A Biomechanical Comparison of Repair Techniques for Complete Gluteus Medius Tears

Abstract

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. CLINICAL RELEVANCE: 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.