Background: The anterior cruciate ligament (ACL) is a commonly injured ligament in the knee. Bone tunnel widening is a known phenomenon after soft-tissue ACL reconstruction and etiology and clinical relevance have not been fully elucidated. Osteoconductive compounds are biomaterials providing an appropriate scaffold for bone formation such as demineralized bone matrix. Osteoinductive materials contain growth factors stimulating bone lineage cells and bone growth. A possible application of osteoinductive/osteoconductive (OIC) material is in ACL surgery. Questions/Purposes: We hypothesized that OIC placed in ACL bone tunnels: 1) reduces tunnel widening, 2) improves graft maturation and 3) reduces tunnel ganglion cyst formation. To test this hypothesis, this study evaluated the osteogenic effects of demineralized bone matrix (DBM) and platelet rich plasma (PRP) on tunnel widening, graft maturation, and ganglion cyst formation. Study Design: Randomized controlled clinical trial pilot study.   Methods: A total of 26 patients electing ACL reconstruction surgery were randomized between OIC and control group. Measurements of tunnel expansion and graft-tunnel incorporation were conducted via quantitative image analysis of MRI scans performed at six months after surgery for both groups. Results: No patients had adverse post-operative reactions or infections. The use of OIC significantly reduced tunnel widening (p < 0.05) and improved graft maturation (p < 0.05). Patients treated with OIC presented with a significantly lower prevalence of ganglion cyst compared to the control group (p < 0.05). Conclusion: The use of OIC has measurable effects on the reduction of tunnel widening, improved graft maturation and decreased size of ganglion cyst after ACL reconstruction. Clinical Relevance:    This study explored the utilization of biologics to minimize bone tunnel widening in ACL reconstruction surgery.   Study Design: Randomized controlled clinical trial.

The authors have declared no competing interest.

ClinicalTrials.gov Identifier: NCT04993339

The project described was supported by Grant Number GR004579 from Arthrex, Inc (www.arthrex.com) awarded to FT. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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this study was approved by the IRB of the University of Miami (IRB ID:20150981). Patient enrollment was conducted via written consent form.

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