MSK growth and repair Flashcards
What is a ligament
Dense band of collagenous tissue spanning a joint
Connects bone to bone
Gives joint stability
Multiple at joint
What is the structure of a ligament?
Type 1 collagen fibres Contain fibroblasts for communication Contain sensory fibres (proprioception/stretch) Have surface vesells Are crimped allow for stretching
When does a ligament rupture occur?
When force exceeds strength of ligament
Either expected or unexpected
What are the types of ligament rupture?
Can be complete or incomplete
What are the side effects of a ligament rupture?
Pain
Stability loss
Proprioception loss in joint
How does the haemorrhage caused by ligament rupture heal?
Blood clot that is reabsorbed
The replaced with heavy cellular infiltrate
Has hypertrophic vascular response
What happens to the scar tissue produced by a ligament healing?
The disorganised connective tissue matrix becomes more ligament light
Although still has major differences in composition and function
How do you treat a ligament injury?
Conservative or operative
Conservative if parital, no instability or cannot have surgery
Operate on sportsmen If multiple (and therefore compulsary) Joint instability
What are the layers to a tendon?
Collagen bundles covered by endotenon
Make up fascicles covered by paratenon
Make up tendon covered by epitenon
Where are teh blood vessels in a tendon located?
In paratenon
How are tendons connected to their sheath?
By vinicula
What do the tendon sheaths contain?
A synovial lining + fluid for lubrication
What is the function of a tendon?
Flexible and very strong tension to allow for movement
What does immobility lead to?
Reduced water content
Reduced glycosaminoglycan concentration
Reduced strength
What are the types of tendon injury?
degeneration inflammation enthesiopathy traction apophysitis avulsion bone fragment * tear - intrasubstance (rupture) * tear - musculotendinous junction laceration/ incision crush / ischaemia / attrition nodules
What is tendon degeneration?
Intrasubstance mucoid degneration
May be swollen, painful tender
Maybe asymptomatic
What are the symptoms of tendon inflammation?
Swollen Tender Hot Red Positive Finklestein test
What tendons are likely to become inflamed?
EPB
APL
Tendons through common tendon sheath at radial aspect of wrist
What is enthesiopathy?
Inflmmation at insertion to bone
Where is enthesiopathy likely to take place in a muscle?
The muscle origin rather than tendon insertion
Lateral humeral epicondylitis is a common example
What is traction apophysitis?
Where excessive pull by a large tenson causes damage to unfused apophysis
Recurrent load leading to inflammation
Who is likely to get traction apophysitis?
Adolescent active boys
What are some examples of traction apophysitis?
Osgood-Schlatter’s disease
Sever’s disease
Sinding Larsen’s disease
What is avulsion?
Where a structure is forcibly detached from it’s nomral point of insertion
I.e bone/ligament detachment leaving a fragment
How do you treat avulsion
Conservative - limited application
Operative - reattachment /fixation
What is an intrasubstance tendon rupture?
Where the tendon ruptures
Happens when load exceeds failure strength
What are the signs in an achilles tendon rupture?
Positive simmonds test (squeeze test)
Palpable tendon gap
What is a musculotendinous junction tear?
Where the joint between the tendon and its muscle tears
Often partial
How do you treat tendon ruptures?
Conservative - splint/cast Mobilise Operative - ends cannot be opposed High risk of rereupture High activity
How do you treat lacerations of tendons?
Repair surgically and quickly
More common in young adults and men
What is the structure of a nerve?
Axons, coated in endoneurium, bundled into fascicles which are bundled into form a nerve
Fasciles covered in Perineurium
Epinerium for nerve
What is the speed of an Aa neurone?
60-100m/s
What is the function of an Aa neurone?
Large motor axons
Muscle stretch + tension seconsry axons
What is the speed of Ab neurones?
30-60m/s
What is the function of an Ab neurone?
Touch
Pressure
Vibration
Prioprioception
What is the function of an Ay neurone?
