Arthrofibrosis after patellar injury or surgery

Scarring around the patella can lock up the whole joint, and it is not uncommon after patellar injury or surgery.

First published in 2011, and reviewed August 2023 by Dr Sheila Strover (Clinical Editor)

Arthrofibrosis is a condition of scarring within and around the knee joint. It may complicate a number of knee conditions, and may end up affecting the mechanics of the kneecap.

One of the main situations where arthrofibrosis was first fully respected was cruciate ligament reconstruction. In the early days of this procedure it was common for the knee to be immobilised for some time after surgery, and a high percentage of patients were finding that they were having great difficulty regaining their full range of motion due to the development of adhesions - and later scarring - within the joint cavity.

Surgeons found that there were two important things to understand after this procedure:

• not to undertake the cruciate surgery until the early inflammation had settled down
• to get the knee moving again as soon as possible after surgery to break down adhesions and prevent the adhesions maturing into scar tissue

Arthrofibrosis affecting the patella is initially the result of adhesions in the suprapatellar pouch - the extension of the joint cavity above the patella - and also the lateral gutters on each side of the joint cavity and the region under the patellar tendon. Flexion (bending) is affected by virtue of the patella being 'stuck down' with the adhesions and scar tissue. Later on the scar tissue under the patellar tendon contracts and can pull the patella downwards into the position known as patella infera (also called patella baja). In this position the patella can impinge on the top of the tibia and cause pain and joint surface damage.

PREVIOUS PART: Key arthrofibrosis resources on the KNEEguru site

NEXT PART: Complex Regional Pain Syndrome (CRPS)