Despite nationwide lawsuits alleging otherwise, the United States Food and Drug Administration has found no link between oral bisphosphonates - popular medications used to treat osteoporosis - and thigh fractures.

The FDA began investigating the medications after several reports of atypical subtrochanteric femur fractures were documented in women with osteoporosis who had been prescribed oral bisphosphonates. The fractures occurred in the bone just below the hip joint - an unusual place for a break to occur, which prompted the investigation.

Bisphosphonates are a type of osteoporosis drug used to offset bone loss and prevent bone fractures in menopausal women. The following popular medications are oral bisphosphonates:

Fosamax - Merck and Co Inc.

Boniva - Roche Holding AG

Reclast - Novartis AG

Actonel - Warner Chilcott

The FDA requested information from the oral bisphosphonates manufacturers in June 2008, however, did not find an increased rick for women using the medications. Despite the clear connection between the two, the FDA is currently working with outside sources to further examine the issue.

Bisphosphonates are no stranger to controversy. In 2008, the drugs were investigated after several reports linked them to an increased risk of cardiovascular complications, although the FDA has since issued a statement stating no overall heart risks exist.

Furthermore, Fosamax side effects have been linked to several potentially life-threatening situations including osteonecrosis, or bone death of the jaw. Osteonecrosis is a slow death of bone tissue in the jaw that occurs because of poor blood supply to the bone. Side effects of ONJ include mouth swelling, loosening of teeth and exposed bone.

Merck is facing close to 900 Fosamax lawsuits from patients alleging permanent jaw damage. In January 2010, a federal judge refused to dismiss a lawsuit stating Fosamax was responsible for severe jaw damage in a woman who took the medication for close to eight years.

Merck has maintained that Fosamax has not been associated with increased fracture risks or ONJ. Ron Rogers, Merck's spokesman stated that "In clinical studies, Fosamax has not been associated with increased fracture risk at any skeletal site." Until generic versions became available, Fosamax generated close to $3 billion in sales for the company.

The FDA recommends that patients continue to take the prescribed medication unless directed otherwise by their doctor. Healthcare professionals should be aware of a "possible risk" of atypical subtrochanteric femur fractures in oral bisphosphonates patients, but the FDA has declined further action until more research has been conducted.