Labral Augmentation With Either Iliotibial Band Allograft or Dermis Allograft Perform Similarly Regarding Peak Force, Displacement, and Work to Labral Repair in Suction Seal Restoration: A Biomechanical Study

Abstract

PurposeIn order to investigate if allograft substitutes may be utilized to restore suctional seal properties with labral augmentation, the purpose of the current study was to evaluate the biomechanical properties of the labral suction seal under several scenarios, including: (1)intact labrum, (2)rim preparation, (3)labral repair, (4)labral augmentation with iliotibial band (ITB), (5)labral augmentation with a dermis allograft. MethodsEleven hemi-pelvises were dissected to the level of the labrum and placed in a material testing system (MTS) for biomechanical axial distraction. Each specimen was compressed to 250 newtons (N) and distracted at 10 mm/s while load, crosshead displacement, and time were continuously recorded. For each of the five labral states, three testing repetitions were performed. Peak force (N, newtons), displacement at peak force (mm, millimeter), and work (N-mm, newton, millimeter) were calculated and normalized to the intact state of each specimen. ResultsEleven specimens were tested and eight specimens (age: 58.6±5.4 years, BMI: 28.6±6.8 kg/m2; 4 females; 5 right hips) were included in final analyses. Expressed as a percentage relative to the intact state, the average normalized peak force, displacement at peak force, and work for each labral state were as follows: intact (100.0%±0% for all), rim preparation (89.0%±9.2%, 93.3%±20.6%, 85.1%±9.0%), repair (61.3%±17.9%, 88.4%±36.9%, 58.1%±16.7%), ITB allograft (62.7%±24.9%, 83.9%±21.6%, 59.4%±22.4%), and dermis allograft (57.8%±27.2%, 88.2%±29.5%, 50.0%±20.1%). Regarding peak force, intact state was significantly higher compared to the labral repair, augmentation with ITB, and augmentation with the dermis allograft states (p<0.001). No significant differences were demonstrated between displacement at peak force (p=0.561). Regarding work, both intact state and rim preparation states were significantly higher than the repair, ITB augmentation, and dermis allograft augmentation states (p<0.001). In all outcome measures, the dermis allograft augmentation performed with no statistical difference to the ITB augmentation state. ConclusionLabral repair and labral augmentation with either ITB allograft or the dermis allograft resulted in significantly lower peak force and work to equilibrium compared to the intact and rim prep states. There was no statistical difference between repair and augmentation states as well as no statistical difference between ITB allograft and dermal allograft at time zero. Clinical RelevanceThis study compares biomechanical properties of the suction seal of the hip comparing labral states including intact, rim preparation, repair, and augmentation under which can be used for surgical decision making.