Overlying Suture Causes Chondrolysis in Surgical Treatment of Acute Bony Bankart Lesions

OBJECTIVES: Severe cartilage loss has been described in the setting of shallow anchor placement in arthroscopic shoulder surgery. There has been no previous investigation into the effects of cartilage loss due to suture from suture anchors overlying the repaired bony fragment. Current arthroscopic techniques for bony Bankart repair involve placement of suture overlying articular cartilage. 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 2 Hz 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 chondrolysis to the humeral head after simulated wear in this cadaveric model. Despite the biomechanical superiority of double-row repair, surgeons must be aware of the increased rate of chondrolysis involved with this technique.