MSK Flashcards
What is a saphenous cutdown and when might it be important?
Great saphenous vein can be located anterior to medial malleolus, skin incision can be made here in emergency situations when difficult to find a vein for venepuncture or cannula insertion e.g. if patient in shock.
Why might a patient experience pain over medial border of foot after a saphenous cutdown
Risk of saphenous nerve damage in procedure, which provides sensory innervation to medial border of foot so pain here if nerve damaged.
Describe a Pott’s fracture
Excessive eversion of foot, pulls on medial ligament, tearing off medial malleolus-fractures. Talus moves laterally, shearing off the lateral malleolus. This can result in breakage of fibula superior to tibiofibular syndesmosis. Posterior margin of distal end of tibia may also be sheared off by talus.
Borders of femoral triangle
Superiorly- inguinal ligament
Medially- medial border of adductor longus muscle
Laterally- medial border of sartorius muscle
Floor- pectineus muscle medially and iliopsoas muscle laterally
Roof- fascia latae (deep fascia)
Borders of axilla
Apex- cervico-axillary canal- lateral border of 1st rib, post. border of clavicle and superior edge of scapula.
Anterior- pectoralis major and minor muscles.
Posterior- latissimus dorsi, teres major and subscapularis muscles.
Base- subcutaneous tissue, concave skin and axillary fascia.
Medial- serratus anterior muscle, ribs 1-4 and intercostal muscles.
Lateral- intertubercular groove in humerus.
Describe the difference between the mid-inguinal point and the mid-point of the inguinal ligament, and state which is used to find the femoral arterial pulse.
MIP: the mid-point between the ASIS and the pubic symphysis. This is used to palpate the femoral artery. MP of IL: the mid-point between ASIS and pubic tubercle, as these are the attachment sites of the inguinal ligament. Femoral nerve located here.
A patient has a +ve Trendelenburg test when standing on their right leg. If they were to stand on their right leg, lifting their left off the ground, which hip would drop down and which side would there be superior gluteal nerve damage.
Their left hip would drop (pelvis on unsupported side descends), and superior gluteal nerve damage on right side, so gluteus medius and minimus weak on supported side.
Aside from superior gluteal nerve damage, give 2 other causes of a +ve Trendelenburg test.
Fracture of greater trochanter and dislocation of hip joint.
Tensor fasciae latae muscle is a flexor of thigh and aids gluteus medius and minimus, but describe one other important function of this muscle.
Tenses iliotibial tract which inserts onto lateral condyle of tibia, so knee joint is stabilised, reducing work load of quads when standing and increasing extending force of knee when fully extended. Also supports femur on tibia when standing if lateral sway occurs.
Which ligament gets thinner as descends VC?
Posterior longitudinal ligament.
What test would you use to map dermatomes?
Pin prick test.
What is the significance of the saphenous opening?
A femoral hernia can come through this opening.
What key action cannot be performed, apart from dorsiflexion of foot, if common fibular nerve damage?
Eversion of foot as evertors in lateral compartment of leg, innervated by superficial fibular nerve.
Why must the scapula rotate on abduction of arm above 90 degrees?
Greater tubercle of humerus impinges upon the acromion process of the scapula.
Describe the course of the sciatic nerve
Enters gluteal region via greater sciatic foramen, inferior to piriformis, mid way between PSIS and ischial tuberosity. Descends into thigh vertically at midpoint between ischial tuberosity and greater trochanter. Nerve runs infero-laterally.
Borders of cubital fossa
Roof- bicipital aponeurosis
Floor- supinator and brachialis muscles
Medial border- pronator teres
Lateral border- brachioradialis
Contents of cubital fossa
Lateral to Medial: radial nerve, tendon of biceps brachii, brachial artery, median nerve. (RBBM)
Contents of femoral triangle
Lateral to Medial: NAVY: femoral nerve, femoral artery, femoral vein, femoral canal
Borders of anatomical snuffbox
Medial: tendon of extensor pollicis longus muscle
Lateral: tendons of abductor pollicis longus and extensor pollicis brevis muscles
Floor: scaphoid and trapezium and distal ends of tendons extensor carpi radialis longus and brevis.
Proximal: radial styloid process
Roof: skin
Nerve roots for femoral and obturator nerves
L2-L4
Nerve roots for sciatic nerve
L4-S3
Blood supply to hip
Medial and lateral circumflex femoral arteries derived from the deep artery of the thigh(deep femoral artery), obturator artery and intra-medullary supply?
Name components of axial skeleton
Skull, sternum, ribs, vertebrae and sacrum
Name components of appendicular skeleton
U+L limbs, including clavicles and scapulae, and hip bones.
What is the quadrangular space bordered by and name the nerve that passes through this space. Also describe why there may be loss of sensation over regimental badge area if there is an anterior dislocation of the humerus at the shoulder joint.
