Abstract
Hypothesis
Recurrent shoulder dislocation is associated with bony defect of the glenoid rim, commonly seen along with bankart tear - a soft tissue injury of glenoid labrum. This cadaveric study compares the bone block effect of coracoid transfer using using two common techniques, Classical Latarjet technique and the Congruent-Arc Latarjet. We hypothesized that the force needed to dislocate the shoulder would be greater in Congruent Arc technique than the Classical Latarjet, because of increased contact surface area as a result of greater linear dimensions.
Material and methods
We dissected 14 cadaveric shoulders. A bony Bankart lesion was created in form of an inverted pear glenoid. The humeral head was attached to a pulley system that was sequentially loaded until the shoulder dislocated anteriorly. The force needed to dislocate was noted. This was repeated after coracoid transfer with two common techniques, Classical Latarjet technique and the Congruent-Arc Latarjet.
Results
The mean force required to dislocate shoulder post-Classical Latarjet technique was 325.71N, compared to 123.57 N in uncorrected shoulder. Similarly, the mean force required to dislocate shoulder post Congruent-Arc Latarjet technique was 327.14 N compared to 123.57 N in uncorrected shoulder. The two-tailed P value in either case was less than 0.0001, thus statistically significant. Unpaired t-test was done to compare the force required to dislocate the shoulder post procedure. Mean force required to dislocate shoulder post-Classical Latarjet, was 325.7N compared to 327N in post-Congruent Arc. The two-tailed P value equals 0.9020 and the 95% confidence interval was from −25.05 to 22.19, thus the difference was not statistically significant.
Conclusion
The results confirm that both (Classical and Congruent-Arc Latarjet) techniques are good for addressing the shoulder instability, however bone block effect provided by one is not superior to other.
