What is knee arthrofibrosis? My twin sister has this as a result of a baseball injury to her ACL.

Arthro refers to any joint. Fibrosis is scar tissue or adhesions. Arthrofibrosis of the knee occurs most often after a knee injury or knee surgery.

It is characterized by a loss of motion called a joint contracture. The extent of the problem is defined by the severity of the contracture. There can be a loss of both knee flexion and extension.

Most people can get along fine with a small loss of flexion. Deep squatting or full kneeling may be a problem. Loss of full extension is much more problematic, especially for the athlete. Even a small amount of extension loss can cause a limp and knee pain.

Arthrofibrosis can be mild to severe. It can range from a local problem in one area of the joint to all compartments of the knee. In more involved cases, even the soft tissues and muscles around the knee can be affected.

Loss of motion with knee arthrofibrosis is the most severe after a high-energy injury that tears or ruptures more than one ligament. Low-energy, single-ligament trauma is usually less severe in its consequences.

Motion is lotion and is the first line of defense to prevent arthrofibrosis after knee injury and/or surgery such as an ACL repair. Surgery may be needed to manipulate the knee and remove the adhesions. The procedure must be done with care to avoid damage to the bone, tendon rupture, or fracture of the patella (knee cap).