Stress And Strain At The Lateral Collateral Ligament Complex Of The Elbow Joint

Background: The radial collateral ligament was previously believed to be the only ligament existing at the lateral aspect of the elbow joint until Morrey and An (1976) classified the ligaments to include radial collateral (RCL) and lateral ulnar collateral ligaments (LUCL). There is therefore the need to assess the impact these ligaments in elbow joint stability. Objective: To investigate how the RCL and LUCL are affected by stress and strain in both routine and forceful movements of the limb. Materials and Methods: Eight (8) embalmed upper extremities were used for this investigation. The elbow joint was dissected with care taken to preserve the lateral ulnar collateral ligament seen in seven of the limbs. Qualitative assessment of ligament tension was made under valgus and varus stresses. The angles at which stress was applied were 450, 700, 750, 900, 1100, 1200 and full extension. These angles were chosen partly because most movements during racket sporting activities take place at higher angles (Regan et al 1991). The angles were determined by hand held goniometer while the arm was firmly held in a retort stand. Results: The RCL is more able to absorb stress and strain because of its greater flexibility enhanced by its attachment at the annular ligament. However, LUCL a thickened mass, in both valgus and varus stresses was taut throughout most of the entire arc of flexion. It is a much stronger ligament that effectively stabilizes elbow joint in both routine and forceful movement. Conclusion: This study has been able to establish that LUCL is more prone to stress and strain. Being attached from bone to bone, it equally provides greater stability at the lateral aspect of elbow joint. KEY WORDS: Elbow joint; Ulna and Radial Collateral Ligament; stress and strain.