Augmenting an Allograft for Anterior Cruciate Ligament Reconstruction With a Collagen Matrix and Bone Marrow Aspirate Concentrate Injection Appears Safe and Produces Favorable Clinical Outcomes at 2‐Year Follow‐Up

Purpose: To evaluate clinical outcomes of augmenting an anterior cruciate ligament (ACL) allograft with an amnion matrix wrap and injecting bone marrow aspirate concentrate (BMAC). Methods: We enrolled 10 ACL reconstruction patients aged 22-60 years with hamstring allografts wrapped with an amnion collagen matrix and injected with BMAC in this prospective case series. Participants completed physical therapy and reported outcomes for 2 years. Postoperative magnetic resonance imaging scans were mapped/processed at 3, 6, 9, and 12 months, yielding mean transverse relations time constant (T2∗) and volume values for grafts and bone tunnel integration. Results: : Baseline-24 months [m] = 64.2-84.8, 95% confidence interval [CI] 9.14-32.56, SANE: Baseline-24m = 33.8-87.9, 95% CI 38.71-64.87). Average Veterans RAND 12 Item Health Survey (VR-12) Physical scores significantly increased from baseline to 24 months postoperation (Baseline-24m = 35.1-49.6, 95% CI 8.25-20.30). Average visual analog scale for pain scores significantly decreased from baseline at all time points except 2 weeks postoperation (baseline-2 weeks = 2.7-3.6, 95% CI -0.19 to 2.07) starting at 6 weeks postoperation (baseline-6 weeks = 2.7-1.3, 95% CI -2.52 to -0.26) and remained significantly lower than baseline to 24 months postoperation (baseline-24m = 2.7-0.6, 95% CI- 3.27 to -0.85). Average Max Activity Scale scores were significantly decreased from baseline starting at 12 months postoperation (baseline-12m = 6.3-2.7, 95% CI -6.32 to -0.88) but returned to baseline levels at 24-months postoperation (Baseline-24m = 6.3-5.8, 95% CI -4.45 to 1.45). There were no significant differences in VR-12 mental component scores or magnetic resonance imaging measures. No infections nor reconstruction failures occurred after 2 years. Conclusions: This case series demonstrated augmenting hamstring allograft ACL reconstruction with an amnion collagen matrix and injecting BMAC appeared to be safe, and clinical outcomes were favorable up to 2 years postoperation despite having no quantifiable effect on graft maturation. Level of Evidence: Level IV, therapeutic case series.