Lower limb (and kidney) prosection book Flashcards
How would you orientate gluteal region?
Piriformis muscle: fans out laterally
Which structures are cut during posterior approach to the hip?
-Skin
-Subcutaneous fat
-Fascia lata
-Gluteus maximus
-Short external rotators (piriformis and obturator internus)
-HIp joint capsule
Which nreves are at risk during posterior approach to hip joint?
-Sciatic nerve
-Superior gluteal nerve
Describe blood supply to head and neck of femur
-Main blood supply from extracapsular ring anastamosis-lies around base femoral neck
-Receives supply from medial and lateral circumflex from profunda femoris (medial dominant)
-Also receives some supply from superior and inferior gluteal vessels
-Small arteries ascend from anastamosis to supply head and neck
-Small amount of supply to head from artery to ligamentum teres from obturator, but usually inadequate
What muscles are in the anterior compartment of the thigh?
Hip flexors and knee extensors
-Pectineus
-Iliopsoas
-Tensor fascia lata
-Sartorius
-Quadriceps femoris
What dermatome does lateral cutaneous nerve of thigh supply?
L2 + L3
What are surface markings lateral cutaneous nerve of thigh to perform a block?
1-2cm medial and inferior to ASIS as nerve passes below inguinal ligament
Dermatomes of lower limb
to be continued
myotomes of lower limb
L2 Hip Flexion
L3 Knee Extension
L4 Ankle Dorsiflexion
L5 Big Toe Extension
S1 Ankle Plantarflexion
S2 Knee Flexion
With which anterior abdominal layer is the femoral sheath in continuity?
The femoral sheath is a continuation of the extraperitoneal fascia, formed anteriorly by the transversalis fascia and posteriorly by the iliopsoas fascia
What is the usual order of structures at the hilum in the kidney
VAD: vein, artery, duct
Anterior to posterior:
–> Renal vein
–> Renal artery
–> renal pelvis
How can you identify which side the kidney comes from?
Relationship of renal artery to renal vein in hilum
At what vertebral layer does the kidney lie?
-Paravertebral grooves at T12-L3
-Hilum on left is at transpyloric plane
What are the fascial layers of the kidney?
Deep to superficial:
-Fibrous capsule
-Perinephric fat
-Gerota’s fascia
What are the posterior relations of the kidney?
-Diaphragm (superiorly)
-Quadratus lumborum (inferiorly)
-Psoas major (medially)
-Transversus abdominis (laterally)
What is the lymphatic drainage of the kidney?
-Para-aortic nodes adjacent to renal arteries
-Upper pole may drain superiorly to posterior mediastinal lymph nodes
Describe the internal structure of the kidney
-Dilated upper portion of ureter is called renal pelvis
-Formed by 2 or 3 major calyces, formed by confluence of several minor calyces
-Each calyx has renal papilla draining into it, which is formed by apices of several pyramids of the renal medulla
-The darker renal medulla is surrounded by the lighter coloured cortex
-The renal columns of cortex project inwards between the pyramids
What is the functional unit of the kidney?
-The nephron. Comprises glomerulus and tubule system
How many nephrons are there in a kidney?
Approximately 1 million
How do you orientate knee joint?
Medial/lateral
-Condyle/plateau of tibia is larger on medial side
-Femoral condyle has larger prominence on lateral side of patellar groove to prevent it being dislocated laterally with every contraction of quadriceps –> these muscles have lateral pull
Anterior posterior:
-Femur: patellar groove
-Tibia: intercondylar area more prominent posteriorly
What sort of bone is the patella?
Sesamoid bone: largest in body
What is a sesmoid bone?
-Small bone embedded in muscle or tendon near joint surface
-Functions as pulley to relieve stress on muscle/tendon
What is the function of the patella?
-Attach quadriceps tendon to tibial tuberosity via patellar ligament
-Increase power of quadriceps group by lengthening its leverage
Describe the normal position of the lateral collateral ligament of knee
-Runs from lateral femoral condyle to head of fibula
What is the function of the cruciate ligaments?
-Attach tibia to femur
-Anterior: Prevents tibia being displaced anteriorly (in relation to femur)
-Posterior: prevents tibia being displaced posteriorly (in relation to femur)
What are the attachments of the cruciate ligaments?
Named according to attachment on the tibia
LAMP: lateral acl, medial pcl
-ACL:
–> anterior part of intercondylar area of tibia
–> runs superior and posterior to attach to lateral femoral condyle
PCL
–> Posterior: runs superiorly and anteriorly to attach to medial condyle of femur
Which of the cruciates is the strongest?
POsterior
What is the unhappy triad of knee injuries?
Combination of:
-Rupture of ACL
-Rupture of medial collateral ligament
-Tear of medial meniscus
Often caused by direct lateral blow to knee joint
Where does the saphenous nerve arise?
Saphenous nerve is a branch of the femoral nerve and runs in subsartorial canal with the femoral vessels
What does the saphenous nerve supply?
Medial aspect of calf and foot
What is the relevance of the saphenous nerve to the vascular surgeon?
