patella fracture ]

Question 1

what is the patella

Answer 1

sesamoid bone that develops in quads tendon
* protects knee
* involved in extension - increases distance of quads from centre of knee

Question 2

complication of damage to posterior of patella

Answer 2

OA

Question 3

impact of direct injury to patella - eg dashboard

Answer 3

undisplaced crack / comminuted fracture
intact extensor mechanism

Question 4

how is there indirect injury to the patella

Answer 4

quads forcefully contract against a block to knee extension
eg:
when someone catches their foot against a solid obstacle and in order to prevent themselves from falling the quadriceps contracts forcefully.

Question 5

injury from indirect patella fracture

Answer 5

transverse fracture
possible disruption of extension system

Question 6

clinical features of patella fracture

Answer 6

swelling and bruising
pain and tenderness
palpable gap
if can straight leg raise - extensor mechanism is grossly in tact - lie on side to eliminate gravity

Question 7

ix for patella fracture

Answer 7

plain XR - minimum 2 views - AP and lateral

Question 8

mx of patella fracture

Answer 8

Undisplaced fractures, particularly vertical fractures with an intact extensor mechanism
* non-operatively in a hinged knee brace for 6 week
* fully weight bear.

displaced / loss of extensor mech
* operative - tension band wire, interfragmentary screws, cerclage wires
* hinged brace 4-6wks
* fully wht bear