Summary

To evaluate the effects of suture overlying cartilage in acute bony Bankart repair

Abstract

Background

Single- and double-row arthroscopic reconstruction techniques for acute bony Bankart lesions have been described in the literature. Severe cartilage loss has been described in the setting of shallow anchor placement. There has been no previous investigation into the effects of cartilage loss due to suture from suture anchors overlying the repaired bony fragment. We hypothesize there will be cartilage loss over time due to the presence of suture from suture anchors in acute bony Bankart repairs, and double-row reconstruction will cause increased humeral head cartilage loss due to an overall larger surface area when compared to single-row reconstruction.

Methods

Testing was performed on 24 cadaveric glenoids, 12 right and 12 left, with simulated bony Bankart fractures with a defect width of 25% of the glenoid diameter. Half of the fractures were repaired with a double-row technique, while the contralateral glenoids were repaired with a single-row technique. Samples were randomized by blinded envelopes. Samples were subjected to 20,000 cycles of internal-external rotation across a 90o arc at 2Hz after a compressive load of 750-N or 90% BW, whichever was less, was applied to simulate wear. Cartilage defects were quantified through a custom MATLAB script. Images were excluded for poor quality, or inadvertent tissue folding during tissue processing. Mean cartilage cutout differences were analyzed by Wilcoxon Rank Sum Test.

Results

A total of 92 images were analyzed, 51 double-row and 41 single-row. The double-row technique resulted in significantly (p=0.027) more cartilage cutout (99,746.1 µm2, SD=65,864.8 µm2) than single row repair (mean=68,884.5 µm2, SD=44,373 µm2).

Conclusion

Both the single-row and double-row fixation techniques resulted in damage to the humeral articular cartilage. The double-row fixation technique resulted in significantly increased cutout to humeral head cartilage after simulated wear in this cadaveric model.