Arthrofibrosis is a condition where excessive scar tissue forms within a joint, leading to pain, stiffness, and a significant loss of motion. This abnormal healing response can happen in any joint but is most frequently observed in the knee, shoulder, hip, and elbow. While scar tissue is a normal part of healing, in arthrofibrosis, its production becomes excessive and disorganized, restricting the joint’s natural movement.
Causes and Risk Factors
The development of arthrofibrosis is primarily triggered by significant trauma to a joint or as a complication following joint surgery. Procedures like anterior cruciate ligament (ACL) reconstruction and total knee arthroplasty (TKA) are frequently associated with this condition. The body’s inflammatory response to such events can become dysregulated, leading to the overproduction of fibrous scar tissue.
Certain factors can increase an individual’s susceptibility to this condition. Prolonged immobilization of a joint after injury or surgery is a significant risk factor, as lack of movement can encourage scar tissue to become dense and restrictive. Post-operative infections can also disrupt the normal healing process, promoting excessive scarring. There is also evidence of a genetic predisposition in some individuals. Improper placement or sizing of a graft during ACL surgery can also contribute to the problem.
Symptoms and Diagnosis
The most prominent symptom of arthrofibrosis is a progressive loss of the joint’s range of motion, which feels like a hard, mechanical block rather than simple muscle tightness. This stiffness is accompanied by persistent pain, chronic swelling, and a feeling of warmth around the joint. Patients may find it increasingly difficult to perform daily activities, such as fully straightening their leg, which can result in a limp. Some individuals may also experience a grating sound or sensation, known as crepitus, during movement.
Diagnosing arthrofibrosis begins with a physical examination where a clinician measures the joint’s active and passive range of motion to quantify the restriction. A detailed patient history is also taken to understand any previous injuries or surgeries. To confirm the diagnosis and rule out other issues like bone fragments or cartilage damage, imaging studies are required. An MRI is particularly useful as it provides a detailed view of the soft tissues, showing the extent and location of the scar tissue.
Non-Surgical Treatment Approaches
The initial treatment for arthrofibrosis is conservative and focuses on restoring motion without surgery. Physical therapy is the main component of this approach and is often highly specific and aggressive. The goal is to remodel the scar tissue and stretch the tightened joint capsule. Therapists employ techniques such as low-load, long-duration stretching, holding the joint in a gentle, prolonged stretch to lengthen fibrous adhesions.
This intensive therapy is designed to mechanically break down excessive scar tissue and restore flexibility. Special devices may be prescribed for home use to help patients apply these stretching protocols. The focus is on first restoring full extension (the ability to straighten the joint) before working on flexion (bending). For many with milder forms of arthrofibrosis, a dedicated physical therapy regimen can decrease pain and improve function enough to avoid surgery.
When physical therapy alone is not sufficient, a procedure known as Manipulation Under Anesthesia (MUA) may be performed. During an MUA, the patient is placed under anesthesia, and the surgeon forcefully moves the joint through its complete range of motion to manually break up restrictive scar tissue. Because it does not involve any incisions, it is considered a non-invasive procedure, though it is performed in an operating room.
Surgical Interventions
When non-surgical methods fail to restore adequate joint function, surgical intervention may be necessary. The most common procedure is an arthroscopic surgery known as lysis of adhesions or debridement. In this minimally invasive technique, a surgeon makes small incisions to insert a camera to visualize the internal structures. Through other incisions, specialized instruments are used to carefully cut out and remove the excessive scar tissue restricting movement.
The surgeon can precisely target and excise the fibrous bands causing the stiffness, freeing the joint capsule and restoring the space needed for normal mechanics. For severe or recurrent cases of arthrofibrosis, a more traditional open surgery may be required to gain better access and remove a larger volume of scar tissue. Following any surgical intervention, an immediate and intensive course of physical therapy is started. This post-operative rehabilitation helps to prevent the scar tissue from reforming and ensures the restored range of motion is maintained for a successful long-term outcome.