The trochlear groove is the concave surface where the patella (kneecap) makes contact with the femur (thighbone). Also called the 'trochlea'.


Congruity of patella and trochlear groove

The walls of the trochlear groove would normally contain the patella as the knee bends and straightens. Sometimes the groove is abnormal - trochlear dysplasia - and this may result in patellar instability.

trochlear groove patella in trochlear groove The upper part of the trochlear groove is flatter, and the patella is more easily able to ride over the walls of the groove when the knee is in extension (straight).

Explaining how the kneecap glides within the underlying groove of the femur bone.

Knee bones from above

Simple illustrations to give a birds' eye view of the knee bones.

Patellar instability and dislocation

Discussing how the anatomy can affect the tendency to dislocate the patella.



The sulcus line of the trochlear groove is more accurate than Whiteside’s Line in determining femoral component rotation. Talbot S, Dimitriou P, Radic R, Zordan R and Bartlett J. Knee Surg Sports Traumatol Arthrosc. 2015; 23(11): 3306–3316.

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