This first-in-human cohort study reports 12- and 24-month outcomes of the BEAR procedure, a novel ACL repair technique using a bovine extracellular matrix scaffold soaked in autologous blood. Ten patients underwent BEAR and 10 underwent hamstring autograft ACLR at a single center, with blinded examiners assessing physical exam, patient-reported, and functional outcomes. The study asks whether scaffold-enhanced primary ACL repair can match reconstruction without sacrificing a healthy tendon.
ACL reconstruction works, but it comes with a known cost: harvesting the hamstring tendons causes 10-50% strength deficits that persist for years. BEAR proposes a different trade-off — repair the native ligament instead, preserve the donor tendons, and potentially keep more biology intact.
When you see a young, active patient with an acute complete ACL tear presenting within a month of injury and MRI confirming at least 50% tibial remnant, BEAR eligibility criteria are met. This paper established that the procedure is safe and produces equivalent 2-year outcomes to hamstring ACLR in that specific population.
The practical implication is not that BEAR replaces ACLR today — the sample is 10 patients and the trial nonrandomized. It is that hamstring strength recovery is a real, measurable, clinically relevant advantage that warranted the larger RCT (BEAR II, NCT02664545) that followed.
One nuance worth knowing: the ACLR group's AP laxity worsened between 6 months and 2 years (0.78 mm to 3.14 mm side-to-side), consistent with previously reported autograft stretch-out. The BEAR group trended the other direction (2.36 mm to 1.94 mm), suggesting the healing ligament may stiffen over time rather than creep.
This first-in-human cohort study reports 12- and 24-month outcomes of the BEAR procedure, a novel ACL repair technique using a bovine extracellular matrix scaffold soaked in autologous blood. Ten patients underwent BEAR and 10 underwent hamstring autograft ACLR at a single center, with blinded examiners assessing physical exam, patient-reported, and functional outcomes. The study asks whether scaffold-enhanced primary ACL repair can match reconstruction without sacrificing a healthy tendon.
ACL reconstruction works, but it comes with a known cost: harvesting the hamstring tendons causes 10-50% strength deficits that persist for years. BEAR proposes a different trade-off — repair the native ligament instead, preserve the donor tendons, and potentially keep more biology intact.
When you see a young, active patient with an acute complete ACL tear presenting within a month of injury and MRI confirming at least 50% tibial remnant, BEAR eligibility criteria are met. This paper established that the procedure is safe and produces equivalent 2-year outcomes to hamstring ACLR in that specific population.
The practical implication is not that BEAR replaces ACLR today — the sample is 10 patients and the trial nonrandomized. It is that hamstring strength recovery is a real, measurable, clinically relevant advantage that warranted the larger RCT (BEAR II, NCT02664545) that followed.
One nuance worth knowing: the ACLR group's AP laxity worsened between 6 months and 2 years (0.78 mm to 3.14 mm side-to-side), consistent with previously reported autograft stretch-out. The BEAR group trended the other direction (2.36 mm to 1.94 mm), suggesting the healing ligament may stiffen over time rather than creep.