Flashcards in Clinical Relevance Deck (89):
Patient presents with numbness over lateral forearm and hand, which nerve root is most likely damaged?
Patient sustained a fracture to mid-shaft of humerus, which nerve is in danger of damage?
A patient has sustained a fracture to the tibia and put in a cast that is split to avoid compression of which nerve?
Common peroneal (fibulae)
The appeal/calf muscle pump aids venous return of blood to heart, which vein does it directly act upon?
This artery normally bifurcated just proximal to the cubical fossa
What are the three joints in the ankle and foot?
Ankle joint (talocrural joint) -tibia and talus
Subtalar joint - talus and calcenous
Midtarsal joint - talus, calcaneous and navicular, cuboid
This artery branches from circumflex arteries and supplies head of femur by traveling in the capsule of hip joint in adults
This artery gives rise to dorsalis pedis on dorsum of foot
Anterior tibial artery
This artery passes in the sole of the foot where it gives two branches
Posterior tibial artery
The knee must be flexed to slacken the fascia in order to asses the pulse of this artery
Which muscles can be damaged when flexing the hip with an extended knee?
They pass both hip and knee joint
If the slack is taken up by one of the joints the other is limited
Which muscle correct the pull of quadriceps to ensure normal patella tracking?
Which muscles pull the lateral meniscus posteriorly when unlocking the knee from a locked position?
Which muscles are affected is superior gluteal nerve is damaged?
How does it present?
Gluteus mediums and minimums
Positive Trendelenburg gait
Which muscle will addiction the hip and flex the knee?
What is main blood supply of head of femur in children?
Branch of obturator artery
How does scapula move during shoulder abduction?
Rotates laterally to prevent acronym process from knocking onto greater tubercle of humerus
Why is dislocation of radial head more common in children than in adults?
Radial head is not fully developed, so it slips out of annular ligament
What are main action of muscles in the anterior compartment of leg?
Extension (dorsiflexion) of ankle
What are main differences between hip and shoulder joint?
Hip is adapted for stability, shoulder is adapted for movement
Glenoid fossa is much smaller than acetabulum
Hip capsule is surrounded by spiral ligaments that limit movement
Rotator cuff in shoulder is lax inferiorly to accommodate the head of humerus during full abduction of shoulder joint
Difference between smith and coleus fracture
Both are fracture of radius
Colles - dorsal angulation of distal bone fragment, outstretched hand
Smith’s - Palmer angulation of distal born fragment, flexed wrist, more dangerous due to neurovascular structures in this direction
Which carpal bone is particularly at risk of fractures and why?
Scaphoid, due to narrowing/neck
Hard to detect on x-rays
Can lead to a vascular necrosis of proximal fragment (blood supply from radial artery distal to proximal)
Presents as tenderness over anatomical snuff box
Which muscles of forearm bring about adduction of wrist?
Flexor and extensor carpi ulnaris
Which muscles in anterior compartment of forearm cause clawing of the medial two digits if the lunar nerve is damaged at level of elbow?
Flexor digitorum superficialis
Which powerful muscle would you use to unscrew lid from a jar?
Which muscle can bring about both pronation and supination?
Which muscle form the boundary of anatomical snuffbox?
Ulnar border is extensor pollicis longus
Radial border is extensor pollicis bee is and abductor pollicis longus
What causes the patella to be pulled laterally and therefore not track normally?
Angle of femur from pelvis to knee is oblique whereas line of pull of quadriceps muscle is straight. In knee extension 2 forces occur, one that extends and one that pulls patella laterally.
What 2 factors help to ensure normal tracking of the patella?
Raised lateral femoral condyle and horisontal fibers of vastus medialis pull the patella medially during knee extension
What anatomical features cause women to be more prone to anterior knee pain than men?
Wider pelvis in women makes the angle of femur more oblique
What is anterior knee pain?
Patella is not tracking normally, hits against lateral epicondyle which causes pain
Describe femoral triangle
Area that contains femoral vein, artery and nerve (VAN from medial to lateral)
What is compartment syndrome and how is it managed?
Often occurs due to trauma
The pressure increases within the compartment exceeds the pressure within the capillaries meaning they cannot fill and supply blood to structures within that compartment. Can lead to avascular necrosis.
