TTP knee, based on the provided reference, refers to a measurement related to the tibial tubercle prominence (TTP). It's not a diagnosis or condition itself, but rather a way to quantify the anterior prominence of the tibial tubercle relative to the tibial plateau.
In essence, TTP is a measurement used to assess how far forward the tibial tubercle (the bony bump on the front of your shinbone just below the knee) protrudes.
Measuring Tibial Tubercle Prominence (TTP)
According to the provided reference, TTP is defined as:
- The vertical distance from the most prominent point of the tibial tubercle to the perpendicular line of the tangent of the medial tibial plateau passing through the anterosuperior angle of the tibial outline (the same point used for the CD index).
Here's a breakdown to better understand this definition:
- Most prominent point of the tibial tubercle: This is the point on the tibial tubercle that sticks out the furthest.
- Medial tibial plateau: The top surface of the tibia (shinbone) on the inner (medial) side of the knee joint.
- Tangent of the medial tibial plateau: A line that touches the surface of the medial tibial plateau at only one point, without crossing it.
- Anterosuperior angle of the tibial outline: The front and upper corner of the tibial outline, from an X-ray or imaging perspective.
- Perpendicular line: A line at a right angle (90 degrees).
So, in simpler terms, imagine a line drawn along the top of the inner part of your shinbone where it meets the knee. Then, measure the vertical distance from the most prominent point of the tibial tubercle to that line. That distance is the TTP.
Why Measure TTP?
While the reference does not explicitly state why TTP is measured, it's often used in the context of:
- Evaluating patellar tracking: An increased TTP can affect how the patella (kneecap) tracks in the trochlear groove of the femur (thigh bone).
- Assessing risk factors for knee pain and instability: Deviations in TTP can contribute to conditions like patellofemoral pain syndrome (PFPS) or patellar instability.
- Planning surgical interventions: In cases of patellar maltracking or instability, TTP measurement can help guide surgical decisions to realign the patellar tendon.
Example:
Imagine someone has a very prominent tibial tubercle. This would result in a larger TTP measurement, potentially indicating an increased "pull" on the patellar tendon, which could contribute to knee pain or instability.
