Management of ACL Injuries


Optimal management of ACL injuries remains controversial. While early reconstruction may reduce instability and secondary injury risk, some patients cope successfully without surgery. Defining indications for reconstruction versus conservative treatment is an important research priority.

Risk Stratification

A prospective cohort study stratified 209 patients into high, moderate and low risk groups based on initial knee laxity and preinjury activity level.1 Early reconstruction was recommended for high-risk patients and conservative treatment for low-risk patients. Moderate-risk patients were quasi-randomized to early reconstruction or conservative treatment based on clinic day.


The moderate- and high-risk groups had similar rates of late reconstruction or meniscal surgery, significantly higher than the low-risk group. Early reconstruction reduced late meniscal surgery and symptomatic instability compared to conservative treatment across all risk levels. However, activity scores remained below preinjury levels in both groups at 5+ year follow-up. Early reconstruction also increased mild degenerative changes on radiographs.


This study provides reasonable guidance for ACL treatment based on easily measured risk factors. High-risk patients clearly benefit from early stabilization. Low-risk patients have lower rates of late surgery with conservative treatment. Moderate-risk patients should be counseled on tradeoffs of early reconstruction versus activity modification and secondary injury risk with conservative care.

Other Evidence

A systematic review found insufficient evidence from 5 trials to determine if reconstruction is superior to conservative treatment.2 Pooling of data was limited by heterogeneity. A registry study of over 6500 ACL injuries found early reconstruction significantly reduced ipsilateral re-injury risk.3 Further high-quality randomized trials are still needed to clarify optimal treatment strategies.


Patient-specific factors including activity level, occupation, and willingness to modify activities should help guide shared decision-making for ACL management. Early reconstruction may reduce late surgical needs, but risks and benefits are unclear for lower demand patients. Limitations persist in current evidence.


1. Fithian DC, Paxton EW, Stone ML, et al. Prospective trial of a treatment algorithm for the management of the anterior cruciate ligament-injured knee. Am J Sports Med. 2005;33(3):335-346.

2. Linko E, Harilainen A, Malmivaara A, Seitsalo S. Surgical versus conservative interventions for anterior cruciate ligament ruptures in adults. Cochrane Database Syst Rev. 2005;(2):CD001356.

3. Dunn WR, Lyman S, Marx RG. The effect of ACL reconstruction on the risk of knee re-injury: an outcome study of 6,576 cases. Paper presented at: American Orthopaedic Society for Sports Medicine Annual Meeting; July 20-23, 2003; San Diego, CA.

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© 2023 Dr. Robert Afra – San Diego Orthopedic Surgery Shoulder – Knee – Elbow