Cadaveric biomechanical study of the elbow collateral ligaments. It measured when each ligament is taut through the flexion arc and tested the failure load, stiffness, and strength of each. Values were compared to the palmaris longus tendon, the standard reconstruction graft.
When you evaluate elbow valgus instability, remember that the AMCL is the primary restraint at 90 degrees of flexion, while the bony articulation shares the load in full extension. This is the anatomic reason the moving valgus stress test and UCL injuries in throwers center on the anterior bundle.
The strength data justifies the Tommy John reconstruction. The palmaris longus graft is roughly 4x stronger than the ligament it replaces, so failure is rarely a graft-material problem.
The practical pitfall the authors emphasize is tunnel placement. Because the graft is much stiffer than native tissue, origin and insertion must match the native AMCL footprint precisely, or you trade stiffness for lost motion or residual laxity.
On the lateral side, the LUCL is the structure that fails in posterolateral rotatory instability, which is the true lesion behind most recurrent elbow dislocations rather than the medial complex.
Cadaveric biomechanical study of the elbow collateral ligaments. It measured when each ligament is taut through the flexion arc and tested the failure load, stiffness, and strength of each. Values were compared to the palmaris longus tendon, the standard reconstruction graft.
When you evaluate elbow valgus instability, remember that the AMCL is the primary restraint at 90 degrees of flexion, while the bony articulation shares the load in full extension. This is the anatomic reason the moving valgus stress test and UCL injuries in throwers center on the anterior bundle.
The strength data justifies the Tommy John reconstruction. The palmaris longus graft is roughly 4x stronger than the ligament it replaces, so failure is rarely a graft-material problem.
The practical pitfall the authors emphasize is tunnel placement. Because the graft is much stiffer than native tissue, origin and insertion must match the native AMCL footprint precisely, or you trade stiffness for lost motion or residual laxity.
On the lateral side, the LUCL is the structure that fails in posterolateral rotatory instability, which is the true lesion behind most recurrent elbow dislocations rather than the medial complex.