Objectives: To present clinical outcomes of 2 years duration in a prospective case series of a biologic augmentation technique using intra-ligamentous and intra-articular infiltration of mononuclear cells sourced from bone marrow aspirate concentrate (BMAC) and growth factors derived from platelet-rich plasma (PRP) under arthroscopic visualization for the treatment of isolated and acute partial anterior cruciate ligament (ACL) tears.

Methods: Soccer athletes with an acute symptomatic partial ACL tear who had clinical examination findings of increased anterior tibial translation without rotational instability were treated with biologic augmentation of the injured ligament. Intra-ligamentous infiltration of the ACL followed by intra-articular injection was performed using bone marrow aspirate concentrate and platelet-rich plasma. Patients were followed for 2 years post-operatively with subjective and objective assessment tools. The Lysholm Knee Questionnaire, IKDC Objective score, physical examination findings, MRI, and the KT-1000 arthrometer were used to examine clinical outcome.

Results: Five patients were included in the analysis after undergoing the biologic augmentation treatment of acute partial ACL injury. Median patient age at the time of treatment was 22 years (range 16-30 years). All patients were determined to have a healed ACL on MRI performed 8 months post-operatively. The median Lysholm score at final follow-up of 99 was significantly increased from the median pre-operative score (p=0.042). The objective IKDC score improved in all patients post-operatively, and no clinical examination findings of knee instability were identified at final follow-up. The median side-to-side difference in KT-1000 arthrometer testing was 3 mm pre-operatively and 0 mm at the final 2 year assessment (p=0.038).

Conclusions: The treatment of appropriately indicated symptomatic partial ACL injuries in this study has demonstrated that anatomic or near-anatomic restoration of ligamentous structure and function may be provided by use of a biologic augmentation technique using intra-ligamentous and intra-articular infiltration of mononuclear cells sourced from bone marrow aspirate concentrate and growth factors derived from platelet-rich plasma. This technique is safe, reproducible, performed with minimal technical difficulty, and has led to excellent 2 year clinical outcomes in this prospective case series of patients.