Patient returns to fracture clinic with weakness in dorsiflexion (“foot drop”). What is likely to have caused this?
Crush injury to common peroneal/fibular nerve
When is gluteus Maximus used in walking?
If a patient has weakness affecting gluteus Maximus, which activities will this be noticeable in?
Getting out of and sitting down in a chair
What function does gluteus Maximus have at the knee via the Iliotibial tract?
What is the most powerful/main elbow flexor?
What is main action of gluteus medius and minimus at hip of a non-weightbearing (free) lower limb?
What is main action of gluteus medius and minimus at hip of a weightbearing (fixed) lower limb?
Pulling pelvis and trunk over the stance leg, this pulling centre of gravity over weightbearing limb
Damage to what nerve causes loss of function to gluteus medius and minimus?
Superior gluteal nerve
What are the types of abnormal gait?
Antalgic gait - short weight-bearing stance on painful limb
Short-leg gait - shoulder dip, caused by LLD
Trendelenburg gait - waddling, loss of abductor function
High stepping gait - flexed knee and high lift of foot to avoid foot dragging, nerve palsy (peroneal or sciatic)
Stiff knee - knee cleared of floor by swinging out away from body, fusion of knee
Pete is given a boot to wear that prevents him from using gastrocnemius and soleus while the tendon heals. The boot has a wedge that fixes the ankle in a plantarflexed position. Why is this important?
Avoids stretching of muscle which allows tendon to heal
Damage to medial humeral epicondyle can compromise which nerve?
Which bony landmarks are used to find the femoral pulse at the mid-inguinal point?
ASIS and pubic symphysis
Which two arteries are assessed at the medial malleolus and the dorsum if the foot?
Medial malleolus - posterior tibial
Dorsum - dorsalis pedis, continuation of anterior tibial
If blockage occurs in the external iliac artery,how could blood bypass this obstruction?
Internal iliac artery - gluteal artery - perforating branches - profundus femoris - femoral
If blockage occurs in popliteal artery , how could blood bypass this obstruction?
Pro funds femoris joins the genicular anastomoses
Why is the arterial supply initially from the obturator artery instead of retinacular vessels?
Retinacular vessels will get damaged if they cross growth plate before it is fused
What are the three extracapsular ligaments in the hip joint?
Why is it easier to flex the hip rather than extend?
Iliofemoral, ischiofemoral, pubofemoral
These ligaments spiral around the hip joint.
Flexion unspirals these ligaments allowing them to become loose
Extension spirals these ligaments more tightly, making them taught and immovable
This mechanism is useful when standing as it preserves energy (do no need to use muscles)
Why do we replace the entire head rather than pin the fracture in intracapsular hip fractures?
Avascular necrosis of head of femur due to retinacular vessels
What is function of ACL and PCL?
ACL - prevents anterior displacement of tibia on femur
PCL - prevents posterior displacement of tibia on femur
A rugby player is tackled by a slam to the lateral aspect of his left knee. The rugby player is unable to get up an is in considerable pain. Which collateral ligament is most likely damaged?
Medial, due to over stretching
Fibers of medial collateral ligament and medial meniscus are blended together, which means that damaging the medial collateral ligament could result in a meniscal tear
What is the general structure and function of a bursa?
A closed space between two fascism planes where a small amount of synovial fluid adds lubrication to allow one fascial surface to move smoothly over the other, reducing friction between the structures
It is a common myth that a bursa is a fluid filled sac, it’s is not. When does a bursa become fluid filled?
Bursitis, inflammation of bursa
Synovium produces excessive synovial fluid to bathe/cushion the area
Commonest types of bursitis
Subacromial/subdeltoid (painful arc)
Courtney is wearing 7-inch heels for a night out. She falls and twist her ankle. A doctor ascertains that her lateral collateral ligaments have been sprained following the flexion-inversion injury. Why are these types of injuries more likely when the foot is in the fenced position?
Why is the foot more likely to invert and damage the lateral ligaments than inverts and damage the medial ligaments?
