KOLKATA: Avascular necrosis, a debilitating disease that causes bone degeneration, has struck a few patients in Kolkata who had recovered from Covid several months ago, raising concern among experts about the deferred impact of the virus which could be fatal.
At least three such patients have been treated at a private hospital in the city over the last few months, including one who is now admitted and is set to undergo a hip-replacement surgery. A section of doctors suspect it could be the result of steroids taken on a long-term basis by the patients during Covid treatment.
The disease, also known as AvN, leads to bone degeneration and eventually a complete fracture and collapse of the affected bones. It is triggered by clotting of the small blood vessels in the bone that get blocked due to Covid, resulting in lack of blood and oxygen supply to the bone. It results in ‘bone death’ and replacement surgery is the only viable treatment option.
Other than a 40-year-old now being treated at Belle Vue Clinic, another patient had been admitted just prior to the onset of the second wave in April. Doctors are surprised at the late onset of the disorder in the patients, both of whom had Covid prior to May 2020.
“I have a patient admitted who had Covid about a year ago. Three months ago, I treated another patient who had Covid back in April, 2020,” said Belle Vue Clinic internal medicine consultant Rahul Jain. He added that both were administered steroids during their Covid treatment, which may have aggravated their condition. “But they had a perfect recovery form Covid and returned to work without symptoms till they started having excruciating pain in their affected bones. By the time they sought treatment, blood vessels around them had clogged completely and the bones had degenerated irretrievably,” said Jain.
The Belle Vue patient is set to undergo a hip replacement surgery. In the previous case, too, the patient underwent the same procedure.
AvN mostly strikes the hip bone, according to CMRI Hospital director of pulmonology Raja Dhar. “It is most likely the result of long-term steroid use rather than Covid itself. Patients suffering lung fibrosis during Covid often require long-term steroids which exposes them to the risk of AvN. It is an unusual after-effect of Covid, unlike a brain stroke or a cardiac arrest, which are triggered by Covid-induced coagulation of blood vessels,” said Dhar.
He added that though AvN cases are very few and usually the disease strikes late. “Initial symptoms could be a limp, sudden shrinkage of a limb, usually one of the legs. In later stages, pain worsens since the bone starts crumbling,” added Dhar.
Jain agreed and pointed out that his patient has a similar history. “He is a technician who has to handle heavy machinery and had no issues with muscles or bones till he had Covid,” said Jain, adding that short-term use of steroids, ranging between 5-10 days should not trigger AvN.
Patients are prescribed non-steroidal anti-inflammatory drugs and asked to take complete rest and desist from lifting weights. Bone transplant (graft), bone reshaping or joint replacement are the treatment options.
Long-term use of steroids may lead to a rise in lipid levels, triggering flat globules in the bone joint arteries leaving them blocked, said Belle Vue consultant orthopaedic surgeon Hassan Iqbal. “Other than trauma, the most common reason behind a femur head fracture is the consistent use of steroids. There is yet no evidence to establish a direct co-relation with Covid, but steroids do play a part,” said Iqbal.