Cyclical loading of coracoclavicular ligament reconstructions: a comparative biomechanical study

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Sports medicine

Background:

• Acromioclavicular (AC) joint injuries present complex reconstruction challenges.
• Current reconstruction techniques for AC joint injuries lack consensus.
• Evaluating novel graft materials is crucial for improving patient outcomes.

Purpose of the Study:

• To compare the biomechanical performance of semitendinosus tendon autograft versus coracoacromial ligament (CAL) transfer for coracoclavicular (CC) ligament reconstruction.
• To test the hypothesis that semitendinosus tendon graft provides superior mechanical stability over augmented CAL transfer.

Main Methods:

• A controlled laboratory study utilized five cadaveric shoulders.
• Coracoclavicular ligaments were reconstructed using three methods: CAL transfer alone, augmented CAL transfer (Ethibond suture), and semitendinosus tendon graft.
• Reconstructions underwent cyclic loading to simulate physiological stress and determine failure points.

Main Results:

• The semitendinosus tendon graft and augmented CAL transfer demonstrated significantly higher cyclic load survival than non-augmented CAL transfer (P = .008).
• The semitendinosus tendon graft successfully withstood all loading cycles, while the augmented CAL transfer failed during higher load cycles.
• The semitendinosus graft exhibited superior biomechanical integrity under cyclic loading.

Conclusions:

• Coracoclavicular ligament reconstruction using a semitendinosus tendon graft is biomechanically superior to augmented CAL transfer.
• The semitendinosus tendon represents a robust, biologic graft option for CC ligament reconstruction.
• This finding supports the clinical consideration of semitendinosus grafts for AC joint instability.