Exploring the potential link between OA and infective agents
Osteoarthritis causes loss of mobility with debilitating and chronic pain. The annual cost in terms of lost work time and treatment related to the condition exceeds $185 billion per year. Despite the immense burden of the disease on society, the exact etiology of osteoarthritis remains unknown.
In recent years, numerous studies have emerged that propose a link between various disease states and infective agents. Perhaps one of the most impressive scientific discoveries related to the association between Helicobacter pylori and gastro-duodenal ulcers. Since that discovery many decades ago, evidence is emerging to link conditions, such as Alzheimer’s disease, cerebral palsy, gastric carcinoma and others, with an infective agent. The link between orthopedic conditions and an infective agent has also been proposed. The possible link between Dog-Distemper virus and Paget’s disease, Propionbacterium acnes and degenerative disc disease, and others are such examples.
Interestingly, a recent study demonstrated a direct correlation between knee osteoarthritis (OA) and dental pathogens. Studies at our institution indicate that more than 75% of primary knee surgeries show contamination by pathogens, many of which are facultative or frank anaerobes that commonly reside in the oral cavity.
We have put forth the general hypothesis that homing of oral pathogens into hypoxic joint tissues, especially those that have been subjected to trauma, triggers inflammatory cascades that promote and accelerate OA. There is an abundance of evidence that support a direct relationship between periodontal disease and orthopedic implant infections as well as septic arthritis in humans. In an animal model pilot study, we demonstrated that oral pathogens are present in stifle joint cartilage from miniature pigs with clinical signs of periodontal disease. Many of the microorganisms associated with both periodontal disease and joint infections cannot be identified using traditional culture methods. Metagenomic analysis, in particular 16S rDNA deep sequencing, is the only way to capture the full spectrum of microbes that co-exist in oral biofilms as well as identify all microbes that may be present in joint tissue and fluid.
As modern medical approaches to disease shift away from the “single causative agent” theory put towards a more complex picture of host-microbe interactions involving bacterial populations that comprise a variety of species, it is essential that the medical community embrace modern molecular methodologies for the investigation and diagnosis of diseases caused by disruption in the equilibrium of a symbiotic, healthy microbiome.
Temoin S. J. Clin. Rhematol. 2012;doi:10.1097/RHU.0b013e3182500c95.
For more information:
Thomas Schaer, VMD, can be reached at University of Pennsylvania Comparative Orthopaedic Research Laboratory, Section of Surgery, CS-NBC, 382 West Street Rd., Kennett Square, PA 19348; email: email@example.com.
Disclosures: Parvizi is a consultant to Zimmer, Smith & Nephew, 3M and Convatec. Schaer is a paid consultant for Medical Facets LLC, Biomedflex, DePuy-Synthes; an unpaid consultant for Formae, Sydney University; and receives research support from DePuy-Synthes, DuPont Actama, Musculoskeletal Transplant Foundation, Janssen Pharmaceuticals Inc., Hospital of Special Surgery, NIH, DOD, VA and has committee appointments with AO Foundation, Davos Switzerland.