Arthrofibrosis after Knee Replacement – Arthroscopic Lysis of Adhesions (Arthroscopic Arthrolysis):
If physical therapy and manipulation under anesthesia (MUA) fail, arthroscopic lysis of adhesions or arthroscopic arthrolysis (arthroscopic removal of scar tissue) is considered.
This procedure is preferably performed between 3 and 6 months after total knee replacement. The results are better if it is done between 3 to 6 months. The effectiveness of arthroscopic arthrolysis progressively declines after 6 months.
In this procedure, the scar tissue from the inside of the knee joint is removed using arthroscopic instruments. As much scar tissue as possible is removed and adhesions are released from all the compartments of the knee joint as follows: Scarred Hoffa fat pad (fat pad behind the tendon of knee cap), scar down to the proximal tibia (area in front of the upper most part of leg bone), patella (knee cap) and peripatellar region (area around the knee cap), suprapatellar pouch (area between the knee cap and quadriceps tendon), intercondylar notch (area in front of the lower most part of thigh bone), medial and lateral retinacula or capsule (soft tissue sleeves on either side of the knee cap), medial and lateral gutters (joint spaces within the knee capsule on the inner and outer sides of the knee joint), residual menisci, pseudomenicus (scar tissue that forms where the original menisci existed) and cyclops lesion (scar tissue that forms in the front compartment of the knee joint). If the posterior cruciate ligament is present and is tight, it could also be released. Lateral release can also be performed as needed. In addition, loose bodies can be removed and soft titssue impingement can be treated. Most of the knee joint mobility is gained after the release of medial and lateral gutters. Release medial and lateral retinacula improve patellar mobility.
Arthroscopic arthrolysis may be helpful in arthrofibrosis involving a portion of the knee joint (localized arthrofibrosis) as well as arthrofibrosis involving the whole knee joint (diffuse arthrofibrosis). But some investigators believe that the use of arthroscopic arthrolysis should be restricted only to localized arthrofibrosis. Removal of all the scar tissue may not be necessary and it can be selective focusing only on scar tissue that is causing symptoms.
Arthroscopic arthrolysis is useful only for removal of scar tissue from the inside of the knee joint (intra-articular fibrosis). It is not helpful in removing scar tissue involving the soft tissue outside the knee joint capsule (extra-articular fibrosis) like scar tissue involving quadriceps (quadriceps fibrosis). Also, it is difficult to reach the areas behind the knee prosthesis (posterior recess) and release posterior capsule with arthroscopic instruments.
Potential complications include prosthetic infection, development of sinus, scratching the prosthetic components and other complications associated with arthroscopic surgery.