MSK 6 - Lower Limbs 2 Flashcards
What is the pelvic girdle?
The pelvic girdle is a bony ring consisting of the sacrum and right and left hip bones, joined anteriorly at the pubic symphysis and posteriorly by the sacroiliac joints.
What makes up the pelvic girdle?
- Left and right hip bones
- Joint anteriorly by pubic symphysis
- Joined posteriorly by sacroiliac joints
What is A?
Greater sciatic foramen
What is B?
Sacrotuberous ligament
What is C?
Sacrospinous ligament
What is D?
Lesser sciatic foramen
Which sciatic foramen is the route for structures entering or leaving the pelvis?
Greater sciatic foramen
Which sciatic foramen is a route for structures entering or leaving the perineum?
Lesser sciatic foramen
How can the posterior muscles of gluteal region be organised?
Superficial and deep layer:
- deep layer performs external rotation and provide stability
What is 1?
Gluteus maximus
What is 2?
Gluteus medius
What is 3?
Gluteus minimuis
What is 4?
Tensor fascia lata
What are the gluteal muscles?
- Gluteus maximus
- Gluteus medius
- Gluteus minimus
- Tensor fascia lata
What is the innervation of:
- gluteus maximus
- gluteus medius
- glutius minimus
- tensor fascia lata
- Gluteus maximus
- Inferior gluteal nerve (L5 - S2)
- Gluteus medius
- Superior gluteal nerve (L4-S1)
- Gluteus minimus
- Superior gluteal nerve (L4-S1)
- Tensor fascia lata
- Superior gluteal nerve (L4-S1)
What are the nerve roots of the superior gluteal nerve?
L4-S1
What are the nerve roots of the inferior gluteal nerve?
L5-S2
What are the actions of gluteus maximus muscle?
Extends hip joint and assists in lateral rotation
What is the action of gluteus medius, gluteus minimus and tensor fasciae latae?
They are abductors and medial rotators of hip joint.
What is the deep fascia of the thigh called?
Fascia lata
What does the fascia lata thicken laterally to form?
Iliotibial tract
What 2 muscles attach to the iliotibial tract?
- Tensor fascia lata
- Gluteus maximus
What is the function of the iliotibial tract?
Provides stabilisation to lateral aspect of knee joint
What muscle does the sacral plexus lie on?
Piriformis muscle
Sacral plexus is formed by what nerve roots?
Union of ventral rami of spinal nerves L4, L5 and S1 to S4
What does the sacral plexus supply?
Posterior aspect of lower limb plus perineum
What are the 2 main branches of sacral plexus?
- To lower limb
- Sciatic nerve
- To perineum
- Pudendal nerve
Other than the sciatic and pudendal nerves, what are other branches of sacral plexus?
Superior and inferior gluteal nerves
What muscles are innervated by the superior gluteal nerve?
- Gluteus medius
- Gluteus minimus
- Tensor fasciae latae
What muscle(s) are innervated by inferior gluteal nerve?
Only the gluteus maximus in the gluteal region
Other than sciatic, pudendal, superior/inferior gluteal nerves, what are some others from the sacral plexus that only superficial knowledge of is required?
- Nerve to piriformis
- Posterior cutaneous nerve to thigh
- Nerve to quadratus femoris
- Nerve to obturator internus
What is the largest nerve in the body?
Sciatic nerve
What are the root values of the sciatic nerve?
L4 to S3
Does the sciatic nerve innervate any of the gluteal region?
Within the gluteal region the sciatic nerve contributes very little motor or sensory innervation, aside from branches to the posterior aspect of the hip joint.
What foramen does the sciatic nerve travel through?
Greater sciatic foramen
Describe the course of the sciatic nerve?
It passes through the greater sciatic foramen, inferior to the piriformis muscle, passing behind the deep abductors of the hip joint between the ischial tuberosity and greater trochanter of the femur to enter the posterior compartment of the thigh.
What does the sciatic nerve divide into?
- Tibial nerve
- Common fibular nerve
Where does the sciatic nerve divide into the tibial and common fibular nerves?
Distally from the popliteal fossa
What muscle is highlighted green?
Piriformis
What causes sciatica?
Narrowing of the vertebral foramen which compressed nerve roots
Usually L5 vertebrae
Happens due to ageing decreasing flexibility of muscles, ligaments and joints
What are the 3 muscles of the posterior region of thigh grouped together as?
Hamstrings
What are the 3 muscles that forms the hamstrings?
- Semimembranosus
- Semitendonosus
- Biceps femoris
What is 1?
Seminomembranosus
What is 2?
Semitendonosus
What is 3?
Biceps femoris
What is the action of the hamstrings on hip and knee joint?
