Etiology of Failed Anterior Cruciate Ligament Reconstruction: a Scoping Review

Purpose of Review Recent literature was reviewed to identify and summarize the etiology of primary anterior cruciate ligament (ACL) reconstruction (ACLR) failure reported. Methods The databases Embase, PubMed, and Medline were searched on March 10, 2022, for English-language, clinical studies that reported on the etiology of failure of primary ACLR. The studies were systematically screened in duplicate and data abstracted. Recent Findings Forty-three studies were identified that reported mode of failure in primary ACLR. Trauma (43 studies), technical error (11 studies), and biology (9 studies) remain the most reported etiologies of ACLR failure. A combination of causes was listed in three studies. No reported cause or “other” was listed in 22 studies. Summary Many clinical studies fail to report etiology of ACLR failure. Level of detail provided regarding mode of failure varies widely. Trauma, technical error, and biological failure remain the leading etiologies of ACLR failure reported in recent literature. Technical error is likely underreported and a contributing factor in traumatic failures.