Arthroscopy

Question 1

Angle of joint flexion and landmarks for dorsal middle carpal ASY

Answer 1

Limb in approx 70° flexion

Camera portal is typically dorsolateral (pathology is medial so need medial instrument portal) halfway between ECR and CDE tendons (skin incisions made before distension) and halfway between distal and proximal rows of carpl bones.

Question 2

Which joint has been positioned for ASY

Answer 2

Dorsal approach to MCj

70deg flexion

Question 3

Limb position for dorsal ABCj ASY and portal sites

Answer 3

Limb in 120-130° flexion (ie much less flexed than for MCj

Standard lateral portal is halfway between ECR and CDET and halfway between distal radius and proximal row

Medial portal is medial to ECR, at the center of a triangle formed by the extensor carpi radialis, the distal rim of the radius, and the dorsal rim of the radial carpal bone. The joint narrows at this point so care re iatrogenic damage on insertion

Question 4

Limb position for palmar ASY of ABCj and portal sites - palmaromedial

Answer 4

Limb positioned with very slight (20-30degrees) carpal flexion

Palmaromedial portal is palmar to the medial collateral ligament at the level of the distal radius, dorsal to the tendon of insertion of flexor carpi radialis and medial palmar vein

Note that passage from lateral to medial in the palmar carpal joints isnt possibe dt tight attachment of joint capsule and palmar carpal ligament to C3. Therefore have to leave sufficient space for an adjacent instrument portal if required (eg palmaromedial RCB fractures)

Question 6

Limb position for palmar ACBj - palmarolateral portal

Answer 6

Limb in 20-30 degrees (slight) flexion

Palmarolateral approach is more complex as 3 outpouchings are present around the ACB - The proximal outpouching between the caudal radius and proximal margin of ACB is larger and provides clinically useful access to the accessoriocarpal radial articulation

Portal is placed at the most proximal area of the distended outpouching

Question 7

Limb position for palmar MCJ ASY and lateral and medial portal sites

Answer 7

Less commonly indicated than ABC

Slight 20-30degrees of flexion - as for palmar ABC

Portals generally made at the centre of the distended outpouchings

Medial portal is located between radial and second carpal bones palmar to MCL

Lateral portal is is between the ulnar and fourth carpal bones palmar to the LCL and between the accessoriocarpal ulnar and accessoriocarpal quartal ligaments (as for blocking). Lateral capsule is thinner and joint more voluminous vs medial