Reviewed and Approved by Dr Ritwik Kejriwal (Orthopaedic Surgeon)
A return to theatre after ACL reconstruction can feel like a setback, but it is not uncommon and does not necessarily mean the ACL graft has failed.
Large series report reoperation rates of around 15–20% within the first few years after ACL reconstruction. Common reasons include meniscal procedures, cyclops/scar tissue removal, hardware removal and graft-related problems. In one large Scandinavian series, 16.9% of patients underwent another procedure within two years.
In my own practice, approximately 7% of ACL reconstruction patients require a further procedure. Most common issues include residual scar tissue, stiffness, a cyclops-type lesion, or a symptomatic chondral/cartilage flap that is limiting rehabilitation.
Think of it as a final adjustment
For some patients, the ACL graft is stable and progressing well, but one remaining mechanical issue is holding the knee back.
In that situation, a small arthroscopic procedure can sometimes be thought of as a final adjustment or tidy-up: removing scar tissue, restoring free movement, or addressing symptomatic cartilage pathology so rehabilitation can progress again.
The aim is not to “redo” the ACL. It is to remove the obstacle that is preventing the knee from becoming calm, mobile and strong.
Timing
In my practice, these patients often come back for reassessment between 6 and 12 months after ACL reconstruction, although this is not a rigid timeline.
I would consider re-assessment when there is:
Plateauing of range of motion, especially persistent extension loss
Recurrent effusion despite sensible load modification
Mechanical symptoms, such as catching, clunking or a sense of obstruction
Overall lack of rehabilitation progression despite good engagement and a structured programme
A patient who is steadily improving usually needs more rehabilitation. A patient who has clearly plateaued for several months deserves another look.
Early recognition still matters
Arthrofibrosis is usually managed stepwise, and many patients improve without another operation. When surgery is required, arthroscopic lysis of adhesions generally improves range of motion; one systematic review also found better results when treatment was undertaken within eight months in one included study.
Interestingly, emerging research suggests that the biological response associated with postoperative stiffness may not be entirely negative. Recent ISAKOS data found very high meniscal healing rates in patients who developed arthrofibrosis after meniscal repair, almost all of whom also had cruciate ligament reconstruction. The authors suggested that an over-active inflammatory response may potentially favour tissue healing, although this remains hypothesis-generating rather than proven.
Practical takeaway
Progressing → continue rehabilitation
Plateauing → reassess the programme
Persistent swelling, mechanical symptoms or stalled ROM → re-refer
A repeat procedure after ACL reconstruction is not automatically a failure. In selected patients, it can be the final adjustment that allows rehabilitation to move forward again.
References
Lord L, Cristiani R, Edman G, Forssblad M, Stålman A. One sixth of primary anterior cruciate ligament reconstructions may undergo reoperation due to complications or new injuries within 2 years. Knee Surg Sports Traumatol Arthrosc. 2020.
Ekhtiari S, Horner NS, de Sa D, et al. Arthrofibrosis after ACL reconstruction is best treated in a step-wise approach with early recognition and intervention: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2017.
Chen L, Gosnell GG, Esser KL, et al. Impact of Arthrofibrosis on Meniscal Healing and Retear Rates Following Surgical Repair. ISAKOS Congress 2025.