Principles of Joint Surgery Flashcards
synarthroses
immovable: joints between bones of skull
what are indications to perform joint surgery?
- osteoarthritis/synovitis
- osteochondral fragments
- osteochondrosis/dissicans (with flap)
- trauma
- sepsis
- diagnostic exploration if lameness not improving
diarthroses
movable
what is the central structure constituting joint function?**
articular cartilage!
anatomy of a joint
- synovial membrane: secretes synovial fluid that allows motion of joint
- periarticular ligaments and joint capsule
- subchondral bone
- articular cartilage
- maybe menisci, TMJ etc
articular cartilage function ***
- provides frictionless movement of joint
T/F: articular cartilage lacks vascular/lymphatic/neural supply**
true
articular cartilage summary**
- central structure for joint function: provides frictionless movement of joint
- lacks vascular/lymphatic/neural supply
- depends on diffusion for nutrients and waste removal
- consists of chondrocytes, ECM (collagen, water, etc)
- limited ability for shock absorption
what are the zones of articular cartilage?**
- superficial/tangenital zone: 10-20%
- intermediate/transitional zone: 40-60%
- deep/radiate zone: 30%
- calcified zone
- tidemark
T/F: articular cartilage is a primary component of shock absorption
FALSE it has limited ability for shock absorption
what are proteoglycans
- single protein core where glycosaminoglycans side chains attach
**polyanionic nature: core proteins repel each toher and attract hydration shell: leads to stiffness and cartilage permeability
what collagens make up the primary amount of articular cartilage?**
- primarily type 2!!
a lot of minor types too - fibrocartilage at menisci, transition zone
T/F: articular cartilage damaged doesn’t heal well
true, get fibrocartilage replacement bc cartilage is hypocellular and avascular
what is the function of proteoglycans in articular cartilage?
- other major component of matrix
- combination of protein and glycosaminoglycan
joint innervation
- none in articular cartilage
but there is in the capsule, ligaments, muscle, and subchondral bone
what is the main source of pain in the joint capsule?
outer fibrous layer
what part of the joint capsule is responsible for producing synovial fluid?
inner synovial membrane
inner synovial membrane of joint capsule
- lines inside of joint capsule
- essentially a modified CT
- numerous blood vessels present
- responsible for producing synovial fluid!!
joint capsule arrangement
- outer fibrous layer
- inner synovial membrane
outer fibrous layer of joint capsule
- continuous w periosteum or perichondrium
- made of dense CT
- provides mechanical stability to joint
- more pain sensitive
what are the main functions of synovial lining
- phagocytosis particulate material (move waste products out of joint)
- regulate protein/hyaluronate content
- synovectomy often performed in sx - debated now
kinematics
study of motion of articulating surfaces in relation to each other
kinetics
forces that are created during motion of joint and loads created across articular surface
lubrication
provides frictionless movement of soft tissues and articular cartilages
what are indications for arthroscopy?
- diagnosis
- osteocondral fragments
- intra-articular fractures
- debride OCD/cystic lesions
- synovectomy/lavage for sepsis
what are benefits of arthroscopy?
- less invasive
- visualize more articular surface
what are the goals of arthroscopy?
- view joint structures (cartilage, ligaments, meniscus)
- remove/repair pathology
- stimulate healing: debride, pin etc
- lavage joint (remove debris and inflamm mediators)
why is the incision location for arthroscopy so important?
- avoid muscles, tendons, ligaments
- avoid damage to articular cartilage (blunt trocar)
what are arthroscopy indications?
- osteochondral fragmentation
- fetlock arthroscopy
- intra-articular slab fracture repair (reattach usually)
what is transcondylar screw technique?
- often as a last resort after all other things have been done
- gives good relief tho
- newer lately
how do you close arthroscopy?**
- skin only
- simple interrupted or cruciate pattern
when is arthrotomy indicated?***
- large intra-articular fragments
- large intra-articular fracture
- sepsis
not able to achieve distension needed for arthroscopy
how do you close arthrotomy?***
- synovial layer: small diameter absorbable suture
- simple continuous pattern
- REAPPOSE ANY MAJOR SUPPORTING STRUCTURES, SUCH AS LIGAMENTS THAT HAVE BEEN INCISED: large diameter absorbable or non-absorbable suture, simple interrupted or vertical mattress
- skin: interrupted or continuous depending on location
what is arthrodesis?
- assisted fusion of joint
- indicated when joint destruction is beyond other treatments
- internal fixation for high motion joints (carpus, fetlock, pastern)
- can also do facilitated ankylosis (environment where it will fuse faster)
diagnostic evaluation of joint disease should include
- history
- musculoskeletal palpation
- radiography
what are surgical options for joints?
- arthroscopy
- arthrotomy
