Detection of Covid-19 in Tissue Samples of Orthopedic Origin

Background The presence of the Covid-19 virus has been detected in tissues of various origins: nasopharyngeal swabs, sputum, bronchoalveolar fluid, blood, stool and anal swabs. However, it does not appear that the virus is excreted in the urine. The REACTing group (Research & Action Emerging Infectious Diseases) has demonstrated the presence of the virus in the conjunctiva and pleural fluid. This detection was made possible by carrying out quantitative, real-time RT-PCR and sequencing of the viral genes, which are currently the benchmark for the diagnosis of COVID-19. However, it is not known at this time whether the Covid-19 virus is present in joint fluid or in bone.

However, some viruses have a particular bone tropism (Parvovirus B19, HHV6); others have joint tropism (parvovirus B19, HBV, HCV, rubella, HIV, HTLV-1). The presence in "orthopedic" tissues of the various coronaviruses (MERS, SARS, etc.) has never been evaluated in the past. However, cases of pulmonary contamination by coronavirus after bone marrow transplantation have been reported in the literature. A potential location at these levels could cause problems of different kinds.

Rationale First, and concretely, a possible direct transmission by these tissues. The current English and Spanish national recommendations in orthopedics show a controversy as to the risk of intraoperative contamination during medical procedures generating aerosols, in particular those involving instruments at high speed (saw blade, reamer, drill). This transmission could also be a problem during bone marrow transplants, from the iliac crests, for example.

Second, but hypothetically, Covid-19 could become quiescent at the level of the myelo-hematopoietic niches and reactivate at a distance, which could then explain the current interrogation on "absence of immunity" and cases of early revival in patients considered cured. This hypothesis is all the more likely since, always by analogy with Parvovirus B19 or HHV6, a recent alert on cases of myocarditis in children has been issued in Parisian pediatric hospitals and that treatment with tocilizumab, which blocks the action Interleukin 6 receptors, and initially used for joint manifestations of rheumatoid arthritis, appear promising.