A Biomechanical, Cadaveric Evaluation Of Single- Versus Double-Row Repair Techniques On Stability Of Bony Bankart Lesions

Background:Previous studies comparing stability between single- and double-row arthroscopic bony Bankart repair techniques focused only on the measurements of tensile forces on the bony fragment without re-creating a more physiologic testing environment.Purpose:To compare dynamic stability and displacement between single- and double-row arthroscopic repair techniques for acute bony Bankart lesions in a concavity-compression cadaveric model simulating physiologic conditions.Study Design:Controlled laboratory study.Methods:Testing was performed on 13 matched pairs of cadaveric glenoids with simulated bony Bankart fractures with a defect width of 25% of the inferior glenoid diameter. Half of the fractures were repaired with a double-row technique, and the contralateral glenoids were repaired with a single-row technique. To determine dynamic biomechanical stability and ultimate step-off of the repairs, a 150-N load and 2000 cycles of internal-external rotation at 1 Hz were applied to specimens to simulate early rehabilitation. Toggle was quantified throughout cycling with a coordinate measuring machine. Three-dimensional spatial measurements were calculated. After cyclic loading, the fracture displacement was measured.Results:The bony Bankart fragment-glenoid initial step-off was found to be significantly greater (P < .001) for the single-row technique (mean, 896 mu m; SD, 282 mu m) compared with the double-row technique (mean, 436 mu m; SD, 313 mu m). The motion toggle was found to be significantly greater (P = .017) for the single-row technique (mean, 994 mu m; SD, 711 mu m) compared with the double-row technique (mean, 408 mu m; SD, 384 mu m). The ultimate interface displacement was found to be significantly greater (P = .029) for the single-row technique (mean, 1265 mu m; SD, 606 mu m) compared with the double-row technique (mean, 795 mu m; SD, 398 mu m).Conclusion:Using a concavity-compression glenohumeral cadaveric model, we found that the double-row arthroscopic fixation technique for bony Bankart repair resulted in superior stability and decreased displacement during simulated rehabilitation when compared with the single-row repair technique.