Arthrofibrosis, also known as stiffness or loss of motion, is a frequent complication following knee ligament injury and reconstruction surgery. It involves the proliferation of scar tissue within and around the knee joint. Arthrofibrosis impairs knee extension and flexion, and can be severely disabling. Reported incidence following ACL reconstruction ranges from 4-35%.

The acute inflammatory response triggered by ligament injury induces fibroblast proliferation and excessive collagen deposition.2 This scar tissue contracts and entraps the knee, preventing normal range of motion. Histopathology reveals metaplasia, cartilage formation, and endochondral ossification within the arthrofibrotic tissue.3 Risk factors include early ligament reconstruction, concomitant procedures, improper graft placement, and prolonged immobilization.

The primary symptom is progressive loss of knee extension and/or flexion. Patients report stiffness, pain with terminal motion, and difficulty with activities. Physical exam reveals firm endpoint on range of motion testing. Radiographs may show loss of joint space and osteophytes. MRI reveals diffuse capsular thickening and scarring.4

Initial treatment centers on physical therapy for range of motion and strengthening. Oral anti-inflammatories, bracing, and steroid injections can also be attempted. Patients who fail conservative management undergo surgical arthroscopic and/or open lysis of adhesions and scar tissue, followed by aggressive therapy.5 Outcomes are generally good for mild cases, but more extensive involvement often results in residual deficits.

Strategies for preventing arthrofibrosis include delaying ligament surgery until acute inflammation has resolved, proper graft placement, avoiding excessive graft tension, early knee motion and quadriceps strengthening, use of anti-inflammatories, and watchful monitoring for signs of stiffness.6 If detected early, recurrence can often be avoided with prompt intervention.

Arthrofibrosis poses a challenging complication after knee ligament surgery. Close monitoring and early range of motion are key to prevention. Surgical lysis techniques can improve severe stiffness that fails conservative measures. Residual deficits remain common, emphasizing the importance of prevention. Further research is needed to define optimal treatment algorithms.

1. Millett PJ, Williams RJ 3rd, Wickiewicz TL. Open debridement and soft tissue release as a salvage procedure for the severely arthrofibrotic knee. Am J Sports Med. 1999;27(5):552-561.

2. Harner CD, Irrgang JJ, Paul J, Dearwater S, Fu FH. Loss of motion after anterior cruciate ligament reconstruction. Am J Sports Med. 1992;20(5):499-506.

3. Sebastianelli WJ, Gillespie MJ, Hicks DG, DeHaven KE, Cosgarea AJ. The histopathology of arthrofibrosis following ACL reconstruction. Arthroscopy. 1993;9(4):359-360.

4. Williams RJ 3rd, Laurencin CT, Warren RF, Speciale AC, Brause BD, O’Brien S. Septic arthritis after arthroscopic anterior cruciate ligament reconstruction: diagnosis and management. Am J Sports Med. 1997;25(2):261-267.

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

6. Beynnon BD, Johnson RJ. Anterior cruciate ligament injury rehabilitation in athletes. Biomechanical considerations. Sports Med. 1996;22(1):54-64.