: semimembranosus & semitendinosus
Superolaterally: biceps femoris
Inferomedially: Medial head of gastrocnemius
Inferolaterally: Lateral head of gastrocnemius
Roof : Fascia lata(pierced by the small saphenous vein and the posterior femoral cutaneous NDr Rajiv Ranjan

20. Popliteal fossa
contents
Varying amount of fat
tibiala

popliteal art

popliteal g
lymph nodes lie alongside the popliteal vein.Dr Rajiv Ranjan

21. Popliteal fossa
Floor is formed by :
Popliteal surface of the femur
The capsule of the knee joint reinforced by
the oblique popliteal ligament
& Popliteus muscle covered by its fasciaDr Rajiv Ranjan

22. Common Fibular N
runs laterally do wnwards lying medial to the
biceps tendon
It disappears i
nto the substance of peroneus
longus
To l
fibula(can be rolled)
Branches
Sural communicating N
Lateral cutaneous N of the calf
Superior and inferior genicular N of lateral side
Recurrent genicular NDr Rajiv Ranjan

23. Dr Rajiv Ranjan