Locomotor: PBL 1 (Glenoid Labral/SLAP Tear) Flashcards
Why may a labral tear not show up on x-ray?
Soft tissue, so may be distorted by the clear white bone in the surrounding region. In addition, the labrum is a ligament which lies beneath the anterior surface of the humerus so this layer would be obstructed by structures in front..
What is the action of the biceps brachii muscle at the glenohumeral joint?
Stabilises the shoulder joint
What is the action of the biceps brachii muscle at the humero-ulna joint?
Flexion of the elbow
What is the action of the biceps brachii muscle at the proximal radio-ulnar joint?
Supination
What is the normal ratio of movement at the glenohumeral joint and the physiological scapulothoracic joint
Glenohumeral joint 2:1 scapulothoracic joint.
What is a SLAP lesion?
Injury to the glenoid labrum, SLAP = superior labral tear, anterior to posterior
What is the glenoid labrum?
Fibrocartilaginous ring rim attached around the margin of the glenoid cavity
What is an arthrogram?
An X-Ray of the inside of a damaged joint after iodine has been injected into the joint
What are the rotator cuff muscles?
Group of muscles and their tendons which act to stabilise the shoulder: infraspinatus, supraspinatus, subscapularis and teres minor
What is diclofenac?
NSAID (non-steroidal anti inflammatory drug) which is used to reduce pain and inflammation
What is meant by ‘nerve block’?
Production of anaesthesia in part of body by injecting substance into nerves which supply an area
What is a type II SLAP lesion?
Separation of the superior portion of the glenoid labrum and tendon of biceps brachii from the glenoid rim
What is a thrombosis?
The formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system
What type of joint is they glenohumeral joint?
Synovial ball and socket
What is the antecubital fossa?
a fossa in the anterior elbow which is bound medially and laterally by the humeral origins of the flexor and extensor tendons of the forearm, and superiorly by an imaginary line between the humeral condyles
Define ‘paraesthesia’
an abnormal sensation, typically of tingling or pricking (pins and needles), which is mainly caused by pressure on/damage to peripheral nerves
What is a Doppler ultrasound?
Non-invasive test used to estimate blood flow through blood vessels by bouncing high-frequency sound waves off of circulating red blood cells
What is DVT?
Deep vein thrombosis - thombrosis in a vein lying deep below the skin, usually in the legs and often precipitated by immobility during illness of long-distance travel
What is enoxaparin sodium used for?
It’s an anticoagulant which is used to prevent DVT or to treat acute DVT
What is warfarin used for?
Anticoagulant usually used in prevention of thrombosis
What allows the large freedom of movement at the shoulder joint?
Laxity of the articular capsule and the large humeral head in comparison to the shallow glenoid cavity
What are the chief flexors of the shoulder?
Pectoralis major and deltoid (anterior)
What are the chief extensors of the shoulder?
Latissimus dorsi and deltoid (posterior)
What are the chief shoulder abductors?
First 10 degrees is supraspinatus, thereafter is deltoid
What are the chief shoulder adductors?
Mainly gravity, but also latissimus dorsi and pectoralis major
What is the chief medial rotator of the shoulder?
subscapularis
What is the chief lateral rotator of the shoulder?
Infraspinatus and teres minor
What is often the cause of a SLAP tear/lesion?
Initial forceful movement most commonly associated in sports with a pull on the arm, weightlifting, throwing injury or a tackle
What type of sports increase the risk of a SLAP tear?
Overhead and contact sports
Describe a type 1 SLAP lesion
Partial tear, degeneration of superior labrum, edges of ligament are rough and fray but labrum not completely detached. TREATMENT: debride edges of labrum
Describe a type 2 SLAP lesion
Superior labrum completely torn off glenoid leaving gap between articular cartilage and labral bone attachment
Describe a type 3 SLAP lesion
Bucket-handle tear; torn labrum hands into the joint causing locking and popping
Describe a type 4 SLAP lesion
Labral tear extends into long head of biceps tendon
What is the most common type of SLAP tear?
Type 2
How can SLAP tears be distinguished from acromioclavicular joint problems?
SLAP tears have pain with biceps loading (going down in bench press) whereas in AC joint issues, pain usually felt when pressing out at the end of a bench press
What are the common symptoms of a SLAP tear?
Pain at the top of shoulder, clicking and pain with overhead activities
What clinical test can be performed to diagnose a SLAP tear?
O’Briens test
Describe O’Briens test
Place patients arm straight in front of them (elbow extended fully, then slightly adduct the arm into the midline (15 degrees), then maximally internally rotate the arm and push down on arm (get them to resist) and repeat in supination
What is a positive O’Briens test?
If there is pain elicited by the first manoeuvre (full internal rotation) that is reduced or eliminated by the second manouvre
How can O’Briens test distinguish between ACJ and SLAP tears?
ACJ - there will be pain in the ACJ region
SLAP - there will be pain or clicking deep in the glenohumeral joint
What treatments may be used for a SLAP tear?
Physiotherapy, diclofenac (NSAID) and surgery
Describe how physiotherapy can help to treat a SLAP tear
Promotes growth of rotator cuff muscles to try and increase stability
Describe how diclofenac can help to treat a SLAP tear
NSAID used to reduce swelling and allow healing
Describe how surgery can help to treat a SLAP tear
Glenoid cavity and labrum are roughened to increase contact surface area and promote re-growth, bone anchor locations selected, glenoid is drilled for anchor implantation, anchors inserted into glenoid, suture component of implant is tied through labrum and knotted –> labrum now in tight contact with glenoid surface
What are the spinal roots of the brachial plexus?
C5-T1
What are the 5 terminal branches of the brachial plexus?
Lateral cord - musculocutaneous nerve
Posterior cord - axillary and radial nerves
Medial cord - median and ulnar nerves
Describe the arterial supply to the upper limb
See anatomy diagram
Describe the venous supply to the upper limb
See anatomy diagram
Describe the nervous innervation to the upper limb
See anatomy diagram
What is the main cause of DVT?
Poor blood flow, as when blood flow is slow then it can pool, giving cells a greater chance to stick together and start clotting
Why does surgery increase the likelihood of developing DVT?
If surgery reduces blood flow to a part of your body OR and major surgery on legs/belly/chest as there will be bed rest (stagnant blood flow) AND the procedure could set tissue, protein and fats loose in the veins and if the vein wall gets accidentally damaged, it can release chemicals that trigger blood clotting
Describe what is involved in conducting an interscalane brachial plexus nerve block
The interscalene block is performed by injecting local anaesthetic to the nerves of the brachial plexus as it passes through the groove between the anterior and middle scalene muscles, at the level of the cricoid cartilage.
Describe the cause of reduced elbow flexion after DVT?
Compression of the median nerve in the antecubital fossa
Describe the cause of mild paraesthesia and weakness of the muscles that flex the wrist and fingers
Compression of the median nerve
How is DVT diagnosed?
Doppler ultrasound
Describe how a Doppler ultrasound is conducted
A handheld transducer is passed over skin above blood vessel and sends/receives sound waves which bounce off solid objects, including blood cells. Movement of blood cells causes a change in pitch of reflected sound waves - if there is no blood flow then the pitch doesn’t change therefore there is a clot/obstruction
Why is enoxaparin sodium prescribed to treat DVT?
Binds to antithrombin (circulating anticoagulant) to form a complex that irreversibly inactivates clotting factor Xa to prevent any further clot formation
Why is enoxaparin sodium initially used in treatment instead of warfarin?
Don’t have to be monitored as much and has more immediate effects
