MSK Injury Flashcards
What is subluxation?
Partial separation of the articular surfaces of the joint
What is a fracture?
A breach of the integrity of part or the whole of a bone
What is dislocation?
Complete separation of the articular surfaces of a joint
What is a fracture dislocation?
A dislocation where there is also a fracture involving one or more of
the articular surfaces of a joint
What is a sprain?
Stretching of the joint capsule and ligaments, insufficient to produce subluxation or dislocation
What factors determine the mechanism of joint injury?
Strength of bone
Force / energy applied
What are clinical signs & symptoms of a fracture?
Pain Swelling Tenderness Bruising Deformity Crepitus Abnormal Movement
What causes pain in a musculoskeletal injury?
Pain receptors in periosteum
Surrounding nerves activated by swelling
Bleeding into compartment
What is a compound fracture?
Open fracture, break in the skin around broken bone
Outside air can get to fracture site with no barrier
What is a complicated fracture?
Fracture causes damage to other structures eg lungs, major blood vessels, spleen
What is delayed union?
Fracture healing takes longer than expected
What is non union?
Fracture does not unite
What is mal union?
Fracture joins in the wrong alignment
What should be done to diagnose a fracture?
History & Examination X-ray Computerised Axial Tomography Magnetic Resonance Imaging Ultrasound Bone Scan
What are risks with pelvic fractures?
Blood Loss
Abdominal Injury
Nerve Injury
What are common causes of pelvic injury?
Road traffic collisions and falls
What is an open book injury?
Sacroiliac joint no longer attached so pelvis opens up, very unstable
What 3 joints form the pelvic ring?
2 sacroiliac joints
Pubic symphysis
Which fracture of the femur is most likely to lead to avascular necrosis?
Intracapsular neck of femur fracture
What divides intra and extra capsular regions of the femur?
Head and neck of femur - intracapsular
Beyond neck - extracapsular
What types of intracapsular fractures are there?
Subcapital - head of femur
Transcervical - neck of femur closest to head
What types of extracapsular fractures are there?
Basal - closest to neck of femur
Intertrochanteric - between greater and lesser trochanter
What is Shentons line?
Medial edge of femoral neck and inferior edge of superior pubic ramus
In a neck of femur fracture, what position does the affected limb end up in?
Shortened and externally rotated
How can an intracapsular fracture be fixed?
Screws
Prosthesis
How can an extracapsular femur fracture be fixed?
Dynamic hip screw
Which patients are at most risk of avascular necrosis?
Younger patients, greater risk to the blood supply and greater risk of AVN as force of injury probably greater
When is hip at highest risk of dislocation?
Frontal impact with hip flexed as ligaments lax in this position
Eg when sat in car
What can occur within 6 hours of damage to a synovial joint?
Chondrolysis
Avascular Necrosis
These can lead to degenerative arthritis
What is a diaphyseal fracture?
Break in shaft of a long bone
What can be used to fix a femur which has had a diaphyseal fracture?
Intermedullary nail
Metal plate
External fixator
What type of fracture is a patella fracture?
Intra-articular
What can be the results of a patella fracture?
Haemarthrosis
Loss of Knee Extension
Degenerative arthritis can develop
What is a patellectomy?
Surgical removal of the patella
What type of fracture is a tibial plateau fracture?
Intra articular
What is likely to cause a meniscal tear?
Rotation of the femur on a fixed tibia
Flat fixed foot, knee rotation
What can cause tibial shaft fractures?
Direct Trauma
Rotational Strain
What are treatment options for fractures?
Internal or external immobilisation
What is the main symptom of compartment syndrome?
Increasing pain scale
What is ankle diastasis?
Tibiofibular diastasis is separation of tibia and fibular often associated with extensive ligament tears
What can cause Achilles’ tendon rupture?
Overuse or overstress causes degeneration of the blood supply to the tendon and therefore increases risk of rupture
What is Simmonds test?
Examination to test for rupture of Achilles’ tendon
Patient lying face down, feet hanging off edge of bed. Squeeze corresponding calf, positive test - no movement of foot
What is conservative treatment for Achilles’ tendon rupture?
