1. Thigh musculature, Knee and ankle osteology
Lower Extremity
Thigh musculature, Knee and ankle osteology

2. Objectives
Describe the gross anatomy for each system (circulatory, muscular, nervous, and skeletal) in the lower extremity.
Integrate the systems to discuss the lower extremity stability and mobility functions.
Analyze common injuries in the lower extremities.
For each muscle, describe how the attachment sites result in an action around a joint.
For each muscle, identify the innervation (peripheral nerve and nerve roots).
Pulled from syllabus

3. There are 4 genicular arteries that supply the hip joint
True
False B

4. Gluteus medius is an internal rotator when the hip is flexed
True
False A

5. R Gluteus Medius L Gluteus Medius R Gluteus Minimus L Gluteus Minimus
Your patient has trendelenburg gait when body weight is shifted to the R Leg. Which muscle is probably weakest?
R Gluteus Medius
L Gluteus Medius
R Gluteus Minimus
L Gluteus Minimus A

6. Soft spots Femoral Triangle Adductor Canal Borders: Problems?
Femoral triangle borders:
lateral – Sartorius
superior – inguinal ligament
medial – adductor longus
floor – iliopsoas laterally, pectineus medially
roof – fascia latae
contains femoral nerve, artery, vein (VAN)
Problems: femoral hernia – more common in women than men -> loop of small intestine pushed into femoral sheath
Adductor canal borders:
anterior – VMO
posterior – adductor longus & magnus
roof – Sartorius
spans from apex of femoral triangle to adductor hiatus
contains femoral artery, femoral vein, saphenous nerve (branch of femoral, ends before hiatus)

8. Adductors Large moment arm for adduction
Small moment arm for internal hip rotation
Obturator nerve
Shaft bends anteriorly – creates a moment arm for adductors around long axis of femur
moment arm gets larger as hip is flexed (pg. 417 Neumann)
Describe all muscles involved in internal rotation:
glut med and min
TFL
adductors
medial hamstrings
Superficial Layer:
Pectineus -> pectineal line of femur
Adductor Longus -> linea aspera
Gracilis -> pes anserine
Middle Layer:
Adductor brevis -> between pectineus and longus
Deep Layer:
Adductor magnus
hamstring part -> adductor tubercle (palpated)
adductor part -> entire length of posterior femur

9. Clinical Relevance Groin injury or “pulled groin”
Gracilis muscle transplant
Groin injury or “pulled groin”
strain, stretching, or tearing of proximal attachment of flexors or adductors
usually in sports that require quick starts or extreme stretching
Gracilis muscle used in grafts
not very effective – can be used to repair forearm muscles or for nonfunctional external anal sphincter to significantly improve quality of life

10. Your patient has damage to the obturator nerve
Your patient has damage to the obturator nerve. Which muscle would be unaffected?
Adductor longus
Adductor brevis
Pectineus
Hamstring portion of adductor magnus
Adductor portion of adductor magnus D

11. Tibial plateau – flat, rotates around femoral condyles
Interosseous membrane – criss cross pattern, strong membrane, attachment site for
posterior tib
extensor hallucis longus
Opening for anterior tibial artery

12. Genu valgus and varus will change amount of force through each condyle
Healthy knee xray features
joint space (menisci don’t show on xray)
equal spaces
Note how unstable the knee joint is

13. To provide stability, ligaments are essential!
MCL – broad, expansive, attached to medial meniscus, medial epicondyle -> medial condyle of tibia
LCL – thick and cord-like, lat epicondyle -> fibular head
ALL – new ligament found in 2013 – lateral femoral epicondyle -> gerdy’s tubercle
deep to IT band, but fibers attach to epicondyle
ACL & PCL next slide

14. https://www.youtube.com/watch?v=RTV5Yo3E7VQ ACL
from anterior intercondylar eminence -> posterior inner part of lateral condyle
PCL
posterior intercondylar eminence -> anterior inner part of medial condyle
Video
Knee menisci
medial meniscus – half moon shape
lateral meniscus – circular
Anchored to tibia anteriorly and posteriorly by horns -> intercondylar eminence
Menisci provide cushion for large amounts of force
triple joint contact area
during walking, forces crossing the knee are typically 2-3 times body weight, maximally reaches up to 9 times body weight
Lateral meniscus is more mobile – typically damaged with ACL
Medial meniscus is anchored by MCL – can be damaged with MCL
Patella tracking – knee biomechanics group!!

15. Bursae & Bursitis Prepatellar Infrapatellar Suprapatellar Pes anserine
Superficial
Deep
Suprapatellar
Pes anserine
MCL
Iliotibial
Locations of bursae
prepatellar – superficial to patella
infrapatellar – superficial and deep to patellar ligament
suprapatellar – deep to quad tendon
pes – deep to pes anserine
MCL – deep to MCL
iliotibial – deep to IT band near insertion
Bursitis
inflammation or irritation of synovial sacs
pain occurs during movement the bursae is supposed to protect (pes bursitis = pain while contracting pes muscles)
furthermore, using those muscles will continue to inflame the bursa
MRIs of prepatellar bursitis

16. What’s wrong with this picture?
Nothing
The ligaments shown are wrong
The patella is out of place
The knee doesn’t bend that way
There is a ligament missing
C, E

