Pathology Flashcards
Types of bone fracture
- Transverse
- Spiral
- Oblique
- Comminuted
- Avulsion
- Open/closed
Clinical features fractures
- pain
- deformity
- reduced ROM
Cause of periosteal injury
direct blow, bleeding under the periosteum
Wolff Law
Bone remodels in direct response to the force applied
Define stress fracture
microfracture due to repetitive loading that, over time, exceeds bone’s intrinsic ability to repair itself
2 mechanisms for bone overload
- Impact forces e.g. metatarsal in marching
- muscle pull e.g. neck of femur in runner
Function of cartilage
- Joint lubricator
- shock absorber
3 types of cartilage
- Hyaline cartilage (covers joint surfaces)
- Fibrocartilage (knee meniscus, vertebral disc)
- elastic cartilage (outer ear)
What is osteochondral injury
Damage to articular cartilage +/- subchondral bone
What is the issue with osteochondral injury?
Poor healing capacity because of inadequate blood flow (nutrition via diffusion from synovium, aided by joint loading)
Articular cartilage overuse sequence
Microscopic inflammation –> softening –> fibrillation –> fissuring –> gross disruption
What is osteochondritis dessecans
Separation of bone + cartilage from normal surrounding bone and cartilage
Types of muscle contraction
- concentric = activity while muscle is shortening
- eccentric = activity whilst muscle in lengthening
- isometric = activity with no change in muscle length
- isotonic = movement occurring at equal force throughout range
- isokinetic = movement occurring at equal speed throughout range
How are muscle strains/tears classified?
Grade 1-3
Grade 1 muscle strain- pathology
- small number of muscle fibres torn
- fascia intact
- minimal bleeding
Grade 1 muscle strain- clinical signs
- mild pain
- full ROM
- full strength
Grade 2 muscle strain- pathology
- significant number of muscle fibres torn
- increased bleeding
most common joint overuse injury
osteochondritis dessicans
most common joint overuse injury
osteochondritis dessicans
grade 2 muscle sprain/tear- clinical signs
- increased pain
- swelling
- decreased ROM + strength
- palpable haematoma
Grade 3 muscle tear- pathology
complete tear, usually at the musculotendinous junction
Grade 3 muscle tear- clinical signs
+++ bleeding and swelling
no active contraction
What is a contusion
direct blow causes bleeding and haematoma formation (ie a bruise)- eg thigh contusion common in football
what can repeated quad contusions lead to?
myositis ossificans
3 common muscle overuse injuries
1) Focal fibrosis- repetitive
2) Chronic exertional compartment syndrome (CECS)
3) DOMS
Focal fibrosis- aeitiology
microtrauma –> chronic inflammation + adhesions
chronic exertional compartment syndrome- aeitiology
exercise –> increases intra-compartment pressure (build up of metabolites) –> tight fascia limits expansion –> impaired blood supply –> ischaemia –> pain
DOMS- aetiology
eccentric exercise –> inflammatory cell/metabolite build up
Clinical signs of myofascial pain
- v tender point in taught band of muscle
- hardening of muscle upon trigger point palpation- hard nots beneath the skin
- subjective weakness of involved muscle
- referred pain from trigger points
(note- shared symptoms with fibromyalgia but this is usually also associated with fatigue)
Classic history CECS
- Squeezing/cramping/aching/burning, typically begins within 15-20 minutes of an exertional type activity
- Well-localised to a specific compartment
- often bilateral
- Pain/symptoms disappear quickly after the cessation of activity.
- Focal neurological findings, i.e., decreased sensation, paresthesias, or weakness
How is CECS diagnosed?
- Hx- clinical examination is normal
- 1o = measurement of Intra-compartment pressure
Mx of CECS
NSAIDs
Botulinum toxin injections
Gait training
Open fasciotomy if refractory to treatment
2 most common sites for tendon rupture
- site of least blood supply- eg 2cm above achilles tendon insertion
- musculotendinous junction
3 commonest forms of tendinopathy + an example of each
- Tendinosis- collagen degeneration, neovascularisation eg patella/achilles
- Tendinitis- inflammation of tendon eg inflammatory arthritides
- Paratenonitis- inflammation of connective sheath
eg de Quervain’s tenosynovitis in rowers
bursa function
facilitate movement of tendon over bony surface
2 categories of bursitis
- acute/traumatic- due to direct knock. causing bleeding into bursa
- overuse - eg subdeltoid bursitis, prepatellar bursitis
bursitis clinical findings
localised pain and tenderness over a bursa
may be swelling if the bursa is superficial
Tx bursitis
- conservative- rest, analgesia
- corticosteroid injections if Rx
- excision of bursa is still Rx
3 common nerve injuries in sport
- Acute- neuropraxia- due to direct trauma- tingling, parasthesia, pain, weakness
- Acute/chronic- entrapment eg from prolapsed intervertebral disc impinging on nerve root
- Chronic- adverse neural tension- irritation of nerve due to local inflammation causing pain or stretching of nerve
eg RSI/carpal tunnel
