In patellar tilt, the patella is situated in the middle of the groove in which it normally rides (the trochlear groove of the femur), but it is tilted over to one side because of tightness of the normal fibrous support there. There is a fibrous support on the inner and outer aspects of the patella (medial and lateral retinaculum), but it is usually the lateral retinaculum that tightens up. For this reason tilt is usually to the outer or lateral side.
Malalignment means that the patella in not central in its underlying groove but is too far over either to the inner (medial) or outer (lateral side). The patella may be pulled over too far to the side (usually lateral) by any of several structures being poorly aligned. For example, if the attachment of the patellar tendon to the tibia bone is in a poor position this may cause the malalignment.
A patella may be both tilted and malaligned. This implies both a local cause (tight lateral retinaculum) associated with a more distant problem, such as a poorly-positioned tibial tubercle.
Patellar maltracking means that the excursion of the patella as the knee bends and straightens is not central, but tends to one or other side. Clearly, the terms malalignment and maltracking are similar, but one really relates to a static position (eg as one might see on an X-ray or during surgery), while the other relates to the situation during movement of the knee.