Can be damaged during varicose vein stripping
What is the clinical significance of hunter’s canal?
Site of anatomical narrowing and therefore common site of turbulent flow and atherosclerotic disease
What attaches to pes anserinus? Where is it located?
‘Say grace before tea’’
Sartorius
Gracillis
semiteninosus
Anteromedial tibia
What is the innervation of the pes anserinus muscles?
SGT FOS
Sartorius: femoral nerve
Gracillis: obturator nerve
Semitendonosus: sciatic nerve
What is the clinical significance of the pes answerinus tendon?
Semitendonosus and gracillis can be harvested for ACL repair
How do you orient tibia?
-Tibial tuberosity anterior
-Medial tibial condyle more prominent
-Medial malleolus more prominent
What are the characteristics of lumbar vertebrae?
-Large kidney shaped body
-Triangular vertebral foramina
-Long, thin transverse processes
-Bulky, square spinous processes
Label parts of lumbar vertebra
Spinous process
Superior articular process
Transverse process
Lamina
Vertebral foramen
Vertebral body
Pedicle (between body and arch)
How would you orientate lumbar vertebra?:
Supero/inferior: spinous process slightly down sloping
What are the articulations between the adjacent vertebrae?
Left and right superior articular facets articulate with the vertebra above
Left and right inferior articular facets articulate with the vertebra below
Vertebral bodies indirectly articulate with each other via the intervertebral discs
What type of joints are the articular facets?
Synovial
Orientated in sagittal plane
Permit limited flexion/extension/lateral flexion but not rotation
What type of pathological process commonly affects articular facet joints?
Osteoarthritis
Which ligaments support the vertebral bodies?
Anterior and posterior longitudinal ligaments
Identify position of ligamentum flavum
Located on posterior boundaries of intervertebral foramina (against facet joints), thereby binding adjacent lamina
What is the composition of an intervertebral disc?
-Intervertebral discs are secondary cartilaginous joints
-Peripheral: fibrous tissue called annulus fibrosus
-Central: Gelatinous matrix called nucleus pulposus
Describe the pathology involved in intervertebral disc prolapse
-Degeneration + subsequent weakening of annulus fibrosis, resulting in nucleus pulposus herniating through a split in the posterior surface of the annulus
-This can cause compression of the spinal cord or spinal nerve roots, culminating in neurological symptoms
What is the common pattern of intervertebral disc herniation?
Most commonly occurs in eccentric manner, as opposed to a central pattern, thereby more often causing compression of spinal nerve roots rather than the spinal cord itself
Which are the most commonly affected nerve roots?
-The most commonly affected nerve root levels are L4/L5, L5/S1
What is the content of the nucleus pulposus?
The nucleus pulposus consists of collagenous fibres (type 2 collagen) in a mucoprotein gel containing polysaccharide
What are the ‘other’ contents of popliteal fossa?
Termination of short saphenous vein
Sural nerve
genicular branches popliteal artery
Where does the popliteal artery bifurcate?
Lower border popliteus
What is a baker’s cyst?
-Synovial cyst extruding from semimembranosus bursa into popliteal space
-Not true cyst as there is usually communication with synovial sac
What are typical characteristics of a thoracic vertebra?
-Heart shaped body
-Small and circular vertebral foramen
-Long transverse processes that angle posteriorly
-Facets on both sides of body for articulation with ribs
-Long spinous processes that angle inferiorly
How many spinal nerves are there?
31
-8 cervical
-12 thoracic
-5 lumbar
-5 sacral
-1 coccygeal
Describe the articulations between the ribs and the thoracic vertebrae
-Each thoracic vertebra articulates with a pair of ribs by means of demifacets on lateral aspects of the bodies (except first T1, and T11/12)
-Each rib articulates with the vertebra at its own level and also with vertebra above, the head of the rib therefby traversing the intervertebral discs
-There are further synovial joints between ribs and transverse processes of vertebrae at their own level
-Ribs at T1, T11 and T12 articulate with their own level only
What landmarks are used when performing a lumbar puncture?
-Line drawn between iliac crests (supracrestal plane) will intersect vertebral column at level of L4
-LP needle should be inserted into space between L4 and L5
What layers will needle pass through when performing lumbar puncture?
Skin
Subcut fat
Deep fascia
Supraspinous ligament
Interspinous ligament
Ligamenum flavum
Dura mata
Arachnoid mater
Describe the course of the common peroneal nerve
-Terminal division of sciatic nerve
-Runs posterior to head of fibula between the lateral head of gastroc and biceps femoris
-Wraps around lateral aspect of neck of fibula underneath peroneus longus, descends beneath this muscle and divides into deep and superficial peroneal branches
What is the clinical significance of the position of the common peroneal nerve?
Its superficial location as it wraps around proximal fibula leaves it susceptible to injury from trauma/surgery/too tight asts
What joints and muscles are involved in inversion and eversion of the foot?
-Occurs at subtalar joint (hinge joint)
-Inversion: tibialis anterior
-Eversion: muscles of lateral compartment (plus peroneus tertius)