Teres major+minor, humerus and long head of triceps brachii.
Axillary nerve
Subglenoid displacement of humeral head into quadrangular space damages the axillary nerve which provides sensory innervation to the regimental badge area via the superior lateral cutaneous nerve of the arm.
What action might a patient not be able to perform and why if an anterior dislocation of shoulder joint?
Abduction of the arm between 15 and 90 degrees as deltoid muscle responsible for this action may be paralysed in an anterior dislocation of shoulder joint as axillary nerve innervating the muscle is damaged.
Name 3 ways in which the axillary nerve may be damaged.
Surgical neck fracture of humerus, dislocation of GH joint, improper use of crutches.
Give nerve roots for axillary nerve
C5, C6
Give nerve roots of musculocutaneous nerve and name the muscles it innervates
C5,C6,C7
Anterior arm compartment: biceps brachii, coracobrachialis, brachialis
How might musculocutaneous nerve be damaged?
What would be the consequence?
Weapon injury to axilla e.g. knife injury.
Paralysis of BBC, and may be loss of sensation over lateral aspect of forearm supplied by lateral cutaneous nerve of forearm, the continuation of the musculocutaneous nerve.
Give nerve roots of radial nerve and describe when it might be damaged
C5-T1.
May be damaged superior to origin of its branches to triceps brachii.
May be damaged in a mid-shaft fracture of humerus where it travels in the radial groove.
May be when deep wounds of forearm, as this can damage the posterior branch of the radial nerve which is an entirely muscular branch.
Define a callus and give 2 of its functions
a fibrocartilaginous structure, which helps to stabilise bone and bind the 2 bone ends together. Fibroblasts undergo metaplasia to form chondroblasts which lay down islets of cartilage around collagen fibres, forming a DCT.
Why might the healing of bone fractures be delayed?
- pre-existing bone disease
- movement so bone unstable
- infection
- intersposed soft tissue
- gross mis-alignment
Define compartment syndrome and state how it can be relieved
condition resulting from swelling of muscles in a limb compartment which raises pressure within compartment so blood supply to muscle cut off, causing ischaemia and further swelling. New blood can’t be supplied to area as arterial pressure becomes greater than pressure supplying blood.
Fasciotomy
Give 4 causes of compartment syndrome
bone fracture, crush injury, tight plaster, extreme exercise
What are the origins and attachments of the biceps brachii muscle?
Long head originates from the supraglenoid tubercle of the scapula whereas short head originates from the coracoid process of the scapula. Both heads insert via a tendon onto the radial tuberosity of the radius.
What are the attachments of the flexor retinaculum at the wrist?
Scaphoid, trapezium(tubercles of both), pisiform and hamate (hook of) carpal bones.
What are the origins and attachments of the biceps brachii muscle?
Long head originates from the supraglenoid tubercle of the scapula whereas short head originates from the coracoid process of the scapula. Both heads insert via a tendon onto the radial tuberosity of the radius.
Which veins does the median cubital vein connect?
The basilic (medially) and the cephalic (laterally) veins.
Which major artery supplies most of the arterial branches to the scapula? If this artery were to be occluded at its mid point, how would blood be allowed to reach the arm?
Axillary artery
Arterial anastomosis/collateral circulation around scapula.
Which veins does the median cubital vein connect?
The basilic (medially) and the cephalic (laterally) veins.
Which major artery supplies most of the arterial branches to the scapula? If this artery were to be occluded at its mid point, how would blood be allowed to reach the arm?
Axillary artery
Arterial anastomosis/collateral circulation around scapula.
Which muscle, acting on scapula, would be affected by injury of spinal accessory nerve?
Trapezius
Give an example of an irregular bone in UL?
Trapezium (carpal bones)
Flat bone in UL?
Scapula
Mechanical functions of bone?
- Support of soft tissues as rigid framework.
- Protection of vital organs
- Movement as anchoring points for muscles and acts as levers at joints.
- Shape given to individual
How do tuberosities, tubercles, ridges and grooves appear on a long bone?
Mechanical forces due to ligaments, tendon, fascia and aponeurosis attachment. Pressure from adjacent structures e.g. nerves and blood vessels, creates grooves.
Physiological functions of bone?
- Storage of salts and minerals, so aids homeostasis.
- Lipid storage in emergencies-yellow marrow
- Supply of blood cells, red marrow-erythropoiesis.
Name causes of a swelling in the popliteal fossa.
- Enlarged lymph nodes
- Popliteal arterial aneurysm
- Popliteal cyst (Baker’s)
- Tumour
- Abscess
What name is given to the regional thickenings of deep fascia at the ankle joint which prevent the tendons of muscles in the anterior compartment from bowstringing out during contraction?
Superior and inferior extensor retinacula.
