Knee Osteoarthritis: A Review of Pathogenesis and State-Of-The-Art Non-Operative Therapeutic Considerations

Abstract

Being the most common musculoskeletal progressive condition, osteoarthritis is an interesting target for research. It is estimated that the prevalence of knee osteoarthritis (OA) among adults 60 years of age or older is approximately 10% in men and 13% in women, making knee OA one of the leading causes of disability in elderly population. Today, we know that osteoarthritis is not a disease characterized by loss of cartilage due to mechanical loading only, but a condition that affects all of the tissues in the joint, causing detectable changes in tissue architecture, its metabolism and function. All of these changes are mediated by a complex and not yet fully researched interplay of proinflammatory and anti-inflammatory cytokines, chemokines, growth factors and adipokines, all of which can be measured in the serum, synovium and histological samples, potentially serving as biomarkers of disease stage and progression. Another key aspect of disease progression is the epigenome that regulates all the genetic expression through DNA methylation, histone modifications, and mRNA interference. A lot of work has been put into developing non-surgical treatment options to slow down the natural course of osteoarthritis to postpone, or maybe even replace extensive surgeries such as total knee arthroplasty. At the moment, biological treatments such as platelet-rich plasma, bone marrow mesenchymal stem cells and autologous microfragmented adipose tissue containing stromal vascular fraction are ordinarily used. Furthermore, the latter two mentioned cell-based treatment options seem to be the only methods so far that increase the quality of cartilage in osteoarthritis patients. Yet, in the future, gene therapy could potentially become an option for orthopedic patients. In the following review, we summarized all of the latest and most important research in basic sciences, pathogenesis, and non-operative treatment.

Portable Knee Health Monitoring System by Impedance Spectroscopy Based on Audio-Board

“…Although this paper in mainly focused on the instrumentation we have developed, in order to address the topic covered in this subsection, it might be useful to briefly discuss some aspects relative to the physiological parameters associated with the intracellular resistance of the knees. The resistance Rin is mainly associated to the articular cartilage cells' metabolism [36] (chondrocytes are the only cell type in the cartilage tissue [37]). This metabolism is stimulated by mechanical loading, detected by the mechanoreceptors on the cell surface [38].…”

“…This metabolism is stimulated by mechanical loading, detected by the mechanoreceptors on the cell surface [38]. In Reference [36], it is explained that through the process of mechanotransduction: mechanical signals modulate the biochemical activity of chondrocytes, regulating metabolic activities by influencing the state of the knee joints. In particular, dynamic compressions during moderate exercise generate mechanical stimuli that can regulate the metabolic balance, thus preventing the progression of cartilage damage [38].…”

Comprehensive Review of Knee Osteoarthritis Pharmacological Treatment and the Latest Professional Societies’ Guidelines

“…The positive results of NSAID therapy are of no surprise from a pathophysiologic point of view, as the key driver of OA progression is a low-grade chronic inflammation caused by an imbalance between anabolic and catabolic processes of the articular osteochondral unit [ 35 ].…”

“…According to Steinmeyer and co-authors, glucosamine and chondroitin sulfate are in a group of symptomatic slow-acting drugs in osteoarthritis (SYSADOA) [ 29 ]. Glucosamine is a metabolic precursor of glycosaminoglycans, which are the components of the cartilage extracellular matrix (ECM), and chondroitin sulfate is a natural component of the ECM [ 35 , 36 ]. Evidence of the positive effects of glucosamine and chondroitin sulfate is still a matter of debate.…”

Evidence of Chinese herbal fumigation for knee osteoarthritis

“…Osteoarthritis (OA), as the most common musculoskeletal progressive disorder, leads to pain, loss of function, and decreased quality of life in elderly people. [ 1 ] Conventionally, it affects the predominant weight-bearing joints, such as the hips and knees, of which knee osteoarthritis (KOA) is the most common type. [ 2 ] It is estimated that OA affects about 1/3 people over the age of 60, with a disability rate as high as 53%.…”