The talus bone is narrower towards the posterior aspect. When the ankle is flexed a much narrower surface of talus articulates with the tibial/fibular complex, this creating space in the ankle joint which makes the ankle joint more unstable
Deltoid ligament (medial) is much stronger than ATFL and CFL
What creates and supports the transverse and longitudinal arches of foot?
Transverse arch - created by wedge shape of cuneiform bones (narrow inferiorly), supported by fibularis longus tendon
Longitudinal arch - creates by calcaneus, navicular, talus, cuneiforms and metatarsal 1-3
Supported by long plantar ligament
Tom has fallen arches or flat feet (pes planus), what does this mean anatomically?
The support for maintenance of the longitudinal arches of the feet has been compromised.
The arches are supported and maintained by muscles and ligaments. Ligaments and the plantar aponeurosis provide passive mechanism of support. Muscles provide dynamic support by contracting as weight is loaded into foot, allowing this weight to be gently loaded onto joints and ligaments
Why is cephalon vein useful for doctors?
Distal end - emergency fluids
Cubical fossa - drip vein
Deltoid - syringe driver
Where is venous blood sampling usually obtained from and what is important to be aware of?
Median cubical vein
Brachial artery should be protected under bicipital apeoneurosos, however there are some variations where brachial artery bifurcated higher up causing radial+ulnar artery to travel more superficially, which increases risk of puncturing artery. If in doubt, stick to cephalic.
Which muscle is predominantly responsible for preventing winging of scapula by holding medial border of scapula against chest wall?
What are the other actions of this muscle?
Serratus anterior innervated by long thoracic nerve
Scapular protraction and lateral rotation
Patient has been involved in bike accident, landing on left shoulder, bending head sharply to right. Registrar notes that she has diminished sensation over top of her shoulder and lateral arm. Which nerve root would you suspect affected? Which movements are most likely affected? How can you confirm that this is a root injury rather than a peripheral nerve injury?
Axillary nerve damage results in loss of sensation in regimental badge area, not whole of C5
If both dermatome and matching myotome is damaged it is most likely a nerve root injury
After a lumpectomy Margaret’s neck seems a bit lopsided and she experiences weakness of her shoulder, espc when reaching for higher shelves. Which muscle has been affected? Why has this muscle become wasted? What examination findings to we expect?
Spinal accessory nerve has been damaged during surgery
Impaired elevation of scapula and abduction >90•
What is the function of flexor retinaculum?
Prevents bowstringing of flexor tendons, thus increasing effectiveness
James has sustained a deep laceration to the medial aspect of his forearm just proximal to the medial epicondyle. On exam, James appear to have diminished sensation over medial aspect of his hand and his medial digits claw when asked to wiggle fingers. Which muscles are innervated by ulnar nerve in the forearm? What happens with flexion of wrist? What happens with extension and abduction of wrist? What happens with adduction of wrist?
Flexor carpi ulnaris and medial 1/2 of flexor digitorum profundus
The wrist will deviate to radial side due to unopposed action of flexor carpi radialis
Should extend and abduct as normal
Extension of wrist towards ulnar side, due to unopposed action of extensor carpi ulnaris
Joanna has noticed pain and tingling on radial side of hand and weakness holding a pen. Pain is and at night and causes her to wake. GP suspects carpal tunnel. What causes median nerve compression? Which muscles does median nerve supply in the forearm and hand?
Why is sensation speed in centre if palm? Why is there no pain proximal to wrist joint? What are management?
Either decreased size of carpal tunnel (trauma, ganglion) or increased size of contents in carpal tunnel (tendinitis).
Anterior forearm - all muscles except flexor carpi ulnaris and medial 1/2 of flexor digitorum profundus
Hand - LOAF muscles
Innervation of this area arises from a branch of the median nerve that passes over carpal tunnel
Median nerve only provides sensory innervation to hand
Splint, steroid injection, release surgery
How to asses flexor digitorum profundus only?
Hold PIP joint, because flexor didigoroum superficialis only crosses PIP and flexor digitorum profundus crosses DIP
A registrar tests the function of flexor digitorum superficialis in an injured digit by holding down the distal phalanges of uni juries disgust. Why does this work?
A single tendon from flexor digitorum profundus cannot work independently of other digits
What is the normal digital sweep? What group of muscles ensure that we have this?
