Superior Primary Stability of a Knotless Double-Row Construct Compared to Mason-Allen Repair for Anatomical Refixation of Gluteal Tendons-Biomechanical Human Cadaver Study.

Abstract

Objectives: Hip abductor tendon tears remain an underrecognized diagnosis, initially classified under Greater Trochanteric Pain Syndrome. This often results in ineffective conservative treatment, providing only temporary pain relief. While certain surgical approaches, particularly knotless double-row repair techniques (Hip Bridge) have shown promising clinical outcomes, comprehensive biomechanical data remain insufficient. Therefore, this study aimed to biomechanically compare Hip Bridge (HB) repair with the standard Mason-Allen (MA) technique using a human cadaver model.

Methods: Gluteus minimus and medius were released in 12 fresh-frozen human cadaveric specimens and reattached to their anatomical footprints either with transosseous MA or knotless double-row HB technique. HB consisted of two proximal PEEK (polyetheretherketone) anchors, each preloaded with double-V shaped tapes, crossed, and distally fixated with two additional anchors. Femurs were fixated in a custom-made sample holder while gluteal muscles were clamped using a cryo-jaw. The construct underwent a cyclic loading test between 10 and 125 N for 150 cycles at 2.5 Hz (preload 10 N), followed by a pull-to-failure test. Failure mode and elongation were determined, the latter by a 3D optical measurement system. Statistical analysis was performed using t-test.

Results: HB repair resulted in significantly higher ultimate failure loads (339.1 ± 144.4 N) compared to the MA technique (209.6 ± 62.1 N, p = 0.0381). HB failed exclusively due to tendon failure, whereas MA exhibited different failure modes: tendon failure (1/6), bone cutting (4/6), and muscle rupture (1/6). During cyclic loading, the calculated final plastic elongation was 4.4 ± 0.5 mm for MA and 3.4 ± 1.4 mm for HB (p = 0.0731). During pull-to-failure testing, stiffness of 59.7 ± 12.5 N/mm (MA) and 66.8 ± 18.4 N/mm (HB) was observed (p = 0.247).

Conclusion: The HipBridge technique provides superior biomechanical stability compared to the standard Mason-Allen repair, showing significantly higher ultimate failure load and reduced failure variability. This advantage may be attributed to greater contact restoration of the anatomical footprint, which is particularly beneficial for treating weakened tendons and bones in elderly patients.