A 70 y.o. woman stepped off the curb and felt a sudden pain in the leg.

What medication do you need to ask her about?

Our patient had an atypical fracture caused by bisphosphonates which she was taking for osteoporosis.

The dangers of phosphorus have been known since the 19th century when workers exposed to white phosphorus in match factories developed phossy jaw.  As the disease became known; activists like Charles Dickens highlighted it in their work leading to strikes and the eventual banning of white phosphorus in factories.

But phosphorus again returned  to cause disease when it became common to use it for osteoporosis.

 Bisphosphonates are highly efficient antiresorptive drugs used to treat diseases with increased osteoclast activity such as cancer-related conditions, osteoporosis, multiple myeloma, Paget’s  disease, osteosclerosis, and fibrous dysplasia.  30 million Americans are taking bisphosphonates including Actonel, Boniva, Fosamax and Reclast.  

THE PHYSIOLOGY

Osteoporosis or  low bone density affects half of all adults aged 50 or older leaving these individuals at risk for fracture. Bisphosphonates ( and denosumab) inhibit bone resorption by preventing osteoclast creation. However, without resorption and new bone formation, the old bone survives but without  it’s capillary network. Over time, the bone becomes brittle and atypical fractures and osteonecrosis may occur.

BRONJ

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has more recently described with bisphosphonates used for osteoporosis.  While there is no good treatment for jaw necrosis from bisphosphonates; a two month long drug holiday is recommended prior to dental surgery.  Those on the drugs for more than four years,  those on steroids or getting IV bisphosphates are at greatest risk. An estimated 12% of individuals on IV bisphosphonates have jaw necrosis.

KNOWING  THE  T-SCORE

Patients may come in already knowing their T score: a predictor of fracture risk.  This  compares  the individual’s bone density to that of a healthy 30 year old.  A normal T-score would be -1.0 with osteoporosis being a T-score of -2.5. 

T-score

Isaac S. Phossy jaw and the matchgirls: a nineteenth-century industrial disease. Sept. 2018 Royal College of Surgeons of England

Devlin H. A historical review of ‘phossy jaw’ Br Dent  J 234,825-26.

Gupta M, Gupta N. Bisphosphonate related jaw osteonecrosis.July 2023.  StatPearls National Library of Medicine.

Unnanuntana A, Gladnick B, Donnelly E, Lane J. The assessment of fracture risk. J Bone Joint Surg Am. 2010 Mar;92(3):743-753.

Beninati F, Pruneti R, Ficarra G. Bisphosphonate-related osteonecrosis of the jaws. 2013 Med Oral Patol Oral Cir Bucal. May 31;18(5):e752-e758.