Pain at the front of the knee can be caused by patella (knee cap) problems.
The patella can also dislocate and this can happen recurrently.
Pain from the kneecap can be caused by damage to the cartilage on the back of the kneecap or owing to cartilage damage in the groove in which the patella runs (the trochlear groove). This can be caused by injury or can be caused by the kneecap maltracking (not running true) in the trochlear groove. This in turn can be caused by tight structures on the outside of the knee. This condition sometimes responds to physiotherapy but if these do not help it can be improved by surgery – for example an arthroscopy and closed lateral release, where the tight structures causing the maltracking are released.
A recurrently dislocating patella needs careful assessment to determine the cause of the problem. The assessment includes x-rays and scans. The treatment then focuses on dealing with the underlying cause. This may involve physiotherapy or realignment of the patella.