Scaphoid Frac

Question 1

Location

Answer 1

Waist 65%
Proximal third 25%
Distal third 10%, but most comm in kids

Question 2

Mechanism of inj

Answer 2

Most comm axial load across hyperext and radially deviated wrist. Eg contact sports.

Question 3

Prog

Answer 3

Proximal 5th AVN 100%

Proximal third 33%

Question 4

BS

Answer 4

Major is dorsal carpal br of radial A, enters dorsal surf and supplies proximal 80% of scaphoid via retrograde flow.
Minor supply from superfic palmar arch of volar radial A, enters distal tubercle and supplies distal 20%.

Question 5

movem

Answer 5

Flexes with wrist flexion and radial deviation.

Extends dur wrist ext and ulnar dev.

Question 6

OE

Answer 6

Anat snuffbox tend dorsally. Btw EPL/APL and EPB. Cephalic V in roof. Contents radial A and superfic br radial N.
Scaphoid tubercle tend volarly
Pain with resisted pronation
Push telescoping

Question 7

Scaphoid view XR

Answer 7

30 deg wrist ext
20 deg ulnar dev
Cant see frac til 3 wk somet due to crushed cancellous bone.

Question 8

Mx

Answer 8

Thumb spica cast immob if stable non displ ie under 1mm. Cast for 3 mtnh if distal third, 4 if waist, 5 if proximal.
If under 1mm displ then 90% union rate.
If over 1mm then 50% so ORIF. Also ORIF if frac proximal pole, hump back, perilunate disloc, comminuted, unstable oblique or vertical.
Op- ORIF vs percut crew fixat if unstable and displ.

Question 9

complics

Answer 9

Non union, reqs bone grafts
Scaphoid nonunion advanced collapse.
AVN causes func disabil. 
Arthritis
Carpal instabil