Quantitative determination of joint incongruity and pressure distribution during simulated gait and cartilage thickness in the human hip joint

Abstract

The objective of this study was to provide quantitative data on hip-joint incongruity and pressure during a simulated walking cycle and on articular-cartilage thickness in the same set of specimens. Using a casting technique in eight specimens of the human hip (age: 18-75 years), we determined the width of the joint space (incongruity) required at minimal load for contact at four phases of the gait cycle. The pressure distribution, measured with pressure-sensitive film, was determined at physiologic load magnitudes on the basis of in vivo measurements of hip-joint forces. Cartilage thickness was assessed with A-mode ultrasound. At minimal loading, the average maximum width of the joint space ranged from 1.1 to 1.5 mm in the acetabular roof, with the contact areas located ventro-superiorly and dorso-inferiorly throughout the gait cycle. At physiological loading, the width decreased and the contact areas covered the complete articular surface during midstance and heel-off but not during heel-strike or toe-off. The pressure distribution was inhomogeneous during all phases, with average maximum pressures of 7.7 +/- 1.95 MPa at midstance. The cartilage thickness varied considerably throughout the joint surfaces; maxima greater than 3 mm were found ventro-superiorly. These data can be used to generate and validate computer models to determine the load-sharing between the interstitial fluid and the solid proteoglycan-collagen matrix of articular cartilage, the latter being relevant for the initiation of mechanically induced cartilage degeneration.

The Hip Stress Level Analysis for Human Routine Activities

“…This range is similar to those measured by other authors with instrumented implants [30][31][32][33][34][35][36]; the peak stress distributions have a double peak curve during walking (see Fig. 2, 3), and the larger peak stress is often happened in the walking fast case.…”

Concentration of the CS-846 Epitope in Serum and Synovial Fluid of Horses with Different Grades of Osteochondral Fragments in the Carpal Joints

“…D'Lima et al [31] found 47% apoptosis in cell cultures of bovine chondrocytes that received pressure loads of 23 megapascals (MPa) for 48 hours. If we assume that 7 MPa is the upper limit of physiological stress of cartilage [32], this might suggest that a stress load that causes osteochondral fracture, such as grade 4 OF, may be sufficient to induce apoptosis of these cells, which could significantly compromise the synthesis of PG. Other studies suggest that the dislocation of results in a lower loading of the cartilage, which could influence the synthetic activity of the chondrocytes [33].…”

Basic fibroblast growth factor mediates transduction of mechanical signals when articular cartilage is loaded

“…These loads are considered to be within the normal physiologic range generated during weight bearing. For example, peak compressive stresses in humans while walking range from 5 to 8 MPa (32,33). Secretion of proteins by isolated chondrocytes following interleukin-1 (IL-1) and growth factor stimulation.…”