Augmenting an Allograft for Anterior Cruciate Ligament Reconstruction With a Collagen Matrix and Bone Marrow Aspirate...

To evaluate clinical outcomes of augmenting an anterior cruciate ligament (ACL) allograft with an amnion matrix wrap and injecting bone marrow aspirate concentrate (BMAC).

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.

We assessed the longitudinal outcomes of allograft augmentation using descriptive statistics and confidence intervals, showing significant increases in average Knee Injury and Osteoarthritis Outcome Score (KOOS₅) and Single Assessment Numerical Evaluation (SANE) scores (KOOS₅: 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.

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 IV, therapeutic case series.