Anterior Cruciate Ligament Reconstruction in Patients Aged 50 Years and Older Results in Improvements in Activity and Functional Outcome Measures, Whereas Reported Complication Rates Vary Widely: A Systematic Review.

Purpose: To systematically review the contemporary literature and evaluate patient-reported outcome measures (PROMs), functional knee measures, and the incidence of complications in patients aged 50 years and older undergoing anterior cruciate ligament reconstruction (ACLR) at short- to mid-term follow-up.

Methods: A literature search was conducted across the PubMed, Embase, and Scopus databases, spanning from database inception to November 2023, in accordance with the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. The inclusion criteria consisted of clinical studies reporting PROMs, measures of knee stability, and complication rates after ACLR in patients aged 50 years and older with minimum 2-year follow-up. The Methodological Index for Non-randomized Studies criteria were used to assess study quality. Primary outcome measures consisted of changes in PROMs and complication rates after ACLR.

Results: A total of 17 studies, consisting of 1,163 patients undergoing ACLR, were identified. Autografts were used in 90.3% of patients, whereas 9.7% of patients were treated using allografts. At minimum 24-month follow-up, mean International Knee Documentation Committee scores ranged from 67.4 to 92.96; mean Lysholm scores, from 84.4 to 94.8; and mean Tegner scores, from 0.3 to 5.4. The mean side-to-side difference at final follow-up ranged from 1.2 to 2.4 mm, and the rates of recurrent instability ranged from 0% to 18%. Complication and revision rates ranged from 0% to 40.4% and 0% to 37.5%, respectively, with the highest rates observed in studies noting a high incidence of intraoperative cartilage lesions.

Conclusions: ACLR in patients aged 50 years and older results in favorable International Knee Documentation Committee scores, Lysholm scores, and Tegner activity scores and improvements in functional knee measures. However, a wide range of reoperations and complications are reported, attributed to varying levels of chondral injury and osteoarthritis, which warrant consideration when discussing expectations in patients aged 50 years and older undergoing ACLR.

Level of evidence: Level IV, systematic review of Level II to IV studies.