Biomechanical Comparison Between Intact Labrum, Labral Tear, Labral Resection, Labral Repair, and Segmental Labral
Steven F DeFroda1,2, Ashwin R Garlapaty2,3, Corder Lehenbauer2,3
1Department of Orthopaedic Surgery, University of Missouri, Columbia, Missouri, USA.
Background:
While labral repair is the preferred treatment for labral tears, reconstruction using allografts is an emerging option when repair is not viable. The biomechanical performance of different reconstructive graft options is not fully understood.
Hypothesis:
Segmental labral reconstructions using fresh meniscal allografts (MALs) or fresh-frozen anterior tibialis tendon allografts (TALs) would not be significantly different from native intact labrum with respect to contact areas, contact pressures, peak forces, and suction seal preservation.
Study Design:
Controlled laboratory study.
Methods:
Eight human cadaveric hips were tested using a biomechanical robotic system in intact, tear, repair, resection, and segmental reconstruction with TAL or MAL states. Specimens were examined in neutral, 20° of extension, and 60° of flexion. In each labral state, contact pressure, contact area, and peak force were recorded using pressure sensors. Suction seal distraction tests were performed in each labral state. Data were normalized to the intact labrum state. Repeated-measures analysis of variance was used to identify differences in biomechanical parameters. Significance was set a priori at a P value <.05.
Results:
Segmental labral reconstruction with fresh MAL produced significantly lower peak force than the intact labrum state at 60° of flexion (74.3% ± 13.6% vs 100%; P = .006). Segmental reconstruction with fresh-frozen TAL induced a significantly higher peak force at 60° of flexion compared with segmental reconstruction with fresh MAL (133% ± 53.7% vs 74.3% ± 13.6%; P = .045). Intact labrum (7/10; 70%), labral tear (9/10; 90%), labral repair (6/10; 60%), labral resection (1/10; 10%), segmental labral reconstruction with fresh-frozen TAL (4/5; 80%), and segmental labral reconstruction with fresh MAL (4/5; 80%) experienced reestablishment of suction seal after distraction.
Conclusion:
Segmental labral reconstruction with fresh MAL resulted in a lower peak force at 60° of flexion and similar rates of suction seal preservation compared with intact labrum. Segmental labral reconstruction with fresh MAL resulted in a lower peak force at 60° of flexion compared with segmental reconstruction with fresh-frozen TAL. Biomechanically, segmental labral reconstruction with fresh MAL may be superior to fresh-frozen TAL in the cadaveric model.
Clinical Relevance:
Understanding the biomechanical performance of various labral reconstruction graft options may guide surgical decision-making in patients who require labral reconstruction.
