How many bones are there in the knee?
There are four major bones in the knee, including:
- the femur
- the tibia
- the fibula
- the patella
But did you know about the fabella! The fabella is a tiny bone that sits in the back of the knee in about 10-30% of humans. It’s usually embedded in the gastrocnemius muscle and you wouldn’t even know it’s there until you got an x-ray!
What are the ligaments that support the knee?
This is an easy question with a complex answer! If you consider all structures that are considered ‘ligaments’ in some context, there are 13. They include:
Extracapsular ligaments (those outside the joint capsule)
- medial retinaculum
- lateral retinaculum
- patellar ligament
- lateral collateral ligament
- medial collateral ligament
- oblique popliteal ligament
- arcuate popliteal ligament
Intracapsular ligaments (those inside the joint capsule)
- anterior cruciate ligament
- posterior cruciate ligament
- anterior meniscofemoral ligament (Ligament of Humphrey)
- posterior meniscofemoral ligament (Ligament of Wrisberg)
- transverse ligament
- meniscotibial ligaments (coronary ligaments)
Why does my knee hurt when I go downstairs but not upstairs?
Pain at the front of the knee is often due to abnormal forces passing through the kneecap joint, and biomechanical studies show us why sometimes we experience pain down, but not up, stairs. Compared to normal walking and walking up stairs, down stairs puts the most load through the kneecap joint and is therefore more likely to be a problem.
- Walking – 261% of body weight
- Up stairs – 316% of body weight
- Down stairs – up to 346% of body weight