What is the function of red bone marrow and erythropoietin?
Red BM- erythropoiesis. Erythropoietin- cytokine released by the kidneys in response to a decrease in pO2, and this stimulates rbc production, causing differentiation of common myeloid progenitor cells into rbc.
Define a dermatome
a unilateral area of skin supplied by the sensory nerve fibres of a single spinal nerve root.
Define a myotome
a muscle or group of muscles supplied by the motor nerve fibres of a single spinal nerve root.
Define the 3 classes of joints based on their function and describe each, also giving an example for each.
Synarthrosis- an immovable joint in which bones connected by fibrous tissue e.g. interosseous membrane between radius and ulna=syndesmosis. Also gomphoses-teeth and sutures-skull.
Amphiarthrosis- slightly moveable joint in which bony surfaces separated by hyaline cartilage e.g. epiphyseal growth plates-synchondrosis, or fibrocartilage e.g. pubic symphysis.
Diarthrosis- freely moveable joint with ends of adjoining bones covered in hyaline (articular) cartilage sheet e.g. glenohumeral joint-ball and socket synovial joint.
Give the 7 different types of synovial joint
Ball and socket, condylar, hinge, pivot, saddle, ellipsoid and plane.
Classifly the 3 types of joints in terms of structure and describe them.
Fibrous- articulating bones united by fibrous tissue, virtually no movement e.g. tight union between bones of adult skull.
Cartilaginous- articulating bones connected by hyaline or fibrocartilage. Primary and secondary, primary usually temporary, little movement permitted.
Synovial- freely moveable, skeletal element separated by a cavity, hyaline cartilage covering articulating bone surfaces.
3 main components of all synovial joints
- joint cavity with small amount of synovial fluid
- articular hyaline cartilage covering articulating bone surfaces separated by joint cavity.
- synovial membrane which secretes synovial fluid and lines the outer fibrous layer of the joint capsule.
What factors restrict movement at synovial joints?
Ligaments-these exert a tension e.g. iliofemoral ligament of hip. Muscle tension.
Interference by other structures.
Stability dependent on depth of bony articulations.
Which specific tissues affected in RA and osteoarthritis?
RA: synovium
Osteo: cartilage
What is the significance of a lump being fixed?
Attached to other tissues e.g. muscle, skin or deep fascia. This may indicate an invasive an malignant pathology.
Which nerve supplies the muscles of the lateral compartment of the leg, and name these muscles.
Superficial fibular nerve
Fibularis longus and brevis
Which arteries supply blood to the lateral compartment of the leg?
Perforating branches of the anterior tibial artery and the fibular artery.
What are the functions of the muscle in the lateral compartment of the leg?
Eversion, and assist with plantarflexion.
Name the muscles of the anterior leg compartment, and give the main functions of this compartment.
Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius.
Dorsiflexion of the ankle, inversion of foot and extension of toes. Fibularis tertius performs eversion of the foot.
Which artery supplies blood to the anterior leg compartment?
Anterior tibial artery
Which nerve innervates the muscles of the anterior leg compartment?
Deep fibular nerve
What function does eversion facilitate?
Walking on an uneven surface
Name the extracapsular ligaments of the knee joint
Medial and lateral collateral, patellar, oblique popliteal and arcuate popliteal.
Name the intracapsular ligaments of the knee joint
Anterior and posterior cruciate
Which ligament is the strongest intracapsular ligament of the knee joint?
posterior cruciate
Which muscle contribute to the forming of the calcaneal (achilles) tendon, and where does this tendon insert?
Medial and lateral heads of gastrocnemius, soleus.
Calcaneus bone
Describe varicose veins
In the lower limbs, blood flows from the skin to superficial veins, which drain into the deep veins. Valves prevent back flow of blood. If they become incompetent, the superficial veins can become dilated, and tortuous. There are various soft tissue changes that can occur with chronic varicose veins. Due to the incompetence of the valves, the pressure in the venous system rises. This damages the cells, causing blood to extrude into skin. Further complications can produce a brown pigmentation, and ulceration can occur. Varicose veins can be treated by;
- Surgical movement of the saphenous systems
- Reconstruction of valves
- Tying off the affected valves
Name the 2 articulations of the knee joint and what type of synovial articulations these are.
tibia-femoral articulation:hinge
patello-femoral :plane
Describe the unhappy triad of injuries of the knee joint.
Medial collateral ligament tear, along with tearing of medial meniscus and tearing of the anterior cruciate ligament.Frequently results from blow to lateral side of extended knee or excessive lateral twisting of the flexed knee that disrupts ligament, common in athletes e.g. in basketball, who twist their flexed knees when running.
How might a patient with a scaphoid fracture present?
With pain over the anatomical snuffbox. Fracture may not be visible on an X-ray, but may be around 10 days later when bone resorption has started to take place.