Arthrofibrosis is a frequent complication after anterior cruciate ligament (ACL) reconstruction, characterized by abnormal scar tissue formation leading to loss of knee extension or combined loss of extension and flexion.1 It causes substantial morbidity with pain, stiffness, weakness, and disability. Appropriate classification and treatment of this disabling condition are essential.

A practical classification divides arthrofibrosis into four types based on physical exam:2

– Type 1: <10° extension loss, normal flexion – Type 2: >10° extension loss, normal flexion
– Type 3: >10° extension loss, >25° flexion loss, patellar tightness
– Type 4: >10° extension loss, >30° flexion loss, patella infera

This stratifies severity and guides appropriate treatment. More severe arthrofibrosis often requires more extensive surgical scar resection and postoperative rehabilitation.

All patients initially undergo nonoperative treatment emphasizing physical therapy and range of motion exercises. If this fails, arthroscopic anterior scar resection and debridement are performed, followed by aggressive postoperative extension casting and mobilization.2 Notchplasty and partial graft resection may be necessary for more severe arthrofibrosis. Serial casting and bracing facilitate recovery of full extension before focusing on regaining flexion.

In a series of 72 patients, arthroscopic treatment and structured rehabilitation led to significant gains in extension (7° to 18° depending on severity) and flexion (27° to 28° for Types 3 and 4).2 Patient-reported outcome scores also improved across all arthrofibrosis types. Mild cases generally had better outcomes than more advanced arthrofibrosis. Recognizing and classifying the degree of arthrofibrosis allows appropriate management.

Arthrofibrosis should be prevented through structured perioperative rehabilitation emphasizing early motion. When arthrofibrosis occurs, prompt diagnosis and treatment enable good functional recovery in most patients. Classification guides surgical approach and postoperative protocol. Further research could better define arthrofibrosis risk factors and optimize prevention strategies.

1. Cosgarea AJ, DeHaven KE, Lovelock JE. The surgical treatment of arthrofibrosis of the knee. Am J Sports Med. 1994;22(2):184-191.

2. Shelbourne KD, Patel DV, Martini DJ. Classification and management of arthrofibrosis of the knee after anterior cruciate ligament reconstruction. Am J Sports Med. 1996;24(6):857-862.

3. Mayr HO, Stoehr A, Dietrich M, et al. Graft-tunnel mismatch is a risk factor for anterior cruciate ligament reconstruction failure. Arthroscopy. 2016;32(5):818-824.

4. Sgaglione NA, Del Pizzo W, Fox JM, Friedman MJ. Critical analysis of knee flexion after anterior cruciate ligament reconstruction. Am J Sports Med. 2002;30(5):660-663.