Joint contact behavior in the native, ligamentum teres deficient and surgically reconstructed hip: A biomechanics study.

Abstract

The ligamentum teres is known to contribute to hip joint stability; however, the effect of surgical reconstruction of ligamentum teres tears on hip joint function is poorly understood. This study aimed to employ a cadaver model to quantify peak pressure, average pressure, contact force, and contact area between the femoral head and acetabulum in native, ligamentum teres deficient and reconstructed hips. Nine fresh-frozen human cadaveric hips were dissected and mounted to a multi-axis Materials Test System. Digital pressure sensors were placed on anterior, posterior, and superior regions of the acetabulum. Joint loading was simulated in 20deg flexion, neutral position, and 10deg extension. Peak pressure, average pressure, contact force, and contact area were measured. Ligamentum teres deficiency caused a significant increase in average pressure (mean difference: 161.6 kPa, p = 0.002) in the superior acetabulum of the neutral hip relative to the ligament intact hip and in peak pressure (mean difference: 1462.5 kPa, p = 0.023) in the anterior acetabulum of the extended hip compared to the intact hip. Ligamentum teres reconstruction subsequently restored average and peak pressure to levels not significantly different from those in the intact state (p > 0.05). Reconstruction also led to a significant decrease in average pressure (mean difference 241.0 kPa, p = 0.047) and contact force (mean difference: 124.5 N, p = 0.039) in the posterior acetabulum of the flexed hip relative to the intact hip. Ligamentum teres reconstruction may help to prevent excessive contact that occurs in the ligamentum teres deficient hip and may mitigate or slow the onset of degenerative changes associated with ligamentum teres deficiency.