Synthetic parathyroid hormone, supplements may help heal osteoporosis-related stress fractures

Because the long-term use of certain osteoporosis medications paradoxically increases the risk of stress fractures, researchers at the University of California, San Francisco recently investigated the potential that synthetic parathyroid hormone has for treating such injuries.

The results appeared as a case study in the Journal of Clinical Endocrinology and Metabolism. The team found that a 16-month course of the hormone-like medication, which is known as teriparatide, completely healed a pair of femoral stress fractures in a 63-year-old woman with osteoporosis.

Researchers noted that upon initial hospitalization, the patient complained of severe thigh pain, which x-rays showed to be caused by a pair of low-energy stress fractures, one in each femur.

A subsequent medical history review revealed that the woman had been taking alendronate uninterruptedly for the previous 13 years.

Also known by its U.S. brand name, Fosamax, alendronate is a prescription medication used to reverse progressive bone loss by inhibiting the action of osteoclasts, the specialized cells that break down bone minerals.

This drug is part of a class of osteoporosis medications known as bisphosphonates, which in rare cases have been known to cause femoral stress fractures as a side effect, the National Institutes of Health states.

To reverse this effect, the doctors discontinued the postmenopausal patient's use of alendronate and prescribed a 20-microgram daily injection of teriparatide. Additionally, they put the woman on large doses of vitamin D for two months, followed by a steady supplementation regimen.

After one year and four months, the patient's atypical femoral fractures had healed and her vertebral bone mass density (BMD) significantly increased.

The team noted that even though the patient's femoral BMD actually decreased over the 16-month treatment period, her bone health appeared to have improved, and she was able to walk with the assistance of a crutch.

The National Osteoporosis Foundation states that, even considering the potential for atypical femoral fractures, the positive effects of taking bisphosphonates for osteoporosis often outweigh the risks, especially among people with a high likelihood of falls and fractures.