Higher pain catastrophizing was associated with a reduced pain HRQoL in women with endometriosis at a tertiary referral center, independent of pain severity and other potential confounders.

In terms of cross-sectional correlations, higher levels of baseline pain intensity and interference were associated with higher levels of baseline PTSS (rs = .35 and .36, ps < .001, respectively), more severe insomnia (r = .22, p < .05 and r = .48, p < .001, respectively), and poorer sleep quality (r = -.20, p < .05 and r = -.40, p < .001, respectively), ps < .05. Higher levels of baseline PTSS were associated with poorer sleep quality (r = -.36, p < .001) and more severe insomnia (r = .49, p < .001). Higher pain interference at follow-up was associated with higher levels of follow-up pain intensity (r = .52, p < .001) and 3-month PTSS (r = .25, p < .05). Longer sleep duration was associated with better sleep quality (r = .20, p < .01). Correlations between objectively assessed sleep duration and most of self-report variables were small and nonsignificant (rs ranged from |.02| to |.16|, ps > .05).With regards to longitudinal correlations, higher levels of pain intensity, pain interference, and PTSS at baseline correlated with higher pain intensity, pain interference, and PTSS at follow-up (rs ranged from .24 to .72, ps < .05). Similarly, more severe insomnia and poorer sleep quality at baseline were associated with higher pain intensity, pain interference, and PTSS at follow-up (rs ranged from |.23| to |.43|, ps < .05). Additional Analyses: Child PTSD Symptom scale (CPSS-5) subscales

The objective of this study was to determine the effect of different sliding interface materials (counterface) on the cartilage lubricating ability of proteoglycan 4 (PRG4) and hyaluronan (HA) by measuring the kinetic coefficient of friction on cartilage-glass and cartilage-cartilage interfaces over a wide range of sliding velocities. The lubrication properties of PRG4 and HA were assessed at cartilage-glass and cartilage-cartilage interfaces using a previously described test setup with a stationary area of contact. Samples were articulated at varying effective sliding velocities of 10, 3, 1, 0.3, 0.1, and 0.01 mm/s. The response of PRG4 and HA as effective friction-reducing cartilage boundary lubricants was varied and was dependent primarily on the test counterface. At a physiological cartilage-cartilage interface both HA and PRG4 effectively reduced friction compared to PBS at slower speeds while at higher speeds PRG4 was similar to PBS, and HA similar to SF. Conversely, at a cartilage-glass interface HA demonstrated no friction reducing ability compared to PBS, and PRG4 appeared just as effective as SF. Cartilage-glass friction coefficients were also significantly greater than cartilage-cartilage friction coefficients. These results indicate the in vitro friction coefficient of putative cartilage boundary lubricants can be affected by the test counterface and suggest that use of synthetic surfaces in studying cartilage boundary lubrication may not always be appropriate for all molecules of interest. As such, care should be taken when interpreting such data, specifically when comparing to in vitro data obtained at a cartilage-cartilage interface, and especially when extrapolating to in vivo situations. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

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