Serial plaster casts
Where does the sacral plexus sit?
Postero-lateral pelvic wall
Describe what the root values of the sacral plexus do?
Hip extension - L5-S1 Hip flexion - L1-L2 Hip adduction - L2-L3 Hip abduction - L4-L5 Knee extension - S1-S2 Knee flexion - L3-L4 Ankle dorsiflexion - L4 Ankle plantarflexion - S1-S2
What muscles are innervated by the tibial part of the sciatic nerve? L4-S3
Hamstrings (L5, S1, S2) Gastrocnemius & soleus (S1, S2) Deep leg flexor muscles (S1, S2) Tibialis posterior & popliteus(L4, L5) Intrinsic muscles of the feet (S2, S3) Plantar cutaneous nerves (L4 – S1)
What do intervertebral discs do?
Resit compression and form a mobile joint
What are intervertebral discs?
Secondary cartilagenous joints present from beneath C2 to above S1
Increase in thickness distally
Cartilage end plate on bone
Annulus fibrosus = Layers of fibrocartilage
Nucleus pulposus = Rubbery central core (GAG)
What are the 3 phases of disc prolapse?
Degeneration and leakage
Protrusion and prolapse
Herniation and extrusion
Where is IV disc prolapse most common? And what nerve does it affect?
Lumbar region
Spinal nerve of IVF one level below
What nerve and artery appears above piriformis and what signs will you see if it’s damaged?
Superior gluteal artery & nerve (L4-S1)
Nerve injury: Trendelenburg Sign, pelvis tilts toward side unsupported
by limb during gait (e.g. right sided paralysis, pelvic tilt to left when left limb lifted off the floor). Trendelenburg gait & lean trunk to affected side when walking to help prevent tilt to the unsupported side
What nerves appear from below piriformis?
Inferior gluteal nerve
Sciatic nerve
What can cause sciatic nerve injury in the gluteal region? And what signs will this cause?
Located posterior to hip joint so at risk with dislocation
Piriformis can compress the nerve
Gluteal stab wound/gunshot wound
Injury causes loss of motor function of the foot, leg and posterior thigh
What will injury to the inferior gluteal nerve cause?
Gluteus maximus gait: trunk lurches back on heel strike of the affected limb to prevent it toppling forward
What will damage to the femoral nerve cause?
Motor Loss / Wasting: Anterior thigh compartment, Iliacus
Functional Issue: No knee extension so knee flexion at rest, Weakened hip flexion, Problems with stairs/inclines/rising from seated position
What can cause damage to the femoral nerve?
Compressed on iliacus during childbirth
Femoral triangle
Subsartorial canal
Saphenous nerve in knee surgery or long saphenous vein stripping
What will be seen with an obturator nerve injury?
Motor Loss/Wasting: Medial thigh compartment, Adductors, Gracilis
Functional Issue: Instability during stance & gait, Centre of gravity shifts laterally during gait, Wide based gate, Lack of propulsion during running, Groin pain
Where can the obturator nerve be damaged?
Pelvic brim (childbirth) Pelvic cavity (surgery) Fascial entrapment
What will be seen with a sciatic nerve injury?
Motor Loss/Wasting: Posterior thigh compartment, Leg (all), Foot (all)
Functional Issue: Limb relatively useless, Impaired hip extension, Very weak knee flexion, Absent ankle & digit plantarflexion & dorsiflexion
What can be seen with a common fibular nerve injury?
Motor Loss/Wasting: Anterior & lateral leg compartments
Functional Issue: Absent dorsiflexion = foot drop, Absent ankle eversion = prone to inversion injury/sprain/#
Where can the common fibular nerve be injured?
Gluteal region as part of sciatic nerve Posterior hip dislocation Posterior thigh Popliteal fossa (inferior to biceps tendon) Lateral aspect of fibula head
What can be seen with tibial nerve injury?
Motor Loss/Wasting: Posterior leg compartment, Intrinsic foot muscles
Functional Issue: Weak plantarflexion, Minimal arch support – prone to pes planus, Digits splay on weight-bearing
Where can the tibial nerve be injured?
