An anterior interval release is a surgical procedure to remove scar tissue in the 'anterior interval' - a region behind the patellar tendon.

anterior interval arthrofibrosis

In patients with arthrofibrosis, the anterior interval behind the patellar tendon may become obliterated with adhesions and scar tissue, and the tissues may stick down to the front of the tibia, together with the tendon.

anterior interval release

Anterior interval release removes the scar tissue in the anterior interval, and frees up the tendon again, allowing an improved range of motion and reducing patellar pain.


Arthroscopic release

Surgery for such scarring is specialist domain, and this procedure should only be carried out by a surgeon experienced in this problem. The release is generally performed via the arthroscope.

arthrolysis of the anterior interval
Q&A-style article all about arthrofibrosis.

Anterior interval arthrofibrosis

A brief look at how the kneecap can become tethered by scarring in the region of the 'anterior interval'.

The anterior interval

An explanation of the very important gap under the patellar tendon

Dr Peter Millett chats about his experience with infrapatellar contracture syndrome and the importance of recognising it early before the shortening of the patellar tendon becomes irreversible.

Dr Peter Millett discusses why knee surgeons need to be aware that arthrofibrotic scarring can occur in this area because of the position of their arthroscopic portals (cuts).

The editor's interpretation of a 2004 article highlighting the important anatomy associated with arthrofibrosis of the knee.




Surgical Technique for Release of Anterior Interval Scarring of the Knee After Anterior Cruciate Ligament Reconstruction. Rose M, McNeilan R, Genuario J and Schlegel T. Arthroscopy Techniques September 2018 Volume 7, Issue 9, Pages e887–e891.

Intraarticular arthrofibrosis of the knee alters patellofemoral contact biomechanics. Mikula JD, Slette EL, Dahl KD, Montgomery SR, Dornan GJ, O’Brien L, Turnbull TL and Hackett TR. J Exp Orthop. 2017 Dec; 4: 40.

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