“In such cases, fractures and breaks are difficult to treat”

Medically, what is the opposite of osteoporosis, when your bones are crumbling because they are not dense enough? A condition when your bones become dense, hard, nearly stone-like. And it exists.

Patients with osteopetrosis, though a rare enough inherited condition, are being seen in orthopaedic clinics in the city.

But if the bone is hard, and dense, is that not a safeguard against breaking? “No. It’s as hard as stone. If it cracks anywhere, it shatters. In fact, osteopetrosis is called ‘marble bone’ disease,” explains S. Arumugam, orthopaedic surgeon.

There are two kinds of manifestations of the condition he goes on to add, among children and among adults. Among children, again, two possibilities exist: it starts at infancy and can be self limiting, and will vanish after a year; or, it could start in infancy and become progressively worse, and can even be fatal, he says. More cases of osteopetrosis among children are seen in clinics, compared to young adults.

“The process of bone building works this way. Osteoblasts are responsible for growth of the bone while osteoclasts take care of absorption of the old bone. Insufficient osteoclasts, or their malfunction, results in new bone building over the old one. Eventually, the medullary canal, or the marrow canal that is present in the centre of the long bone, disappears. The bone becomes a solid chunk,” Dr. Arumugam adds.

“We don’t think of bones this way, but actually bones with elasticity are less likely to break,” explains Ajit Yadav, orthopaedician, Global Hospitals. “The bones that become dense lose elasticity, become less rubbery,” he adds.

Mainly among children

“We only see children in clinics (with osteopetrosis) because they have repeated fractures. An x-ray reveals the bone without the marrow.”

In such instances, fractures and breaks are difficult to treat, says Prithvi Mohandas, director of hip replacement, MIOT Hospitals. “Especially, in case of joint replacements, where the stem of the implant usually sits smug in the canal. Here, if there is no canal, it is going to be tough to create one out of the solid bone. Also the surgery is going to take much longer than a conventional total hip replacement surgery.”

Time consuming

Dr. Arumugam actually broke some drills performing a total hip replacement on his 50-year-old patient T. Jayakumar. “If I take 45 minutes with the procedure in normal circumstance, with this patient it went on for over four hours. We had to drill a canal to place the stem of the implant. He had an old clip in place to hold together an earlier fracture,” the surgeon says. “I worked along with my assistant Sashidhar, and a team, to remove the old implant. We steadily chipped away at the stone-bone to complete the replacement procedure.”

Born with the condition, the patient and his twin brother have suffered multiple fractures throughout their life, in various bones. “Setting the bone back is a problem. While initially there was a marrow, the canal has since disappeared leaving on the dense bone. Even as children we used to be taken around to medical conferences, because of the rare condition,” Mr. Jayakumar explains. Post-surgery he says the extreme pain that he suffered at the hip has completely vanished.