Anterior Cruciate Ligament Reconstruction in Patients Over 40 Years Old Shows Low Failure Rates: A Systematic Review.

Purpose: To review the literature reporting on complications and failure rates after primary anterior cruciate ligament reconstruction (ACLR) in patients ≥40 years. Methods: This was a secondary analysis from a prior systematic review of the MEDLINE, CINAHL, SportDiscus, Embase, Web of Science, and Cochrane databases on studies evaluating clinical outcomes in ACLR patients ≥40 years. Studies were included based on the following criteria: English-language studies reporting on postoperative complications and/or ACLR failure rates in patients ≥40 years. Case reports, technical notes, studies with duplicate reporting of patient cohorts, or studies using publicly available registry data were excluded. ACLR failure definitions, failure rates, graft rupture rates, revision ACLR and non-ACLR revision rates, and complication rates were recorded. Results: Twenty-one studies were included following full-text review. Autografts were used in 89.0% of cases. Definitions for ACLR failure varied, ranging from (1) revision ACLR, (2) graft rupture, (3) clinical examination of increased knee laxity, and (4) postoperative arthrofibrosis requiring an additional surgery. The median ACLR failure rate was 5.0% (range, 0%-12.1%) among the 9 studies reporting this outcome, with only 4 of the studies providing explicit definitions of failure. The median ACLR revision surgery, graft rupture, and non-ACLR revision surgery rates were 0% (range, 0%-7.7%), 2.7% (range, 0%-9.1%), and 7.2% (range 0%-34.4%), respectively. Commonly reported complications included pain (range, 0%-14.0%), stiffness (range, 0%-12.7%), hematoma (range, 2.5%-8.8%), neurovascular (range, 0%-41.7%), and undefined (range, 0%-13.8%). Conclusions: ACLR in patients over 40 years old shows low failure rates. Level of Evidence: Level IV, systematic review of Level II-IV studies.