Platelet-rich plasma–assisted nonoperative treatment of acute anterior cruciate ligament injuries: Clinical and MRI outcomes and factors associated with success

Anterior cruciate ligament (ACL) reconstruction is commonly recommended for highly active patients, but interest in biologically augmented nonoperative treatment is increasing. This study evaluated clinical and imaging outcomes and explored factors associated with success after platelet-rich plasma (PRP)-assisted nonoperative treatment of acute ACL injuries. This retrospective case series included 40 highly active patients with magnetic resonance imaging (MRI)-confirmed ACL injuries treated within 6 weeks of injury between 2019 and 2023. PRP injections were combined with bracing and staged rehabilitation, and patients were followed for at least 18 months. Treatment success required restored ACL continuity on MRI, a pivot-shift grade ≤1, return to the preinjury sports level, and no major adverse events or subsequent surgery. ACL continuity was restored in 38 patients (95.0%), and 33 (82.5%) met all success criteria. In exploratory analyses, success was more frequent in patients aged ≥30 years than in younger patients (95.2% vs 68.4%, p = 0.027), in partial than complete tears (100.0% vs 66.7%, p = 0.019), and in femoral-side than mid-substance tears (92.6% vs 61.5%, p = 0.029). All seven treatment failures involved complete tears, and five involved mid-substance tears. However, none of these factors was independently associated with treatment failure in exploratory Firth penalized logistic regression. PRP-assisted nonoperative management yielded favorable clinical and MRI outcomes in this selected cohort. These findings are hypothesis-generating, and the independent contribution of PRP cannot be determined because of the retrospective uncontrolled design and limited number of treatment failures.