Why those who have recovered from coronavirus may face a new wave of disability

COVID-19 destroys bones

A new study by Russian scientists reveals the mechanism of one of the most severe consequences of COVID-19 — osteonecrosis, or the destruction of bone tissue, which can eventually lead to disability. The work of specialists at Sechenov University, published in the international scientific journal Pathophysiology, shows for the first time a direct link between a past infection and the rapid development of musculoskeletal disorders.

Even during the pandemic, doctors began to notice an alarming trend: among patients who had recovered from COVID-19, cases of aseptic necrosis of the femoral head began to appear on a large scale — a condition that was previously usually associated with:

• serious injuries;
• chronic alcoholism;
• prolonged use of corticosteroids.

The distinctive feature of the new cases is that the disease developed in people without traditional risk factors, sometimes even after relatively mild forms of coronavirus infection.

This led the scientific community to suggest that SARS-CoV-2 — the type 2 coronavirus strain causing severe acute respiratory syndrome (SARS) — somehow directly affects bone metabolism processes. However, the specific mechanism of this impact remained a mystery for a long time. Russian scientists were able to find the answer by conducting a large-scale comparative study of bone tissue samples from patients who had undergone hip replacement surgery.

It turned out that in patients with post-COVID osteonecrosis, the affected tissues showed an almost tenfold increase in the number of mast cells — specialized immune cells that play a key role in the development of inflammatory and allergic reactions. Their overactivation, triggered by the virus, initiates a cascade of pathological reactions that lead to impaired blood supply to the bone and its subsequent destruction.

How Tatarstan tamed coronavirus

While the mechanism of bone destruction is only beginning to be studied, Tatarstan, judging by the statistics, has handled the infection brilliantly. While scientists examined the virus’s effects at the cellular level, the republic went through all stages of the pandemic — from the initial shock to full stabilisation.

The dynamics of coronavirus spread in the republic from March 2020 to March 2025 demonstrated the classic progression from the acute phase of the pandemic to a stable endemic situation.

2020: the beginning of the pandemic
In the first year of the pandemic, 13.4 thousand cases of infection were registered, with 186 deaths and 13.2 thousand recoveries. The peak number of active cases reached 1,296 in May, while the healthcare system quickly adapted to the new challenges.

2021: rise in morbidity
The year showed a significant increase — 161.3 thousand new cases, 1,824 deaths, and 159.5 thousand recoveries. The winter peak of 2021–2022 reached 17 thousand active cases, yet the death toll remained relatively low thanks to accumulated treatment experience and the beginning of vaccination.

2022: stabilisation
67.7 thousand new infections were recorded, mortality dropped to 0 cases for the year, and 67.7 thousand people recovered. Seasonal surges became less pronounced (peaks did not exceed 7–8 thousand active cases), and the transition to an endemic mode began.

2023: decline in morbidity
The indicators continued to improve: 23.8 thousand new cases, 0 deaths, and 23.8 thousand recoveries. The situation shifted to a controlled endemic phase with seasonal fluctuations of 500–1,000 active cases.

2024–2025: endemic period

Over the past year, only 175 new cases were registered, with no deaths and a 100% recovery rate. Current figures as of March 2025 (150–260 active cases) confirm that COVID-19 in Tatarstan has moved into the category of controlled infections.

Over the five years, the republic recorded approximately 242 thousand infections, 2,010 deaths, and 240 thousand recoveries, reflecting the high efficiency of the medical system — 99.1% of patients successfully overcame the disease.

Currently, the COVID-19 situation in Tatarstan is under control and fully falls within the framework of seasonal morbidity. Regional Rospotrebnadzor told Realnoe Vremya that the number of infections is declining: 297 cases were recorded last week, more than 15.9% fewer than the previous week. The total monthly statistics (around 1,000 cases) confirm that there is no surge in infections. The main circulating variant among the population remains Omicron.

“Currently, there are many post-COVID patients”

Albert Rizvanov, head of the Center of Excellence for “Personalized Medicine” at Kazan Federal University, confirmed scientists’ concerns about a new post-COVID complication. Commenting on the recent study by colleagues at Sechenov University, he explained the identified mechanism of bone tissue damage.

Rizvanov emphasized that the study by Sechenov University adds “morphological confirmation specifically in bone tissue” to the already known data on the effects of coronavirus on the body. He also drew a parallel with other serious infections, noting that any acute illness, whether COVID-19 or influenza, disrupts the body’s balance for a prolonged period.

In addition to the bone tissue damage described in the study, a past COVID-19 infection can have many other serious consequences affecting medical protocols, according to anesthesiologist and resuscitation specialist Ruslan Artemyev.

The expert highlighted key areas where the effects of the virus are most pronounced:

• Neurological and psychiatric complications: Increased anxiety, frequent stressful situations leading to the use of antidepressants. In severe cases — post-COVID meningoencephalitis affecting the central and peripheral nervous systems, which can manifest as motor disorders, vision and hearing problems, emotional and behavioral disorders, and even cerebrovascular impairments. A separate hypochondriacal variant of the syndrome is noted, in which a person lives in constant fear of death, worsening their condition.
• Systemic vasculitis and thromboses: Post-COVID vasculitis of micro— and macrovessels manifests as various skin rashes, mottling, Raynaud’s syndrome, and hair loss. The main danger is thrombo-vasculitis, leading to thromboembolic complications in various organs.
• Multiple organ failure: Secondary changes affect almost all systems: pulmonary, renal, hepatic, as well as consequences of deep vein thrombosis.
• General debilitating symptoms: Chronic fatigue preventing daily activities, impaired thermoregulation, chills, and excessive sweating.

Artemyev also emphasized the post-COVID syndrome that develops during or after COVID-19 infection.