New Insight into Complication of Bone Fractures

By Jane Farrell

Researchers have identified risk factors that may help orthopedic surgeons better predict a serious complication of bone fractures.

The complication, fracture nonunion, may be increasing as more patients survive serious fractures.

The investigators included Dr. Robert Zura, the Robert D’Ambrosia Professor and Head of Orthopedic Surgery at LSU Health New Orleans School of Medicine. The paper was published in the Online First section of JAMA Surgery.

To better understand the risk factors that contribute to the failure of fractured bones to heal, a national team of orthopedic surgeons examined health records from 90.1 million patients. Their goal was to describe the epidemiology of fracture nonunion in adults using the information available to physicians at patient presentation. They focused on patients 18-63 years old, representing 6,725 patients with 309,330 fractures. They researched risk factors likely to be of general concern to orthopedic surgeons and pooled data to identify 45 variables of interest.

The researchers found a nonunion rate of 4.93% overall with substantial variation from bone to bone. The lowest nonunion bone rates were in metacarpal at 1.47% and radius at 2.10%. The highest nonunion rates were in scaphoid at 15.46%, tibia and fibula at 13.95%, and femur at 13.86%.

The presence of other diseases boosted risk. Osteoarthritis, rheumatoid arthritis, and diabetes increased the odds of nonunion by at least 40%. Use of certain medications such as analgesics also upped risk. Other medications were protective. Antidiabetic medications, other than insulin, and oral contraceptives are inversely associated with nonunion.

Nonunion odds were significantly increased by many risk factors including the number of fractures, use of prescription analgesics (NSAIDs and opioids), operative treatment, open fracture, anticoagulant use, osteoarthritis with or without rheumatoid arthritis, anticonvulsant use with or without benzodiazepine, opioid use, diabetes, high-energy injury, osteoporosis, male gender, insulin use, smoking, obesity, antibiotic use, Vitamin D deficiency, diuretic use and kidney insufficiency.

The researchers contributed novel insights into the causes of fracture nonunion. They identified the most significant risk factors – the severity and location of the fracture, the presence of other diseases and medication use. This information could be used to develop a predictive algorithm.

“Understanding key risk factors and their interplay will help us determine which fractures are at greatest risk of nonunion,” Zura said. “We can alter our approach to those and modify those risk factors we can, such as prescription medicines, to improve healing.”