Cartilage shear dynamics during tibio-femoral articulation: effect of acute joint injury and tribosupplementation on synovial fluid lubrication

Abstract

Objective To determine the effects of acute injury and tribosupplementation by hyaluronan (HA) on synovial fluid (SF) modulation of cartilage shear during tibio-femoral articulation. Methods Human osteochondral blocks from the lateral femoral condyle (LFC) and tibial plateau (LTP) were apposed, compressed 13%, and subjected to sliding under video microscopy. Tests were conducted with equine SF from normal joints (NL-SF), SF from acutely injured joints (AI-SF), and AI-SF to which HA was added (AI-SF+HA). Local and overall shear strain (Exz) and the lateral displacement (Δx) at which Exz reached 50% of peak values (Δx1/2) were determined. Results During articulation, LFC and LTP cartilage Exz increased with Δx and peaked when surfaces slid, with peak Exz being maintained during sliding. With AI-SF as lubricant, surface and overall Δx1/2 were ~40% and ~20% higher, respectively than values with NL-SF and AI-SF+HA as lubricant. Also, peak Exz was markedly higher with AI-SF as lubricant than with NL-SF as lubricant, both near the surface (~80%) and overall (50–200%). Following HA supplementation to AI-SF, Exz was reduced from values with AI-SF alone by 30–50% near the surface and 20–30% overall. Magnitudes of surface and overall Exz were markedly (~50–80%) higher in LTP cartilage than LFC cartilage for all lubricants. Conclusion Acute injury impairs SF function, elevating cartilage Exz markedly during tibio-femoral articulation; such elevated Exz may contribute to post-injury associated cartilage degeneration. Since HA partially restores the function of AI-SF, as indicated by Exz, tribosupplements may be beneficial in restoring cartilage mechanobiology.

Novel Nano-composite Multilayered Biomaterial for Osteochondral Regeneration

“…In large cartilage lesions, the subchondral bone is involved in the degenerative process as well, and focal chondral defects, if left untreated, may even increase in size over time and present with concomitant changes of the underlying subchondral bone plate, either overgrowth or bone loss. 7,8,40 In fact, the functional conditions of articular cartilage and its supporting bone are tightly coupled because injuries of either type adversely affect the entire joint mechanical environment. The biomechanical perturbations caused by osteochondral alterations substantially alter the pattern and magnitude of contact pressure and cartilage strain in the joint.…”

Tailoring hydrogel surface properties to modulate cellular response to shear loading

“…Similar to native articular cartilage [37, 38], deformation of the hydrogel constructs was highly dependent on their surface friction (Fig. 2F, G).…”

“…This may in turn be involved in the initiation of posttraumatic cartilage degeneration by increasing the magnitude of loading-induced tissue strain beyond a physiological level. Nevertheless, although earlier studies suggested an increase in shear strain following superficial cartilage damage and depleted lubrication [36–38], surprisingly little is known about the functional relationship between the frictional properties of native or tissue-engineered cartilage and chondrocyte behaviour upon mechanical stimulation.…”

Hydrogels and bioreactors for cartilage research and functional tissue engineering

“…To accomplish this, three separate compositions were prepared to yield thin hydrogel sheets containing no SSA (alginate methacrylate, or ALMA; Figure We then proceeded to investigate the deformation of these constructs in response to sliding shear motion replicating the mechanical environment of articular cartilage using a custom microscope-mounted loading device and digital image correlation. Similar to native articular cartilage [72,238], deformation of the , and PEG-80S hydrogel constructs were analysed to determine their (A) dynamic coefficients of friction (mean ± SD, n = 5, *** = p ˂ 0.001), (B) compressive moduli at day 1 (mean + SD, n = 3) and (C) mass swelling ratios (bars) as well as water contents (dots) of bilayered constructs (mean ± SD, n = 3). (D) Cross-sections and (E) quantified attenuation values from EPIC-μCT scans illustrating differences in surface hydrogel negative charge densities in bilayered constructs (attenuation scales range from -5,000 (black) to 20,000 (white)).…”

“…Nevertheless, although earlier studies suggested an increase in shear strain following superficial cartilage damage and depleted lubrication [72,237,238] % and reacted with a 10-fold molar excess of MAAh over total alginate hydroxyl groups for 24 h on ice and under constant stirring [240]. The pH was regularly adjusted to 8 using 5 M NaOH.…”