The anterior interval of the knee is the area between the anterior portion of the tibia (or the front portion of the tibia) and the fat pad (which lies in this area) and area posterior to (or just behind) the patellar tendon.
This area is sometimes called the 'pre-tibial recess' or the 'anterior interval of the knee'.
The patellar tendon changes its angle of takeoff from the tibia as the knee is placed through flexion and extension, and when this area becomes scarred that normal excursion and change in angle does not occur - and that leads to abnormal loading in the patello-femoral joint and can lead to premature arthritis in that area.
When it is treated surgically, it is important for the surgeon to recognise that this is a common area of scarring because the portal location for surgery needs to be positioned so that you can visualise in that area, as it can sometimes be difficult to visualise that area if your portals are not placed appropriately. And then the scar tissue in that area needs to be appropriately resected or released so that the patellar tendon can move in its normal way. It is very important to preserve and not damage the intermeniscal ligament - which is a ligament that runs between the medial and lateral menisci - and it is important not to damage the ACL or to excessively damage or create additional trauma to the fat pad because the fat pad then can become scarred.