Gamma efferent motor neruones
What is the speed of an Ay neurone?
15-30m/s
What is the function of an Ad neurone?
Sharp pain
Light touch
Temperature
What is the speed of an Ad neurone?
10-15m/s
What is the function of a B neurone?
Sympathetic preganglionic motor neurones
What is the speed of a B neurone?
3-10m/s
What is the speed of a C neurone?
<1.5m/s
What is the function of a C neurone?
Dull, sching or burning pain
Temperature sensation
What are teh types of periheral nerve injury?
Compression
Trauma (direct or indirect)
What are some examples of compression injuries?
Entrapment
“Classical conditions”
Carpal tuinnel syndrome (median nerve at wrist)
Sciatic (spinal root by intervertebral disc)
Mortons neuroma (digital nerve in 2nd/3rd webspace of foot)
What are the three types of trauma injury?
Neurapraxia
Axontmesis
Neurotmesis
What is neurpraxia?
A reversible conduction block caused by stretching or bruising
There is local ischaemia and demyelination
Good prognosis
What is axonotmesis?
Disruption of axons but endoneurium intact
Often due to being stretched, crushed or direct blow
What is the prognosis of axontmesis?
Okay - sensory often recover better than motor
May not go back to normal
What follows axonotmesis?
Wallerian degeneration
What is neurotmesis?
A complete nerve division, often caused by laceration or avulsion
Endoneural tubes disrupted
What is the prognosis of neurotmesis?
No recovery unless repaired (graft/suture)
Even under repair “miswiring” common
Prognosis poor
What is a closed nerve injury?
Associated with nerve injuries in continuity (neuroprains/axontmesis)
Spontaneous recover possible
When is surgery indicated in a closed nerve injury?
After 3 months if no recovery identified
What is an open nerve injury?
Frequently nerve division (often knife etc)
Distal portion dies (wallerian degneration)
How do you treat an open nerve injury?
Early surgery
What are the clinical features of a nerve injury?
Dsysaethesia (in sensory neurones)
In motor - paresis/paralysis + wasting
Dry skin due to no sweat gands
Reflexes - diminished or absent
How do nerve injuries heal?
Distal nerve dies under wallerian degeneration
Myelin sheath degrades
Proximal axonal budding occurs after 4 days
Regeneration at 1mm/day
Pain is first modality to return
What is the prognosis for recovery from a nerve injury?
Dependant on if pure or mixed
How distal the lesion is (further the better)
What is Tinels sign?
Tap over site of nerve
Paraesthesia felt as distially as nerve recovered
When would you do a direct nerve repair?
In laceration
No loss of nerve tissue
Bundle repair
When would you use a nerve graft?
In nerve loss
Or late repair
Use sural nerve often
What is the rule of 3?
Immediate surgery within 3 days for sharp/clean injuries
Early surgery within 3 weeks for blunt injuries
Delayed (3 months) surgery for closed injury
What are the differences between cortical and cancellous bone?
Cortical bone found in diabpysis of bone
Resists bending + torsion
Circumfrentially laid
Less biologically active
Cancellous
Found in metaphysis of bone, resists compression
Site of longitudinal growth
Biologically active
What is the diaphysis?
The shaft of a bone
What is the metaphysis and epipphysis?
Metamysis is flare at end of shaft
Epiphysis is on the joint side of physis
Where is the medullary canal found?
In the central cavity of the bone
What is a fracture?
Break in continuity of bone
Could be crack, break, split, crumpling or buckle
What can lead to a fracture (the bone failing)?
High energy transfer in normal bones
Repetive stress in normal bones (stress #)
Low energy in abnormal bones (osteoporosis, ostemalacia etc)
What happens to the bone in a fracture?
Mechanical + structural failure of bone Disruption of blood supply Regenerative process (no scar)
What are the four stages to fracture repair?
Inflammation
Soft callous stage
Hard callous stage
Bone remodelling
What happens in the inflammation stage of fracture healing?
