Week 4 Flashcards
What four bones are make up the pelvic girdle?
Ilium
Pubis
Ischium
Sacrum
What are the two main ligaments of the pelvis? What structures do they form?
Sacrotuberous and Sacrospinous ligaments
Form the greater and lesser sciatic foramina
What are the important nerves to be aware of that pass through the pelvis? What do they regulate?
Pudendal and Splanchinc nerves - important for control of bladder and bowel
Also the sciatic nerve, which splits into the tibial and common fibular nerves
Describe the blood supply to the hip. How are these affected in a hip fracture?
What condition could result if some of these smaller end arteries become blocked? Amongst others, what medication in particular could precipitate this condition?
From the deep femoral artery arise the medial and lateral circumflex arteries. These form a ring anastomosis around the head and neck of the femur.
Branching off of these circumflex arteries are the retinacular arteries, which are susceptible to damage if the hip is fractured.
The hip is also supplied by the artery of ligamentum teres (which also passes through the ligamentum teres)
Blockage of/damage to the end arteries e.g. through thrombosis, fat embolis etc. can result in avascular necrosis of the head of the femur. Long term steroid use affects fat metabolism and could result in AVN.
Of the gluteal muscles, which is the main abductor?
What test can be performed to assess abductor function?
Gluteus medius, helped by gluteus minimus
Trendelenburg’s Test can be used to detect abductor weakness - when standing on one leg, patient will lean away from leg remaining on the ground.
Which of the hip muscles is the most powerful flexor of the hip?
The iliopsoas, made up of the psoas major and the iliacus
Which nerve supplies the quadriceps (and the rest of the anterior compartment of the thigh)?
What test can be used to assess the function of this nerve?
The femoral nerve
The straigh leg raise can be used to assess this nerve’s function
Which nerve supplies the posterior compartment of the thigh? What is the one exception?
Where can tendons for ACL reconstruction be harvested from?
The tibial division of the sciatic nerve (L5, S1, S2) supplies the posterior compartment of the thigh, except the short head of biceps femoris, which is supplied by the common fibular nerve
Tendons can be harvested from semitendonosus (preferred), and also the patellar tendon (there is more morbidity associated with harvesting from here)
What nerve supplies the adductors of the hip? Pathology of this nerve can lead to referred pain, where?
What range of motion is first lost in hip pathology?
The obturator nerve (L2, L3, L4) supplies the adductors of the hip, except the hamstrings part of Adductor magnus, which is supplied by the Tibial nerve
Pain from the hip can be referred by the obturator nerve to the knee - classic case is slipped upper femoral epiphysis (SUFE), presenting as knee pain in teenagers.
First ROM to be lost in hip pathology is internal rotation
What structures pass through Hunter’s (subsartorial) Canal on their way from the adductor hiatus to the popliteal fossa?
The femoral artery and femoral vein.
Also the saphenous nerve.
What are the two types of cartilage present in the knee joint?
What is the difference between the Medial and Lateral meniscus?
Hyaline cartilage
Fibrocartilaginous menisci
The medial meniscus (MM) is fixed, while the lateral meniscus (LM) is mobile. MM is much more prone to tears (9:1)
The knee contains 4 separate ligaments - what forces do each of them resist?
Medial Collateral Ligament (MCL) resist valgus stress (knock-knees)
Lateral Collateral Ligament (LCL) resists varus stress (bow-legs) and helps to resist external rotation
Posterior Cruciate Ligament (PCL) resists anterior and posterior translation of the tibia
Anterior Cruciate Ligament (ACL) resists internal rotation and anterior translation of the tibia
Genu varum = knock-knees/bow-legs
Bow legs
Genu valgum = knock-knees/bow-legs
Knock-knees
What are the 4 bursae present on the anterior surface of the knee joint?
What condition can result in people who kneel a lot?
- Suprapatellar
- Prepatellar
- Infrapatellar
- Pes anserine
Bursitis (inflammation of the bursa) is common in people who kneel a lot e.g. Housemaid’s Knee
What nerve supplies…
The anterior compartment of the leg?
The posterior compartment of the leg?
The lateral compartment of the leg?
Anterior = deep fibular nerve
Posterior = tibial nerve
Lateral = superficial fibular nerve
What bones make up…
The hindfoot?
The midfoot?
The forefoot?
Hindfoot = calcaneus and talus
Midfoot = navicular, medial, intermediate and lateral cuniforms, and the cuboid
Forefoot = metatarsals and phalanges
What are the components of hyaline cartilage?
Water
Proteoglycans
Chondrocytes
Collagen
What do chondrocytes produce to regulate the ECM?
Collagen
Prostaglandins
Enzymes
What is the only area of hyaline cartilage that receives a blood supply?
The calcified layer, beyond the tidemark
What can lead to defects in articular cartilage?
Briefly describe the healing process of cartilage
Trauma
Atraumatic causes
- osteochondritis dessicans (temporary loss of blood supply to hyaline cartilage, leading to ischaemia and fragmentation
- osteoarthritis
- inflammatory arthritis
Only full thickness injuries heal, i.e. those that pass the tidemark. Hyaline cartilage is replaced with fibrocartilage - has less friction and more prone to wear and tear