Mesenchymal progenitor cells from non-inflamed versus inflamed synovium post-ACL injury present with distinct phenotypes and cartilage regeneration capacity.

Background: Osteoarthritis (OA) is a chronic debilitating disease impacting a significant percentage of the global population. While there are numerous surgical and non-invasive interventions that can postpone joint replacement, there are no current treatments which can reverse the joint damage occurring during the pathogenesis of the disease. While many groups are investigating the use of stem cell therapies in the treatment of OA, we still don't have a clear understanding of the role of these cells in the body, including heterogeneity of tissue resident adult mesenchymal progenitor cells (MPCs).

Tryptase β regulation of joint lubrication and inflammation via proteoglycan-4 in osteoarthritis.

PRG4 is an extracellular matrix protein that maintains homeostasis through its boundary lubricating and anti-inflammatory properties. Altered expression and function of PRG4 have been associated with joint inflammatory diseases, including osteoarthritis. Here we show that mast cell tryptase β cleaves PRG4 in a dose- and time-dependent manner, which was confirmed by silver stain gel electrophoresis and mass spectrometry.

Bone Mineral Density Changes in the Hip and Spine of Men and Women 1-Year After Primary Cemented Total Knee Arthroplasty: Prospective Cohort Study.

This study evaluated age- and sex-adjusted changes in total hip and spine bone mineral density (BMD) within 1 year of total knee arthroplasty (TKA) using a prospective, longitudinal cohort with a one-year follow-up. Preoperatively, subjects underwent routine bone mineral densitometry of their hip and spine, which was repeated 12 months postoperatively. Of 108 subjects, 97 (90%) completed BMD testing.