Begins immediately after # Forms haematoma and fibrin clot Lots of blood cells and by products f cell death Angiogensis starts if hypoxic Osteogenic induction of cells
How might we help the inflammation stage of fracture healing?
NSAIDs
Treat aemotoma in open fractures with surgery
What is the soft callus stage of fracture healing?
Begins when pain/swelling subside
Lasts until bony fragments united by fibrous tissue/cartilage
Some stability of fracture
Continued increase in vascularity
How might we assits the soft callus stage of fracture healing?
Replace cartilage with demineralised bone matrix
Use bone graft
What is the hard callus stage of fracture healing?
Conversion of cartilage to woven bone
Typical in long bone fracture -
Increased rigidity although obvious callus
What is the bone remodelling stage of fracture healing?
Conversion of woven bone into lamellar bone
Medullary canal reconstituted
Bone responds to loading characteristics
What ca cause delayed union?
High energy union Distraction (increased osteogenic jumping) Instability Infection Steroids Immune suppresants Smoking Warfarin NSAIDs Ciprofloxacin
What is non-union?
Failure for fracture to heal
What can cause non-union?
failure calcification of fibrocartilage
instability
-excessive osteoclasis
abundant callus formation
pain + tenderness
persistent fracture line
sclerosisWhat is an open fracture?
Direct communication between external environent and fracture
Why are open fractures significant?
Increased infection rate
Soft tissue complications common
Higher energy injury
Long term morbidity
What are the types of open fracture?
type 1 - clean and simple, <1cm
Type 2 - wound 1cm+ with soft tissue damage, simple fracture pattern
Type 3 - extensive soft tissue damage, complex fracture pattern
What are the features of a type 3 open fracture?
High energy
wound 10cm + often
Extensive soft tissue damage
What are the subtypes of type 3 open fracture?
A - adequate periosteal coverage (not grossly contaminated)
B - tisse loss requiring soft-tissue coverage procedure (graft etc) - extensive muscle damage
C- vascular injury needing repair - neurovascular complication
What are the tibial fracture patterns?
Transverse/short oblique tibial fractures with fibular fractures
Tibial fractures with communication with fibular fractures
Segmental tibial fractures
Fracutes with bone loss (either extrusion or debridement)
What are soft tissue injury patterns in a tibial fracture?
skin loss that tension free closure not possible
Degloving
Injury to muscles requiring excision via wound extensions
Injury to 1+ major arteries in leg
How do you manage a complex open fracture?
Full advance trauma life support assesment + treatment
Tetanus + antibiotic prophylaxis
Repeated neurovascular status examination
Wounds only handled to remove gross contamination
What are the indications for surgery?
Polytraumatise patient Marine/farmyard environment Gross contamination Neurovascular compromise Compartment syndrome
When debriding and fixing (surgery) what is looked for?
4 Cs Colour Contraction Consistency Capacity to bleed
Who deals with skin coverage issues?
Plastic surgeons
Grafting
When is amputation considered?
Insensate limb/foot
Irretrivable soft tissue or bony damage
Other life threatening issues
dual constultant decision
What is a dislocation?
Complete joint disruption
What is subluxation?
Partial dislocation (not fully outside joint)
How do you diagnose dislocation?
Clinically + radiological
Associated injuries - neurovasculat damage, soft tissue/msk damage
How do you treat dislocation
Relocation
Surgery if required
What dislocations can occur at the shoulder?
Anterior - squared off
Posterior - locked in internal rotation
What dislocations can happen at the elbow
Posterior - olecranon prominent posteriorly
What dislocations can happen at the hip?
Posterior - Leg short, flexed
Internal rotation
Adduction
What dislocations can occur at the knee?
Anteroposteriorly
Loss of normal contour, extended
What dislocations happen at ankle?
Lateral most common - externally rotated
Prominent medial malleolus
What locations occur at subtalar joint?
Lateral most common - displaced calcis (heel)