Gluteal region
Posterior hip dislocation
Popliteal fossa
Posterior to the medial malleolus in the tarsal tunnel
Which of the bursae around the knee is continuous with the joint?
Suprapatellar
What does bone repair require?
Stability of the Fracture
Vascularity
What structures are at risk from clavicle fracture?
Brachial Plexus
Subclavian vein
What is axillary vein thrombosis?
Acute swelling and pain in upper limb due to occlusion of axillary and/or subclavian veins by thrombus
May occur as primary phenomenon or result of placement of an indwelling venous catheter, thrombophilia or thoracic outlet syndrome
What are examples of Proximal Humeral Fractures?
Greater tuberosity
Anatomical neck
Surgical neck
Head
What will a supraspinatus rotator cuff injury result in?
Unable to initiate abduction
Passive abduction possible
Increased pain after 45 degrees
What signs might you see after humeral shaft fracture?
Wrist drop
Numbness at base of thumb due to radial nerve damage
How do you manage a shaft of humerus fracture?
U slab cast
Aeroplane splint
What nerve and artery injuries can be associated with supracondylar humerus fractures?
Brachial artery
Median nerve
Anterior interosseus nerve
Will have issues making an OK sign
What are the 5 Ps of compartment syndrome?
Pallor Pulselessness Paraesthesia Paralysis PAIN
What is Volkmann’s Ischaemic Contracture?
Permanent flexion contracture of hand at wrist, claw-like deformity of hand and fingers, more common in children. Passive extension of fingers is restricted and painful, fingers white, blue and cold and radial pulse absent
Caused by any fracture in elbow region but commonly due to supracondylar fracture of humerus
Results from acute ischaemia/necrosis of muscle fibres of flexor muscles, especially FDP and FPL which becomes fibrotic and short
Obstruction of brachial artery near elbow: improper use of a tourniquet, plaster cast, compartment syndrome, fracture of forearm bones which cause profuse bleeding from major vessels
What is a Monteggia Fracture?
Dislocation of radial head with a forearm fracture of ulna
Who is most at risk of De Quervains?
Female > Male
30 - 50
Pregnancy
Occupational factors
What is Finkelstein’s Test?
Used to diagnose De Quervain’s tenosynovitis
Grasp thumb and ulnar deviates the hand sharply
Sharp pain occurs along distal radius De Quervain’s tenosynovitis likely
What is the management plan for De Quervains Tenosynovitis?
Rest
Steroid injection
NSAIDs
What can be complications of tendon rupture?
Infection
Adhesions
What is a Mallet Finger?
End of finger flexed towards palm and cannot straighten
Usual cause is injury to end of finger which tears extensor tendon
Common injury when trying to catch a fast, hard ball. Catch missed slightly then ball hits straight finger. Forced flexion injury
What clinical examination findings would you look for in a suspected fracture?
LOOK : Deformity, bruising, wounds, pallor, Any other injuries?
FEEL: Any pain?(before prod them), Temperature, crepitus, oedema, distal sensation, cap refill
MOVE: Flexion and extension passively and actively against resistance (MRC Power grading 0-‐5)
What is a Mallet finger?
Mechanism: sudden, forceful flexion of DIP join in an extended digit
Presentation: deformity and inability to extend DIP
Types: A- pure extensor tendon rupture, B- avulsion of tiny fragment from extensor tendon insertion, C- a larger bony fragment(>20% articular surface) +/-‐ subluxation of DIP joint
What is the management plan for a Mallet finger?
Types A & B: splint in extension(usually for approx. 6 weeks)
Type C: sometimes requires surgical fixation
What are distal radial fractures?
Mechanism: usually fall onto outstretched/ flexed hand, higher trauma in younger adults than older/osteopaenic patients
Presentation: Deformity-‐ Dinner fork deformity (with Colle’s fractures) or Garden spade deformity (with Smith’s)
What are management strategies for distal radial fractures?
