Summary

To examine the dynamic stability and ultimate displacement of single- vs double-row repair techniques for acute bony Bankart lesions

Abstract

Background

Single- and double-row arthroscopic reconstruction techniques for acute bony Bankart lesions have been described in the literature. Previous studies comparing single- and double-row reconstruction techniques have examined static forces required to displace the bony Bankart lesion. No studies, to date, have examined the dynamic stability and displacement. We hypothesize the double-row fixation technique would provide superior stability and decreased displacement of a simulated bony Bankart lesion throughout the healing process in a cadaveric model compared with single-row technique.

Methods

Testing was performed on 13 matched pairs of glenoids 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. To determine dynamic biomechanical stability and ultimate step-off of the repairs a 150N load and 2000 cycles of internal-external rotation at 1Hz was applied to specimens to simulate standard rehabilitation protocols. Toggle was quantified throughout cycling with a coordinate measuring machine. After cyclic loading, the fracture displacement was measured. 3D spatial measurements were calculated using MATLAB.

Results

The double-row technique resulted in significantly (p=0.005) less displacement (mean=342.48 µm SD=300.64 µm) than single-row technique (mean=981.84 µm, SD=640.38 µm). Ultimate fracture displacement of double-row repair was significantly less (mean=792.23 µm, SD=333.85 µm, p=0.046) after simulated rehabilitation by internal-external rotation cycling compared to single-row repair (mean=1,267.38 µm, SD=640.38 µm).

Conclusion

The double-row fixation technique resulted in superior stability throughout simulated rehabilitation and decreased displacement following simulated rehabilitation in this cadaveric model.