Fractures: Patella Flashcards
What is the patella?
Sesamoid bone which develops in the quadriceps tendon
Functions of the patella?
Protects knee from physical traum
Increases efficiency of knee extension
Where does the patella articulate with the femur?
Patellofemoral joint
What may disruption to the patellofemoral joint cause?
Secondary osteoarthritis (down the line)
How can the patella be fractured?
Direct - trauma/direct blow to front of knee (causes undisplaced crack or comminuted fracture, INTACT extensor function)
Indirect - quadriceps contracts forcefully (causes transverse patellar fracture, ?DISRUPTED extensor function)
Clinical features of a patellar #?
Swelling
Bruising
Pain + tender
Maybe a palpable gap
Possibly open wounds
How to test if extensor mechanism is intact in a suspected patellar #?
If pt can straight leg raise
Might be difficult bc of pain, lie pt on side if needed
Ix for suspected patellar #?
Plain films (min. 2 views, AP and lateral usually)
Skyline views if diagnostic doubt
Mx of patellar #?
Undisplaced: non-operative - immobilise with hinged knee brace for 6 wks, fully WB
Displaced and/or lost extensor function: operative - either tension band wires, inter-fragmentary screws or cerclage wires. THEN same as undisplaced.
When is arthroscopy used in patellar injuries?
Recurrent patella dislocation and meniscal/ligamentous damage
When is ORIF used in patellar injuries?
Failure of extensor mechanism, open fractures or fracture displacement
When is partial patellectomy used in patellar injuries?
Large comminuted patellar # when ORIF not possible
Partial to preserve as much of patella as possible
