Arthrocentesis General Info Flashcards
risk factors for joint contamination during arthrocentesis (2)
-larger needles/spinal needles (that’s why you should only use a 20 G 1” if possible) -reuse of needles (only use one needle/attempt!)
when doing arthrocentesis in equines you should almost always use a 20 G 1” needle. what are the three exceptions?
-lavaging: need larger!! -bursa: use spinal needle -femoropatellar joint: -cranial approach use 3” spinal needle -lateral approach use 20 G 1.5” needle
reasons for doing arthrocentesis
-diagnostic (lameness evaluation, clin path of joint fluid, contrast studies, to check if joint is involved in wound) -therapeutic (lavage and medications)
tips for arthrocentesis (10)
-remove needle and syringe as one unit -physical restraint is preferred over sedation for diagnostic arthrocentesis -MUST be aseptic -must remove all scrub from skin (can scald) -place needle rapidly WITHOUT syringe -if not fluid initially, try spinning needle -use new needle for every attempt -clipping does NOT affect asepsis; only clip for spinal needles -aspirate or allow some fluid to drip out prior to injection (decreases contamination) -inject local anesthetics (lidocaine) or amikacin following every tap (antimicrobial effects)
where to do a arthrocentesis of the lateral femorotibial joint
proximal to tibia between lateral patellar ligament and lateral femorotibial ligament
what equipment do you need for arthrocentesis (5)
-scrub -clippers (only for spinal needles) -20 G 1” needle or spinal needle (usually only for bursa) -3 cc syringe -lidocaine or amikacin for inside joint afterwards
landmarks for tarsometatarsal joint arthrocentesis
-proximal to head of 4th metatarsal/lateral splint bone: inject dorsomedial at slightly distal angle
landmarks for intercarpal joint arthrocentesis
- radiocarpal bone
- third carpal bone
landmarks for tibiotarsal joint arthrocentesis
- craniodistal to medial malleolus of tibia
- medial or lateral to medial saphenous v.
approaches to arthrocentesis of the medial femorotibial joint
-proximal to tibia between medial patellar ligament and medial femorotibial ligament -using sartorius m. as landmark: insert needle cranial -> caudal parallel to ground between medial patellar ligament + sartorius m.
should you clip prior to arthrocentesis?
ONLY when using spinal needles; does not affect asepsis for regular needles
methods for arthrocentesis of distal interphalangeal/coffin joint
**done while weight bearing -dorsal parallel approach -dorsal incline approach -dorsal perpendicular
does the femoropatellar joint communicate with the other stilfe joints in the equine?
communicates with medial femorotibial joint in 60-65% communicates with lateral femorotibial joint in 1-25% must block all three to block entire stifle in horse!!
largest compartment of the equine stifle
femoropatellar joint
approaches used for arthrocentesis of the metacarpo/metatarsophalangeal joints
- proximal palmar/plantar pouch (back side of joint)
- through collateral sesmoidean ligament
what landmarks do you use when doing an arthrocentesis of the metacarpo/metatarsophalangeal joints using the collateral sesmoidean ligament approach (3)
- dorsal border of M4
- dorsal border of suspensory ligament
- proximal lateral border of sesamoid bone
landmarks for radiocarpal joint arthrocentesis
- distal MEDIAL edge of radius
- radiocarpal bone
dorsal incline approach is used for arthrocentesis of which joint? and how is it done?
distal interphalangeal/coffin joint insert on midline of dorsal foot just proximal to coronary band at an angle perpendicular to the skin
approaches to arthrocentesis of the femoropatellar joint
- cranial using a 3” spinal needle
- lateral using a 20 G 1.5” needle
weight should be rocked forward onto toe/limb unloaded for which arthrocentesis?
lateral approach to arthrocentesis of the femoropatellar joint
how to do arthrocentesis of the metacarpo/metatarsophalangeal joints using the collateral sesmoidean ligament approach
- support joint in flexed position (this pulls the bones up and away from the joint space)
- palpate palmar M3 on lateral side
- inject where the following meet:
- dorsal border of M4
- dorsal border of suspensory ligament
- proximal lateral border of sesamoid bone
landmarks for the cranial approach to arthrocentesis of the femoropatellar joint
between medial and middle patellar ligaments or lateral and middle patellar ligaments into the trochlear groove at a proximally directed angle
landmarks for lateral approach to arthrocentesis of the femoropatellar joint
caudal to lateral patellar ligament + 6 cm proximal to lateral tibial condyle weight should be rocked forward onto toe/limb unloaded
what’s unique about arthrocentesis of stifle?
there are three joint spaces. all must be blocked if you want to block entire stifle
