Clinical Anatomy of the Lower Limb

Question 1

Gross structure of the bony pelvis?

Answer 1

Ilium, ischium, pubic bone and sacrum

These are held by strong ligaments:
• Sacrotuberous
• Sacrospinous
• Sacroiliac

Question 2

Clinical significance of the pelvic vasculature?

Answer 2

Many arteries and veins, meaning that there is potential for bleeding to occur, with a pelvic fracture; there is also a large potential space that can be filled before clotting occurs

Question 3

Pelvic nerves?

Answer 3

Pudendal nerves and pelvic splanchnic nerve are important for bladder and bowel control; with pelvic fractures, a PR exam must be done

Sciatic nerve supplies the lower limb and every muscle below the knee; it is sensitive to injury in the greater sciatic notch

Question 4

Contents of the pelvis?

Answer 4

Urethra, rectum and bladder can be injured with pelvic trauma

Question 5

Describe the capsule of the hip joint

Answer 5

Inserts into the ring anastamosis at the base of the neck

Question 6

Clinical importance of the blood supply of the hip joint?

Answer 6

Retinacular arteries are susceptible to damage in intracapsular hip fractures

Superior head is supplied by small end arteries and these are susceptible to blockage with, e.g: fat, thrombus, N gas (decompression sickness); can lead to AVASCULAR NECROSIS OF THE FEMORAL HEAD

Question 7

Main abductors of the hip? Clinical importance?

Answer 7

Gluteus medius (mainly) and minimus; these tilt the pelvis (towards the stance leg) when standing on one leg (single stance phase of gait)

Damage can cause +ve Trendellenburg gait (pelvis tilts away from stance leg)

Question 8

Function of the gluteus maximus?

Answer 8

Extension and external rotation

Question 9

Categories of hip joint muscles?

Answer 9

Flexors, adductors and short external rotators

Also, rectus femoris and hamstrings act as secondary flexors/extensors

Question 10

Injuries of the anterior muscles of the thigh?

Answer 10

Quadriceps femoris can have:
• Muscle tears
• Quadriceps OR patellar tendon rupture (must test SLR)

Question 11

Nerve supply to the quadriceps femoris?

Answer 11

Femoral nerve

Question 12

Injuries of the posterior muscles of the thigh?

Answer 12

Hamstrings can have:
• Muscle tears
• Common hamstring origin avulsion (more serious)

Question 13

Why can the semitendinosus be used as a tendon graft for, e.g: ACL reconstruction?

Answer 13

Semimembranosus and biceps femoris are the most powerful hamstrings

Question 14

Nerve supply to hamstrings?

Answer 14

Sciatic nerve (tibial and common fibular nerves)

Question 15

Clinical importance of the nerve supply to the adductors of the thigh?

Answer 15

Supplied by the OBTURATOR nerve, which can refer pain from the hip to the knee (must do hip exam in someone with knee pain and must check internal rotation)

Question 16

Function of the adductor hiatus?

Answer 16

Transmits:
• Femoral artery and vein from Hunter’s (subsartorial) canal into the popliteal fossa
• Saphenous nerve (supplied sensation to the medial calf and shin)

Question 17

Types of cartilage in the knee?

Answer 17

Hyaline cartilage (covers bones)

Fibrocartilaginous menisci (act as shock absorbers between the convex femoral condyles and relatively flat plateau)

Question 18

Describe meniscal tears

Answer 18

Medial meniscus is fixed whereas the lateral meniscus is mobile

MM tears are more common (9:1)

Question 19

Ligaments of the knee and their functions?

Answer 19

MCL - resists valgus stress

ACL - resists internal rotation and anterior translation of the tibia

PCL - resists posterior translation of the tibia OR anterior translation of the tibia, e.g: descending stairs

LCL - resists valgus stress and helps to resists external rotation (with PCL and posterolateral corner)

Question 20

Anatomical and mechanical axes of the lower limb?

Answer 20

Average tibiofemoral angle (anatomic axis) is 6 degrees which causes the centres of the hip, knee and ankle (mechanical axis) to align perfectly

This allows symmetric distribution of loaf between the medial and lateral compartments

Question 21

Consequences of varum/valgum deformity of the knees?

Answer 21

Increased load on the knee predisposes to medial or lateral, respectively, compartment OA

Question 22

Function of the knee bursae?

Answer 22

Reduce friction but may become inflamed (bursitis), part. in people who kneel a lot, e.g: carpenters:
• Suprapatellar and infrapatellar
• Prepatellar
• Patellar, sartorius, gracilis, semitendinosus tendons
• Pes anserine
• Shin bone

Question 23

Compartments of the leg and the nerve supply?

Answer 23

Anterior - deep peroneal/fibular nerve

Lateral - superficial peroneal/fibular nerve

Superficial and deep posterior - tibial nerve

Question 24

Describe compartment syndrome

Answer 24

Swelling results in pressure, which occludes venous drainage and leads to secondary ischaemia

Emergency fasciotomy to relieve pressure

Question 25

Injuries of the ankle?

Answer 25

Ligament sprains are common and usually stable; for instability, 2 out of 3 lateral ligaments must be incompetent

Sometimes, the ankle joint can become unstable with a mixture of fracture and ligament rupture

Question 26

What to look for on X-ray, for instability?

Answer 26

Talar shift

Question 27

What is tarsal coalition?

Answer 27

Abnormal connection between the tarsal bones

Question 28

Movements of the foot?

Answer 28

Composite movements inv. the ankle and subtalar joints and the midfoot, allowing pronation and supination

Eversion/inversion

Dorsiflexion/plantarflexion

Abduction/adduction

Question 29

What individual movements does pronation of the foot consist of?

Answer 29

• Eversion
• Abduction
• Dorsiflexion

Question 30

What individual movements does supination of the foot consist of?

Answer 30

• Inversion
• Adduction
• Plantar flexion

Question 31

Maintenance of the medical arch of the foot?

Answer 31

Tibialis posterior and plantar fascia but the tibialis posterior tendon and plantar fascia can degenerate (microtears, tendonitis and pain)

Also, the tibialis posterior can elongate leading to painful flat foot (pes planus) and hindfoot valgus

Question 32

Describe creation of claw and hammer toe deformities

Answer 32

Imbalance of the flexor and extensor tendons