treatment

Last reviewed 01/2018

The aim of treatment is to:

• maintain the function of extensor mechanism
• articular congruity
• full, painless motion of the knee (1)

Treatment depends on the type of fracture.

• if the fracture is undisplaced or only minimally displaced then,
• after any haemarthrosis has been aspirated and the extensor mechanism has been checked to see if it is still intact, it may be treated with a plaster cylinder.
• this is worn for 4-6 weeks
• every day quadriceps exercises should be performed.
• if there is a stellate (comminuted) fracture of the patella then
• the same initial management re: haemarthrosis and checking of knee extension are performed
• small fragments can be removed or repaired with suture or screw fixation
• poor outcomes are seen if more than 40% of the patella is removed, hence every effort should be made to conserve and stabilize as much of the patella as possible  
• patients with massively comminuted fracture may be treated by patellectomy or with a plaster cast.
• although it may reduce the pain related to the fracture, the mechanical advantage provided by the patella to the extensor mechanism is decreased
• loss of quadriceps strength can be seen in as much as 49% of patients who has undergone total patellectomy and may cause inability of climbing stairs or getting out of a chair (1)
• if the fracture is a displaced transverse fracture then
• an operation is required to internally fix the bony fragments - tension band technique  - traditionally two axial Kirschner wires with a figure-of-eight wire anteriorly is used
• plaster backslab is then worn until the extension mechanism of the knee is regained.

Note that in all of these different treatment regimes it is essential to perform daily exercises of flexion and extension of the knee joint.

Reference:

• (1) Scolaro J, Bernstein J, Ahn J. Patellar fractures. Clin Orthop Relat Res. 2011;469(4):1213-5.