Labral Reconstruction with Iliotibial Band Autograft and Semitendinosus Allograft Improves Hip Joint Contact Area and Contact Pressure: An In-Vitro Analysis

Objectives: Labral reconstruction using iliotibial band (ITB) autograft and semitendinosus (Semi-T) allograft have recently been described in cases of labral deficiency. The current study seeks to understand the biomechanical effects of an intact labrum, segmental labral resection, and labral reconstruction on joint contact area, contact pressure, and peak force. Methods: Ten fresh-frozen human cadaver hips were analyzed utilizing thin-film piezoresistive load sensors to measure contact area, contact pressure, and peak force 1) with the native intact labrum, 2) after segmental labral resection and 3) after graft labral reconstruction with either ITB autograft or Semi-T allograft. Each specimen was examined at 20° extension and 60° flexion. Statistical analysis was conducted through one-way ANOVA with post-hoc Games-Howell tests. Results: For the ITB group, labral resection significantly decreased contact area (20°: 73.2%±5.38, P=0.0010; 60°: 78.5%±6.93, P=0.0063) and increased contact pressures (20°: 106.7%±4.15, P=0.0387; 60°: 103.9%±1.15, P=0.0428). ITB reconstruction improved contact area (20°: 87.2%±12.3, P=0.0130; 60°: 90.5%±8.81, P=0.0079) and contact pressures (20°: 98.5%±5.71, P=0.0476; 60°: 96.6%±1.13, P=0.0056) from the resected state. Contact pressure at 60° flexion was significantly lower compared to the native labrum (P = 0.0420). For the Semi-T group, labral resection significantly decreased contact area (20°: 68.1±12.57, P=0.0002; 60°: 67.5%±6.70, P=0.0002) and increased contact pressures (20°: 105.3%±3.73, P=0.0304; 60°: 106.8%±4.04, P=0.0231). Semi-T reconstruction improved contact area (20°: 87.9%±7.95, P=0.0087; 60°: 92.9%±13.2, P=0.0014) and contact pressures (20°: 97.1%±3.18, P=0.0017; 60°: 97.4%±4.39, P=0.0027) from the resected state. Comparative analysis demonstrated no statistically significant differences between either graft reconstruction in relation to contact area, contact pressure, or peak forces. (Figure 1). Conclusion: Segmental anterosuperior labral resection results in significantly decreased contact area and increased contact pressures, while labral reconstruction partially restores time-zero acetabular contact areas and pressures as compared to the resected state. Although labral reconstruction improved the measured biomechanical properties as compared to the resected state, some of these properties remained significantly different compared to the native intact labrum

The Natural History of Femoroacetabular Impingement

Femoroacetabular impingement (FAI) is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis, however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to osteoarthritis. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing osteoarthritis and the need for future arthroplasty