17. Knee rotation and the locked position
Full extension & 10 degrees external rotation
All ligaments taught, maximal joint contact

18. Clinical Relevance Genu varum & genu valgum Patellofemoral syndrome
Patellar dislocation
Bursitis & popliteal cysts
Knee replacement
Genu varum leads to medial condyle osteoarthritis
Genu valgum leads to lateral condyle osteoarthritis
gait repeatability is the same in patients with knee osteoarthritis as in normal individuals*
Patellofemoral syndrome
“runner’s knee”
abnormal tracking can cause degenerative trauma
strengthening VMO supposedly helps – seen research that suggests otherwise
hint hint: another potential topic!
Patellar dislocation
more common in women, larger q-angle (quadriceps angle)
femur is shaped to prevent lateral dislocation (lateral condyle extends farther anteriorly than medial, deeper groove laterally
Bursitis & popliteal cysts
prepatellar bursa most commonly aggravated

19. O’Donoghue Triad
MCL, ACL, and lateral meniscus often torn together – “unhappy, terrible triad”, “blown knee”
Still often considered MCL, ACL, medial meniscus but it has been found that lateral meniscus is more often affected and medial meniscus tears are always accompanied by lateral meniscus damage as well.
valgus force to knee
Symptoms:
Pain in affected knee
Stiffness and swelling in affected knee
Catching or locking of the knee in affected knee
Instability of the knee with twisting or side-to-side movements(The sensation of the knee "giving out").
Inability to move the knee through its full range of motion

20. Your patient suffered a lateral blow to the knee with the foot planted while playing soccer. Which of the following is least likely to have suffered damage?
ACL
PCL
MCL
Medial meniscus
Lateral meniscus B

21. While rollerblading, your patient ran into a short wall
While rollerblading, your patient ran into a short wall. Which of the following is most likely damaged?
ACL
PCL
MCL
Medial meniscus
Lateral meniscus B

22. Quadriceps Rectus Femoris Vastus Lateralis Vastus Medialis
Vastus intermedius
¾ quads pull the patella laterally
Innervated by femoral nerve
VL is large, linea aspera -> quad tendon
strong and pulls laterally
VM is smaller with angled muscle fibers, linea aspera -> quad tendon
weaker, often too weak to counteract VL
VI fills space under VL and VM – larger than it looks, anterior & lateral shaft of femur -> quad tendon

23. Clinical Relevance Contusions Avulsion fractures Hematomas
Charley horse
Contusions
“hip pointer injury” – contusion of iliac crest
bleeding from ruptured capillaries into soft tissues (muscles, tendons, connective tissue)
Avulsion fractures
often confused as a contusion
tendon rips off part of the attachment site from the bone
Sartorius or rectus femoris common avulsion fractures in “hip pointer injuy”
Hematomas
blood clot (hema – blood; toma – mass)
contusions large enough to clot
Charley horse
acute cramping of a muscle from ischemia, nocturnal leg cramps, contusion

24. Hamstrings Biceps Femoris Semitendinosus Semimembranosus Long head
Short head (not a hamstring)
Semitendinosus
Semimembranosus
Biceps Femoris
Long head
fused with semitendinosus proximally
ischial tuberosity -> fibular head
distally, splits around the LCL
tibial nerve
Short head (not a hamstring)
fused with long head distally
lateral intermuscular septum, linea aspera -> fibular head
common fibular nerve
Semitendinosus
ischial tuberosity -> pes anserine (medial tibia)
very superficial
distally, half the muscle is strong, cordlike tendon
possibly for energy efficiency?? Possibly to primarily act on the hip??
Semimembranosus
ischial tuberosity -> medial condyle of tibia, partially attaches to medial meniscus
proximally, half the muscle is thin membranous type tendon
possibly for energy efficiency?? Possibly to primarily act on the knee??
Hint hint: potential topic for final essay

25. What is the muscle highlighted on the left?
Biceps femoris long head
Biceps femoris short head
Semitendinosus
Semimembranosus A

26. What is the muscle highlighted on the right?
Biceps femoris long head
Biceps femoris short head
Semitendinosus
Semimembranosus D

27. Popliteal fossa Task: Borders: Identify each of the numbers
Superomedial
Superolateral
Inferomedial
Inferolateral
Floor
Roof
Identify each of the numbers
Pass this in for participation points
Considerations for popliteal fossa – prescribing wheelchairs, sitting for long periods at a time

28. Break

29. Ankle joint Hinge joint with 3 articular surfaces:
Medial surface of fibula -> talus
Inferior tibia -> trochlea of talus
Lateral surface of medial malleolus -> talus

30. Ligaments – ankle joint
Deltoid ligament
4 parts
Fibular collateral ligaments 3
Tibiofibular ligaments
Deltoid – strong, fibrous, resists eversion; bony structure helps as well
anterior tibiotalar
tibionavicular
tibiocalcaneal
posterior tibiotalar
Fibular – very strong, resists inversion; high mobility; often stretched, torn, or breaks fibula (like our cadaver!)
anterior talofibular
calcaneofibular
posterior talofibular
Anterior and posterior talofibular – resist separation of the ankle joint

31. Clinical relevance Eversion and inversion sprains and fractures
Deltoid ligament and fibular collateral ligaments are so strong, they will often break bones before tearing