Non-‐surgical: For stable injuries,+/- manipulation and cast immobilisation may be sufficient (6 weeks in cast)
Surgical: MUA & K wires, ORIF
What is management strategy in an acute onset carpal tunnel syndrome after wrist fracture?
Release any external pressure- i.e. casts, bandages
Elevate
Re-‐review
If persists may require surgical decompression
What are supracondylar fractures and who are they most common in?
Common in children
Mechanism: fall onto outstretched arm
Presentation: pain, deformity and occasionally neurovascular deficit
Classified according to amount of displacement
What is management strategy for supracondylar fractures?
Attempt to put into an above elbow plaster cast and re-examine neurovascular status
If still doubt, best practice to manipulate fracture in theatre +/-‐ fixation (usually using wires)
The most common nerve to be injured is the anterior interosseous (median nerve), followed by the radial nerve. The brachial artery is also at risk. Ask them to make OK sign with finger to test this
What nerve is at risk during a shoulder dislocation?
Axillary nerve stretched which causes neuropraxis
What is management strategy for glenohumeral dislocation?
Must be reduced and initially immobilised in sling
Will usually require physiotherapy as part of rehabilitation
What root supplies form the Musculocutaneous nerve?
C5-7
What root supplies the median nerve?
C5-T1
What root supplies the Axillary nerve?
C5-6
What root supplies the ulnar nerve?
C8-T1
What root supplies the radial nerve?
C5-T1
Which nerves of the brachial plexus are supplied by C5-6?
Dorsal scapula nerve: rhomboid and levator scapulae
Suprascapular nerve: supra and infraspinatus
Lateral pectoral nerve: clavicular head of pec major
Musculocutaneous nerve
Axillary nerve
What does the medial pectoral nerve supply?
Head of pec major and pec minor
Which compartments are affected if the Musculocutaneous nerve is affected?
Loss of anterior arm compartment muscles
Which compartments are affected if the axillary nerve is damaged?
Loss of deltoid & teres minor
Can be caused by Dislocation of shoulder and # surgical neck humerus
Which compartments are affected if the radial nerve is damaged?
Loss of posterior arm & posterior forearm compartment muscles
Can be caused by # humeral shaft through spiral groove or dislocated/# head of radius affecting posterior interosseous branch
Which compartment is affected if median nerve is damaged?
Loss of most anterior compartment forearm muscles, thenar muscles and lumbricals 1 & 2
Can be caused by Stab to medial arm or anterior wrist
Which compartment is affected if the ulnar nerve is damaged?
Loss of most small muscles of hand
Can be caused by # of medial humeral epicondyle or injury to anterior wrist by pisiform
How and where can the median nerve be injured?
Medial arm or cubital fossa puncture wound/laceration
Pronator teres
Forearm prior to carpal tunnel (defence wound, suicide attempt)
Carpal tunnel (compression)
What does the median nerve supply?
Arm = Nothing
Forearm = EVERYTHING IN THE ANTERIOR FOREARM Except - FCU & FDP to digits 4 & 5
Hand =Thenar muscles & lumbricals to digits 2 & 3
What symptoms will be seen if the median nerve is injured at the elbow?
Can’t make fist with digits 2&3 (hand of ‘benediction’)
No active flexion of IP joints of digits 1,2 & 3
Weaker flexion of digits 4&5 = No FDS but FDP from ulnar nerve
No forearm pronation
Weak wrist flexion that deviates to adduction (FCU = ulnar nerve)
Thenar wasting & thumb opposition not possible
Thumb laterally rotated & adducted (looks like a finger)
What symptoms are seen if the median nerve is injured at the wrist?
Thenar wasting & thumb opposition not possible
Thumb laterally rotated & adducted (looks like a finger)
Digits 2 & 3 lag in fist making as lumbricals 1 & 2 paralysed
Which area of skin is spared in a carpal tunnel lesion of the median nerve?
Palm
How and where can the ulnar nerve be injured?
Medial epicondyle (fracture / compression) Wrist superficial to retinaculum (Guyon’s canal)
What does the ulnar nerve supply?