Fingers flex in sequence starting proximally (MCP) and finishing dismally (DIP). Ensures that we can grip objects.
When the long flexors of fingers contract their initial action is at the most distal joint, and we lose our normal digital sweep. The lumbricals preserve our NDS. They attach proximally to the tendons of long flexors and dismally to the extensor expansion, thus assisting flexion of MCP and extension of PIP and DIP
If ulnar nerve is damaged proximally the clawing of fingers is less extreme than damage affecting nerve distally
Gerald has sustained a mid-shaft humeral fracture and you suspect radial nerve damage. Radial nerve also supplies triceps, given location of fracture would you expect Gerald to extend his elbow?
Yes as it is innervated before site of fracture
Why is scaphoid bone at most risk of fracture when falling on outstretched hand?
The radius articulates with the carpus bones. Force of fall is transmitted laterally/radially through the campus bones to radius, affecting scaphoid
What are the boundaries of the anatomical snuffbox?
Medial: extensor pollicis longus
Lateral: extensor pollicis brevis and abductor pollicis longus
What is the cause of boutonnière deformity?
The median band (central slip) of dorsal expansion is damaged, allowing PIP joints to push between lateral bands.
Why is it important to preform Allen’s test before obtaining an arterial blood gas sample?
An ABG is taken from radial artery. To establish the presence of a parent anastomoses between the deep and superficial palmar arches. If radial artery is compromised during ABG and there is no patent anastomoses, structures supplied by the deep palmar arch will become ischemic.
A cyclist dislocated shoulder. How would you asses if the axillary nerve is compromised?
Sensation over regimental badge area
Why can shoulder dislocations lead to axillary nerve damage?
Humeral head is initially forced inferiorly (due to lack of rotator cuff muscles, lax capsule) before being pulled anterior of posteriorly. Axillary nerve passes inferior to the shoulder joint.
After a dislocation patients have to undergo physio to rebuild strength in rotator cuff (prevent recurrence). What actions will increase strength of these muscles?
Lateral and medial rotation, abduction
A mother quickly grabs her 5y old daughters hand and pulls her back to stop her from falling. The daughters arm is hurt in the process. What has happened? What can prevent this from happening in a child that is lifted by their arms?
Dislocation of head of radius.
Head of radius is small in children and can therefore easily slip through annual ligament.
Contract/tense their muscles in anticipation of swing, which keeps the head of radius in place.
Lindy has sustained a severe laceration in antecubital fossa. When asked to make a fist - sign of benediction. No sensation in lateral 3 and 1/2 digits and no power in LOAF muscles flexor digitorum superficialis and radial flexor digitorum profundus. What nerve has been divided? Why does it look like sign of benediction?
FDS and radial part of FDP are paralyzed
Patient, that works as a cleaner, present with clawing of two medial fingers at rest, wasting of interosseii and hypothenar eminence. What has happened?
Why are the fingers clawed?
Hammer hamate syndrome
Deep motor branch of ulnar nerve is being compressed against hook of hamate
Wasting of interosseii and lumbricals lead to clawing as a result of unopposed action of FDS and FDP
Explain cubical tunnel syndrome. How does it present?
Ulnar nerve is being compressed as it goes around medial epicondyle
Presents as mild passive ulnar clawing, because FDP is paralyzed so no flexion of DIP. Only FDS is acting unopposed, flexion of PIP less clawing.
All intrinsic muscles of hand (except LOAF) and flexor carpi ulnaris would be weaker and waste.
Patient presents with permanent claw to all fingers for several years. Can not force to straighten. What is this?
What happens when a disc prolapses?
Nucleus pulposeous herniated and presses on nerve root
What is function of intervertebral discs?
Shock absorbers, allows vertebrae’s to rotate smoothly over each other
When the spine is fully flexed the lateral erector spinae groups are no longer able to extend the spine. Why is this?
Iliocostalis slide anteriorly and become flexors. Spine is only able to extend when body switches of nerve that innervated iliocostalis so it relaxes.
Why does erector spinae muscles decussate at L4-S1?
Increased weightbearing in that area demands more strength
Tensile forced to stabilize the lordosis