A patella fracture is a break in the kneecap bone. It usually occurs from a fall onto the kneecap or an eccentric contraction of the quadriceps muscle that pulls the kneecap too forcefully. Treatment depends on the type of fracture and ability to perform a straight leg raise test. Non-displaced fractures in patients able to do the straight leg raise can be treated with immobilization, while displaced fractures or inability to do the straight leg raise may require surgery to realign the fragments. Rehabilitation focuses on regaining motion while keeping the knee straight to allow initial healing.

1. Patella Fracture
What is a patella fracture?
A fracture of the patella is an injury to the kneecap. The kneecap bone is one of three bones that make up the knee
joint. The patella is lined with cartilage on its undersurface, and is important in providing strength of extension of the
knee joint.
How does a patella fracture occur?
A patella fracture most often occurs from a fall onto the kneecap. When this occurs, the fracture can be associated
with abrasions and lacerations to the skin overlying the injury. Patella fractures can also occur when the quadriceps
muscle is contracting but the knee joint is straightening (a so-called 'eccentric contraction'). When the muscle pulls in
this manner, the patella can fracture.
What is the treatment of a patella fracture?
When a patella fracture occurs, the patient should be seen in the emergency room.
X-rays will be obtained to determine the type of fracture and the amount of displacement of the fracture. One of the
critical factors in determining the treatment of a patella fracture is the examination of the patient. Specifically, it should
be determined if the patient can perform a straight leg raise.
o Straight Leg Raise
A straight leg raise test is done by having the patient lie flat on a bed. With the leg straight, the patient should then
raise their foot off the bed and hold it in the air. This tests the function of the the quadriceps muscle and its
attachment to the shin bone. A disruption of the quadriceps tendon, patella, or patellar tendon can lead to inability to
perform a straight leg raise.
If a straight leg raise can be done, then non-operative treatment may be possible in the setting of a patella fracture.
Patients with a large hematoma (swollen knee) may benefit from draining the hematoma for pain relief. Immobilizing
the knee with a knee brace will also help minimize discomfort.
When is surgery necessary for a patella fracture?
Patients with nondisplaced, or minimally displaced, fractures who can perform a straight leg raise (as described
above) can usually be treated without surgery. A long leg cast or a knee immobilizer can be used for treatment of
these types of patellar fractures.
When surgery is necessary, an incision is made over the front of the knee joint. The fractured ends are realigned and
held in place with some combination of pins, screws, and wires. In some cases, a portion of the patella can simply be
removed, but this is usually done for smaller fracture fragments.
What is the rehabilitation following a patella fracture?
Following a patella fracture, patients will need to keep their knee in a straight position to allow for initial healing.
Exactly when the knee can begin moving depends on the strength of the repair your surgeon is able to achieve.
Gentle motion can usually begin in the first weeks following surgery.
The most common complication of surgery for a patella fracture is that the metal implants can be painful over time--
especially when kneeling. Because of this, it is not uncommon for a second procedure to remove the metal implants
to be performed. This procedure is usually done at least a year after the initial surgery. Other possible complications
include:
o Infection
o Non healing fractures
o Failure of the fixation to hold the fragments in place
o Kneecap pain (chondromalacia)
o Knee arthritis