Arm = NOTHING Forearm = FCU & FDP to digits 4 & 5 Hand = ALL INTRINSIC MUSCLES, Except - Thenar & Lumbricals (digits 2 & 3)
What do interossei and lumbricals do?
Balance crude powerful pull of long extensors and flexors
Fine control of MCP joint - antagonists of crude extensor action
What symptoms will be seen with ulnar nerve damage at the elbow?
No flexion of DIP joint of Digits 4 & 5 = Lack of FDP
Wrist abducts on flexion = Lack of FCU
No digit ab-or adduction (except thumb abduction)
Some clawing of digits 4 & 5 at rest = loss of lumbricals & interossei Loss of most intrinsic hand muscles
Hypothenar & interosseous wasting (guttering on dorsal hand)
What symptoms will be seen with ulnar damage at the wrist?
Loss of most intrinsic hand muscles
Hypothenar & interosseous wasting (guttering on dorsal hand) Pronounced clawing of digits 4 & 5 worse as FDP still works and therefore exacerbates IP joint flexion - ulnar paradox, clawing worse with wrist damage than elbow
What is the ulnar paradox?
Damage at wrist results in worse clawing and more noticeable symptoms than damage at the elbow due to the function of FDP exacerbating the claw when it is still working in wrist damage
How and where can the radial nerve be injured?
Axilla (shoulder dislocation, crutch, asleep over upper limb) Spiral groove (humeral fracture, compression (sleeping arm) Head/neck of radius (posterior interosseous nerve branch)
What does the radial nerve supply?
Arm: Posterior compartment
Forearm: Posterior compartment
Hand: Nothing
What symptoms will be seen if the radial nerve is damaged at the axilla?
All function lost No elbow extension Wristdrop No digit extension Sensory loss on dorsolateral forearm & hand
What symptoms will be seen if the radial nerve is damaged at the spiral groove?
Elbow extension preserved but weakened Wristdrop No digit extension Weak thumb abduction Sensory loss on dorsolateral forearm & hand
What symptoms will be seen if the radial nerve is damaged at the radial head?
Elbow extension normal Minimal wrist drop (as ECR supplied earlier) Digit extension weak/absent Weak thumb abduction No sensory loss - motor nerve
Which nerve is at risk in axillary surgery?
Long thoracic supplying serratus anterior
How and where can the Musculocutaneous nerve be damaged?
Trauma around coracoid
Associated with C5/C6 plexus damage
What does the Musculocutaneous nerve supply?
Arm: Anterior compartment
Except part of brachialis = radial nerve
What symptoms occur if the Musculocutaneous nerve is damaged?
Loss of powerful elbow flexion
Weakened supination
Weak flexion as brachioradialis, part of brachialis (radial n.) and forearm flexors from the common flexor origin (median & ulnar n)
Sensory loss over lateral forearm (C6)
Where is the damage in Klumpke’s Palsy? And what can cause it?
C8 & T1
Upward traction of upper limb
Cancer at lung apex / compression via cervical rib
Affects parts of ulnar & median nerves
What are the symptoms of Klumpkes palsy?
Paralysis & wasting of all small muscles of hand
Clawing of digits 2-5 at rest due to unopposed action of extensors on MCP joint & long flexors on IP joints
Anaesthesia = medial elbow, forearm & arm
What is Erb’s palsy and what can cause it?
C5 & C6 / upper trunk via forced separation of neck from shoulder
Stab wound to neck or iatrogenic
Results in ‘waiters tip’ appearance of upper limb
What are symptoms of Erb’s palsy?
Loss of C5 & 6 = Axillary, suprascapular, dorsal scapula, lateral pectoral & musculocutaneous nerves
Medially rotated shoulder = loss of supra- & infraspinatus, unopposed medial rotation action from sternal head of pec major
Limp & loss of shoulder contour = loss of deltoid
Pronated forearm = loss of biceps brachii
Partial wrist drop/flexion at rest = Loss of extensor carpi radialis
Anaesthesia over C5 & C6 dermatomes (lateral arm & forearm)
