SAN DIEGO — Heel ultrasound is a promising way to initially identify low bone mass in developmentally disabled patients, Dr. Kelly D. Krohn said during a poster session at the annual meeting of the International Society for Clinical Densitometry.
The finding is important because low bone density “is a common, complicated problem in people who have physical disabilities,” Dr. Krohn, director of clinical research, department of medicine, at Mercy Hospital in Pittsburgh, Pa., said in an interview. “A big part of it is that they're not able to bear weight. They're sitting in a wheelchair for 25–30 years and they have really fragile bones. But they're also challenging to bring to the office and do standard DXA [dual-energy x-ray absorptiometry] bone density testing on.”
He and his associates used a portable heel ultrasound densitometer to screen 135 mentally and physically challenged men and women who were living in intermediate care facilities in Allegheny County, Pa. Screenings took place either in their residence or at the hospital's on-site medical clinic.
The researchers, who were led by Dr. Vinee Varma, also of Mercy Hospital, collected data on age, gender, race, and weight-bearing status.
They defined low bone mass as having a T score of −1.0 or lower.
If heel scans were positive, the researchers forwarded the results to the physician.
When indicated, patients were referred for a central DXA of the hip and spine.
The average age of the 135 patients was 50; about half (68) were men; and most (90%) were white.
Of the patients, 55% had full weight-bearing capabilities, 42% were unable to bear weight, and 3% were able to partially bear weight.
Dr. Krohn and his associates found that 80% of the women and 72% of the men had evidence of low bone density on heel ultrasound. In addition, 91% of patients who were unable to bear weight had low bone mass, compared with 70% of patients who had full weight-bearing capabilities.
Subsequent central DXA scans performed in 91 patients confirmed the overall results of the positive heel ultrasounds. When the researchers used a heel ultrasound T score of −1.0 or lower, 70% had low bone mineral density (BMD) on central DXA. When they used a heel ultrasound score of −2.0 or lower, 81% had low BMD on central DXA.
In another component of the study, five patients with a normal heel ultrasound had central DXA performed. Low BMD was found in two of the five.
“Any screening test has failures,” Dr. Krohn noted.
“You miss some and you overcall some. For us, heel ultrasound has been a nice way to get a good handle on [the BMD in] several hundred disabled residents. A large number of them have a real risk for fractures. This is an easy way to identify them,” he said.
'Heel ultrasound has been a nice way to get a good handle on [BMD in] several hundred disabled residents.' DR. KROHN