Two new studies have suggested the long-term use of oral drugs prescribed to prevent osteoporosis to be linked with unusual fractures of the thigh bone.

However, the present research is not the first of its kind to reveal a connection of the drugs, known as bisphosphonates, with unusual fractures. Other research has discovered pros and cons, with the drugs decreasing the breast cancer risk but boosting the risk of painful jaw problems.

"Bisphosphonates are a good first start," said study co-author, Dr. Melvin Rosenwasser, a professor of orthopedic surgery at Columbia University College of Physicians and Surgeons in New York City. "Used beyond a certain point, yet to be determined, they may actually be bad."

The study conducted by Rosenwasser and his colleagues is reported to involve 112 women, all past menopause, who suffered from osteoporosis.

Among the involved, 62 took osteoporosis drugs -- in this case, bisphosphonates -- for four years or more, and 50 took calcium and vitamin D supplements only.

While, the other study initiated by Dr. Joseph M. Lane from Weill Cornell Medical College in New York City, and his colleagues reported to compare bone quality in biopsies from patients who had been on bisphosphonates since a long time with those not on the drugs.