Contribution of the Lateral Collateral Ligament on Distribution of Forces in the Canine Elbow: An Ex Vivo Study

Abstract

Objectives: To determine the effects of lateral collateral ligament (LCL) deficiency on load distribution within the joint, specifically contact force, pressure, and area between the medial and lateral compartments of canine cadaveric elbows under simulated axial loading during the stance phase. Additionally, this study aimed to evaluate whether prosthetic ligament reconstruction restores normal biomechanics within the joint.

Study Design: Ex-vivo cadaveric mechanical evaluation

Methods: Elbow joints (N=3) were subjected to four testing conditions using a non-constrained limb press model (condition A: intact LCL, condition B: cranial crus of the LCL transected, condition C: entire LCL transected, condition D: prosthetic LCL placed), with each condition tested in triplicate. Tactile array sensors placed in the medial and lateral compartment allowed continuous direct measurement of contact area, contact pressure and contact force. Limbs were loaded on a calibrated electromechanical testing system to 200 N under each testing condition at a 135-degree standing angle.

Results: Force and contact pressure within the medial compartment increased as a result of full transection of the LCL when compared as a proportion to the lateral compartment (P = 0.023 and P = 0.045 respectively). Placement of a prosthetic LCL did not restore normal intra-articular joint contact mechanics. No significant change in contact area was observed between testing conditions.

Conclusion: A LCL deficient elbow results in increased forces within the medial compartment, prosthetic ligament placement does not entirely restore normal elbow biomechanics. Prosthetic ligament placement may reduce loading of the medial compartment; however, the technique requires further development to reduce variability in loading effect.