- Hip
- Extension
- Knee
- Flexion
What nerve innervates the posterior compartment of thigh?
Sciatic nerve
What artery supplies blood to posterior muscle compartment of thigh?
Profunda femoris (branch of femoral artery)
What is the profunda femoris a branch of?
Femoral artery
What kind of joint is the knee joint?
Synovial hinge joint
What movements are capable at the knee joint?
- Flexion
- Extension
- Small amount of active and passive axial rotation
What is 1?
Patella
What is 2?
Fibula
What is 3?
Tibia
What is 4?
Femur
What is a?
Medial femoral condyle
What is b?
Lateral femoral condyle
What is c?
Lateral tibial condyle
What is d?
Medial tibial condyle
What is e?
Tibial tuberosity
What does the stability of the knee depend on?
The stability of the knee joints depends on the strength and action of surrounding muscles and their tendons and ligaments connecting the femur and tibia.
Which is the most important muscle which helps to stabilize the knee joint?
Quadriceps
What are the ligaments of the knee formed from?
Thickening of joint capsule
What is 1?
Lateral collateral ligament
What is 2?
Medial collateral ligament
What is 3?
Anterior cruciate ligament
What is 4?
Posterior cruciate ligament
What are the ligaments of the knee?
- Lateral collateral ligament
- Medial collateral ligament
- Anterior cruciate ligament
- Posterior cruciate ligament
What are the collateral ligaments also called?
Fibular ligaments
What do the following extend from and to:
- lateral collateral ligament
- medial collateral ligament
- Lateral collateral ligament
- Lateral epicondyle of the femur to lateral surface of head of fibula
- Medial collateral ligament
- Medial epicondyle of femur to medial epicondyle of tibia
What tendon passes deap to the lateral collateral ligament, seperating it from the lateral meniscus?
Tendon of popliteus muscle
What is the medial collateral ligament attached to at its midpoint?
Medial meniscus of knee
Tear both together
What shape do the cruciate ligaments form?
The cruciate ligaments cross each obliquely in the knee to form an ‘X’ shape
N.B. Cruciate means cross-shaped in Latin
Which of the anterior and posterior cruciate ligaments prevents the femur sliding x on the tibia:
- anterior
- posterior
- Anterior cruciate ligament prevents femur from sliding posterior on tibia
- Posterior cruciate ligament prevents femur from sliding anterior on tibia
Why can anterior cruciate ligament injury be so devatating to sportsmen?
Poor blood supply after repair means takes a long time to heal
So important for stability of knee
Is an anterior or posterior cruciate ligament injury more common?
- Anterior more common
- Due to force required by direct blow on tibia to cause injury, comapred to twisting deceleration motions required to disrupt the ACL
Why is the popliteal muscle important?
The popliteus muscle is a small but, nevertheless important muscle in helping release the fully extended or “locked” knee.
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What is the function of the popliteus muscle?
When flexing from a fully extended position, the muscle rotates the femur laterally on the tibia (or vice-versa), allowing for the unimpeded movement of the joint
What are the menisci of the knee?
The menisci are crescent shaped plates of fibrocartilage directly on the articular surface of tibia.
What is 1?
Medial meniscus
What is 2?
Lateral meniscus
What is 3?
Anterior cruciate ligament
What is 4?
Posterior cruciate ligament
What are the main functions of the menisci?
Stability by deepening the socket
Which meniscus firmly adheres to the deep surface of the tibial or medial collateral ligament?
The medial meniscus
What normally causes meniscal tears?
Because of the shape of the menisci, any lateral impact to the knee joint risks both damaging the medial meniscus and disrupting both the ACL and medial collateral ligaments.
What is the largest sesamoid bone in the body?
Patella
What does the patella act as an anchor point for?
- Quadratus femorus tendon superiorly
- Patellar ligament inferiorly
Which movement of the knee causes the patella to move?
Flexion causes it to move inferiorly
What is found around the knee that acts as shock absorbers?
Bursa
What is 1?
Subcutaneous prepatellar bursa
What is 2?
Deep infrapatellar bursa
What is 3?
Subcutaneous infrapatellar bursa
Which bursa communicates with the articular cavity of the knee joint?
Suprapatellar patella
What is the clinical significant os the suprapatellar bursa communicating with the articular cavity of knee joint?
Bursitis of suprapatellar bursa consequently may result in infection entering the knee joint
What is housemaid’s knee (pre-patellar bursitis)?
Friction bursitis caused by friction between the skin and the patella
What muscles are involved in knee flexion?
- Hamstrings
- Semitendinosus
- Seminomembranosus
- Biceps femoris
- Gracilis
- Sartorius
What muscles are involved in extension of the knee?
- Quadriceps femoris
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius