Musculoskeletal Growth Injury and Repair – Ligament, Tendon and Bone Flashcards
What are ligaments?
Dense bands of collagenous tissue which span a joint and provide stability
What are ligaments made of?
Type 1 collagen fibres
Fibroblasts
Sensory fibres
Surface vessels
Ligaments are said to have crimping. What does this allow for?
Stretch
->idk think of crimping a pasty allowing it to stretch while cooking in the oven
What is the difference in the composition of tendons and ligaments?
Ligaments have a lower percentage of collagen but higher percentage of water and proteoglycans
Why may ligament ruptures occur?
Force exceeds the strength of the ligament
What is one of the most common sites of a ligament injury?
Ankle joint
Describe the healing process of ligaments.
Initial haematoma
Proliferative phase to produce scar tissue
Remodelling so matrix becomes more ligament like
When would a ligament injury require conservative treatment?
Partial injury
No instability
Poor surgery candidate
When would a ligament injury require operative treatment?
Instability
Expectation of highly functioning ligaments e.g. sportsmen
Compulsory- multiple
->if ligament cannot be repaired, may be replaced, often with tendon taken from the hamstrings.
Which structure is often attached to muscle and comes an a composite unit?
Tendon
Tendons may have a sesamoid bone within the tendon itself. Give an example.
Patella
What do all tendons have?
Some form of tendon sheath
What is the structure of tendon like?
Longitudinal arrangement of tenocytes and type 1 collagen fibres
How does blood supply get into tendons?
Via vincula
How are tendons connected to the tendon sheath?
Via vincula
What holds the tendon to the bone in the fingers?
Strong annular pulleys
What is the function of tendons?
Very strong under tension and flexible- they pull on bones in order to bend joints
What happens if tendons are immobilised for a long period of time?
The water and GAG content falls and reduces strength
Tendons can have problems with degeneration.
Which tendon is known for having problems with degeneration?
Achilles tendon
Sometimes degeneration of the Achilles tendon can be a precursor to what?
Rupture
Which areas of tendon are more likely to degenerate?
Areas with a lower blood supply
Give an example of a common type of tendon inflammation.
De Quervain’s tenosynovitis/tenovaginitis
Which test is used to diagnose de Quervain’s syndrome?
Finklestein’s test
What is enthesiopathy?
Inflammation at the insertion to bone muscle/tendon
->usually at muscle origin rather than tendon insertion
What causes enthesiopathy?
Repetitive movements
->e.g. tennis elbow or lateral humeral spicondylitis
Tennis elbow is a type of enthesiopathy. What type of enthesiopathy is it known as?
Lateral humeral epicondylitis
There can be enthsiopathy at insertion of ligaments. Give an example.
Plantar fasciitis
Osgood Schlatter’s disease is an example of a traction apophysitis injury. What happens here?
The patellar tendon inserts into the anterior tibial tuberosity.
If it pulls on the apophysis rather than the bone, it causes pain and swelling of the apophysis
In which group of people is traction apophysitis like Osgood Schlatter’s disease more common?
Adolescent active boys
What is the management of Osgood Schlatter disease?
If want the pain to stop completely, need to stop the activity causing pain
If want to continue the activity and can put up with the pain, this can be done
What is meant by an avulsion fracture?
Small chunk of bone attached to a tendon or ligament gets pulled away from the main part of the bone.
Where in the body are avulsion fractures more common?
Fingers
->common in rugby players who are grabbing onto shirts and then are suddenly pulled away
What does the treatment of avulsion fractures depend on?
The site of the tendon
What is the treatment for the majority of avulsion fractures?
Operative reattachment of the tendon, often through bone
What is an intrasubstance rupture?
Tear somewhere in the middle of a tendon
Where is a common site of intrasubstance rupture?
Achilles tendon
What are the different mechanisms of a tendon rupture?
- Occurs when pushing off with weight bearing forefoot while extending the knee
Therefore, common with sprint starts or jumping movements - Unexpected dorsiflexion of ankle e.g. slipping into hole
3, Violent dorsiflexion of flexed foot e.g. fall from height
What sign is positive in an Achilles tendon rupture?
Simmond’s test
When is conservative treatment chosen for a ruptured tendon?
When the ends can be opposed- often shows up on an ultrasound
What is the conservative treatment for a ruptured tendon?
Splints or casts
When is operative treatment carried out in a ruptured tendon?
When there is a high risk of rerupture - those who need stronger tendons or have higher activity levels
Which tendons are lacerations or incisions more common in?
FDS
FDP
Who is more likely to get a tendon laceration?
Males > females
Young adults
When may someone get a laceration tendon injury?
Most common when preparing food
What is the treatment for tendon lacerations?
Surgery immediately as issues of with retraction
What allows bones to grow?
Primary ossification centre and then secondary ossification centre
What type of bone is compact?
Cortical bone
What is another name for spongy bone?
Cancellous bone
->usually between two layers of compact/cortical bone
What does cortical bone resist?
Bending and torsion
What does cancellous/spongey bone resist?
Compression
Which type of bone is more biologically active e.g. blood vessels?
Spongey/cancellous bone
Which part of the bone tends to be cortical?
Bone at the diaphysis
What part of the bone tends to be cancellous?
Metaphysis
What is meant by a fracture?
Break in the structural integrity of a bone e.g. crack, break, split, etc.
What is the shorthand sign for a fracture in notes?
#
Name some conditions which weaken bones, most commonly seen in the elderly.
Osteoporosis
Osteomalacia
Metastatic tumours
What happens to the bone in a fracture?
Mechanical and structural bone failure
Disruption of the blood supply
What is different between the healing process of bone compared to everything else in the body?
No scar left in healing of bone, is a regenerative process
There are four stages of bone regeneration.
What are they?
Inflammation
Soft callus
Hard callus
Bone remodelling
What happens immediately after a fracture?
Inflammation stage
Haematoma, fibrin clot, platelets, neutrophils, monocytes and macrophages are released
Made into a ‘soup’ with lysosomal enzymes which bring in new cells to initiate repair
What may we do as doctors which hinder the repair process of a fracture?
Give NSAIDs- reduces inflammation and the ability to repair as this is part of the healing process
Surgery as can cause loss of haematoma which is also required as part of healing process
What does stage two of the soft callus begin?
Begins when the pain and swelling subside
What does the soft callus stage last until?
Lasts until bon fragments are united by cartilage or fibrous tissue
What can be done by doctors in the soft callus stage to help the bone?
Could replace the cartilage during surgery
Could use bone grafts or substitutes so place between gap in fracture
What is the golden standard for treating fractures?
Autogenous cancellous bone grafts
->involves collecting cancellous bone, often from iliac crest, and transplant it
Autogenous cancellous bone grafts are osteoconductive. What does this menan?
It is a structure which allows cells to grow enough to create the bone
->basically, if you fill the gap with this, cells can go on it and bridge the gap essentially
What is allograft bone?
Bone taken from other humans, usually cadavers, and can be used in patients
Can get cortical, cancellous and it can be fresh or prepared
What happens in the stage of hard callus?
Conversion of cartilage to woven bone
This increases rigidity
->woven bone is bone without structure, isn’t cortical or cancellous
What happens in bone remodelling?
Conversion of woven bone into lamellar bone
Medullary canal (found in all bones, nutrients etc, remember first year), is reconstituted
What happens to the healing if the strain on a fracture is too low or high?
Movement is too low or high and fracture ends at different stages of fracture healing meaning the healing will not progress
Delayed union?
Fracture fails to heal in the expected time
List some of the tings which can cause delayed union.
High energy injury- lots of damage to repair
Distraction- fracture ends are far apart and more healing required
Instability
Infection
Steroids
Immune suppressants
Smoking
Warfarin
NSAIDs
Ciprofloxacin
Name some of the drugs which can cause delayed union of a fracture.
NSAIDs
Warfarin
Ciprofloxacin
Immune supressants
When delayed union of a fracture occurs, alternative management should be considered. What may this involve?
Different fixation
Bone grafting
Dynamization (in attempt to get ends of a fracture closer together)
Non-union of a frcature?
Complete failure to heal
Why can non union of a fracture occur?
Failure of fibrocartilage/soft callus to form any bone
Instability- too much movement
Two separate masses of bone are formed but they don’t join together
