Arthrofibrosis Knee: Causes, Symptoms and Treatment

An orthopedic doctor examining patient's knee.

Arthrofibrosis is a joint condition that can affect any major joint like the shoulder, hip or ankle, but it is most common in the knee joint. Arthrofibrosis knee complications usually occur after injury or surgery to the joint, due to the healing process. Arthrofibrosis can be a painful and debilitating condition that requires medical treatment for relief. Here is what you should know about arthrofibrosis in the knee, including the causes, symptoms and treatment.

Causes of Arthrofibrosis Knee Complications

Arthrofibrosis occurs when too much fibrous scar tissue is created when a joint is healing from an injury or surgery. Most arthrofibrosis knee complications occur after a knee surgery, with the most common being anterior cruciate ligament (ACL) reconstruction surgery and total knee arthroplasty (TKA). As the tissue is healing, the body produces too much scar tissue. The reason why this occurs is not known, but it is theorized that it occurs when there is a disruption in the repair or healing, causing the body to continue making scar tissue.

Scar tissue is more fibrous and tough than regular tissue found in the joints. It is not as flexible, restricting the movement of the joint. Most of the symptoms of arthrofibrosis of the knee are caused by the restriction of the joint and irritation of the tissue. The dense scar tissue can impact the muscles, tendons and ligaments, causing them to become shorter and harder with time. If allowed to progress, arthrofibrosis can restrict the knee cap, quadriceps, ligaments and other components in the knee joint.

Symptoms of Knee Arthrofibrosis

The symptoms of arthrofibrosis of the knee can begin as early as a few weeks after the injury or surgery. As the body begins producing too much scar tissue in the knee, there is restriction in range of motion (ROM) and other symptoms. The symptoms of knee arthrofibrosis worsen over time and can become disabling. Some of the symptoms include:

  • Pain in the joint
  • Knee stiffness
  • Limited range of motion
  • Knee joint is warm to the touch
  • Swelling
  • Inability to straighten or bend leg completely
  • Grinding or sensation in the knee with movement

The first symptoms in the early weeks can alert patients and doctors to the possibility of an arthrofibrosis knee complication. At 2-3 weeks post-surgery or injury, the knee should have regained some of its range of motion. If the knee is warm with increased pain, loss of ROM and swelling, it may be experiencing the early stages of arthrofibrosis. Diagnosis in the earliest stages can allow for treatment to reduce the risk of the condition progressing. A physical examination of the ROM of the knee and an MRI may be used for diagnosis.

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Knee Arthrofibrosis Treatment

Beginning treatment in the early stages of arthrofibrosis knee complications offers the best chance of recovery. If signs of arthrofibrosis are present in the 2-3 weeks after ACL or TKA surgery, patients should be monitored. Arthrofibrosis can be diagnosed six or more weeks after the surgery or injury, and treatment can be recommended. In the earliest stages, physical therapy, exercises and night splints may be recommended. This can help reduce adhesions in the muscles and knee joint that can result in more restriction and loss of ROM.

When conservative treatment in the early stages of arthrofibrosis are not effective, surgery may be required. Both debridement of the knee joint to remove scar tissue and manipulation under anesthesia are possible surgical treatments. The surgery can include one or both methods and is followed by continued physical therapy to regain range of motion.

Prevention of Knee Arthrofibrosis

While the exact cause of arthrofibrosis is not known, it once was more common after knee surgery due to the post-surgical recovery procedures. Restricting knee movement after ACL surgery to allow the ligament to heal increased the risk of arthrofibrosis. The protocol now for post-surgery ACL and TKA is to begin moving the joint within hours of the surgery, in most cases. This keeps the joint mobile and reduces the risk of arthrofibrosis. However, the right balance of movement with rest is necessary – aggressive PT can increase risks.

Orthopedic doctors and surgeons are experienced with arthrofibrosis knee complications and can recommend the best prevention methods. Patients recovering from a knee surgery or injury should closely follow the recommended physical therapy and recovery protocols that can help prevent excess scar tissue from forming.
A sportswoman suffering from knee pain and stiffness.
There are an estimated three million patients that experience arthrofibrosis each year, with many cases involving the knee joint. If you have a knee injury to the ligaments or undergo knee surgery, it is important to know the risk of arthrofibrosis knee complications, symptoms and treatment options. Talk to your doctor or orthopedic knee specialist about the risk of arthrofibrosis of the knee and what you can do to prevent this restrictive, painful knee condition.