Biomechanical comparison of the Latarjet procedure with and without a coracoid bone block.

PURPOSE: The aim of this study was to biomechanically evaluate the Latarjet procedure, with and without a bone block, on glenohumeral range of motion, translation, and kinematics after creation of a bony Bankart lesion.

METHODS

Eight cadaveric shoulders were tested for range of motion, translation, and kinematics in 90° shoulder abduction in both the scapular and coronal planes with the following conditions: intact, Bankart lesion with 20 % glenoid bone loss, Latarjet procedure and soft tissue only conjoined tendon transfer.

RESULTS

There was a significant increase in range of motion in both the scapular and coronal planes with both the Latarjet and conjoined tendon transfer compared to the intact state. The Latarjet procedure restored anterior and inferior translation in both planes. The conjoined tendon transfer restored anterior and inferior translation at lower translational loads, but not with higher loads. Both reconstructions shifted the humeral head apex posteriorly in external rotation.

CONCLUSIONS

The increase in range of motion suggests that the Latarjet procedure does not initially over-constrain the joint. At higher loads, there was improved stability with the Latarjet procedure compared to the conjoint tendon transfer. Both Latarjet and conjoined tendon transfer procedures alter normal joint kinematics by shifting the humeral head apex posteriorly in external rotation.