Twenty-Year Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Prospectively Collected Data

Abstract

Background:

Several long-term (≥20 years) follow-up studies after anterior cruciate ligament (ACL) reconstruction have been published in recent years, allowing for a systematic evaluation of outcomes.

Purpose:

To summarize outcomes at ≥20 years after ACL reconstruction and identify patient and surgical factors that affect these results.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Prospective studies of primary ACL reconstructions with hamstring or bone–patellar tendon—bone (BTB) autograft via an arthroscopic or a mini-open technique and with a mean follow-up of ≥20 years were identified. When possible, the mean scores for each outcome measure were calculated. Factors identified in individual studies as predictive of outcomes were described.

Results:

Five studies met the inclusion and exclusion criteria with a total of 2012 patients. The pooled mean follow-up for patient-reported outcome measures was 44.2% (range, 29.6%-92.7%) and in-person evaluation was 33.2% (range, 29.6%-48.9%). Four studies (n = 584) reported graft tears at a mean rate of 11.8% (range, 2%-18.5%) and 4 studies (n = 773) reported a contralateral ACL injury rate of 12.2% (range, 5.8%-30%). Repeat non-ACL arthroscopic surgery (4 studies; n = 177) to the ipsilateral knee occurred in 10.4% (range, 9.5%-18.3%) and knee arthroplasty (1 study; n = 217) in 5%. The pooled mean of the International Knee Documentation Committee subjective knee function (IKDC) score was 79.1 (SD, 21.8 [3 studies; n = 644]). In 2 studies (n?= 221), 57.5% of patients continued to participate in strenuous activities. The IKDC-objective score was normal or nearly normal in 82.3% (n = 496; 3 studies), with low rates of clinically significant residual laxity. Moderate-severe radiographic osteoarthritis (OA) (IKDC grade C or D) was present in 25.9% of patients (n = 605; 3 studies). Medial meniscectomy is associated with increased risk of radiographic OA. Radiographic OA severity is associated with worse patient-reported knee function, but the association with knee pain is unclear.

Conclusion:

Currently available prospective evidence for ACL reconstruction with hamstring or BTB autograft provides several insights into outcomes at 20 years. The rates of follow-up at 20 years range from 30% to 93%. IKDC-objective scores were normal or nearly normal in 82% and the mean IKDC-subjective score was 79 points.