arthrocentesis

Question 1

4 indications for arthrocentesis

Answer 1

-acute closed lock
-previous surgery w/ continued discomfort
-TMJ arthralgia
-Wilkes classification 1,2,3

Question 2

3 contraindications for arthrocentesis

Answer 2

-ankylosis
-overlying skin infection
-inability to appreciate anatomy (obesity)

Question 3

what is the canthal tragal line called and where are the points?

Answer 3

aka Holmlund-Hellsing line
10 mm and 2 mm below
20 mm and 10 mm

Question 4

first point in holmlund hellsing line

Answer 4

deepest point in glenoid fossa

Question 5

2nd point of holmhund hellsig line

Answer 5

height of the articular eminence

Question 6

steps to arthrocentesis

Answer 6

1.marking pen to draw out canthal tragal line
2.prepare skin with antiseptic
3.use local anesthesia w/o epi
4.manipulate jaw to open space
5.insufflate superior disk space with 27 gauge needle
6. using 18 gauge needle aim needle at 45 degree angle superiorly and anteriorly to reach lateral aspect of zygomatic arch, then walk off bone to enter superior joint space (anterior port)
7. place posterior port
8.irrigate with LR at least 100 ml
9. remove anterior port and inject single agent vs steroid combo
10.manipulate joint and check opening under sedation
11. post op management; aggressive range of motion exercises, NSAIDS,splints

Question 7

avg superior joint space is how large

Answer 7

3 cc

Question 8

what can lavaging the joint do?

Answer 8

-break up adhesions which can allow the disk to recapture into its premorbid position.
-irrigates out inflammatory mediators

Question 9

what can you inject into the joint via posterior port

Answer 9

-kenalog 40 mg/ml
-hyaluronic acid 10 mg/ml
-local anesthesia bupivacaine 0.5% w/ 1:200 epi
-morphine 10 mg/ml

Question 10

indications for disk reposition procedure, surgical position to manually reposition the disk into its premorbid position

Answer 10

-failure of conservative therapy
-Wilkes 2-5