A biomechanical comparison of repair techniques for complete gluteus medius tears.

Abstract

The purpose of this study was to compare the biomechanical fixation stability conferred by 2 specific arthroscopic repair techniques for complete gluteus medius tendon tears. Twelve fresh-frozen human cadaveric hemi-pelves were tested. Six received double-row repair with massive cuff stitches (DR-MCS), whereas the remaining 6 underwent double-row repair with knotless lateral anchors (DR-KLA). Constructs were preloaded to 10 N, tested from 10 N to 125 N at 90 N/s for 150 cycles, and then loaded to failure at 1 mm/s. Markers were placed on the tissue for video tracking. No significant differences in cyclic outcomes were observed. The DR-KLA construct showed a significantly higher normalized yield load than the DR-MCS construct. Post-yield extension for the DR-MCS construct was significantly higher than that for the DR-KLA construct. At yield load, the optically measured soft-tissue elongation of the DR-KLA construct was significantly higher than that of the DR-MCS construct. This study strongly suggests that the biomechanical stability conferred by DR-MCS and DR-KLA constructs for gluteus medius tendon repair is similar. Because the failure load of the DR-KLA construct is strongly correlated to bone mineral density (BMD), clinical considerations of bone quality may be particularly important for gluteus medius repairs. Maximum load was strongly correlated to BMD in the DR-KLA group. On the basis of this analysis, BMD should be considered during surgical planning.