Epidemiology of Fracture Nonunion in 18 Human Bones.
Failure of bone fracture healing occurs in 5% to 10% of all patients. Nonunion risk is associated with the severity of injury and with the surgical treatment technique, yet progression to nonunion is not fully explained by these risk factors.



To test a hypothesis that fracture characteristics and patient-related risk factors assessable by the clinician at patient presentation can indicate the probability of fracture nonunion.



An inception cohort study in a large payer database of patients with fracture in the United States was conducted using patient-level health claims for medical and drug expenses compiled for approximately 90.1 million patients in calendar year 2011. The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology codes; comorbidities as per International Classification of Diseases, Ninth Revision codes; and drug prescriptions as per National Drug Code Directory codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion. Data analysis was performed from January 1, 2011, to December 31, 2012.



Continuous enrollment in the database was required for 12 months after fracture to allow sufficient time to capture a nonunion diagnosis.



The final analysis of 309 330 fractures in 18 bones included 178 952 women (57.9%); mean (SD) age was 44.48 (13.68) years. The nonunion rate was 4.9%. Elevated nonunion risk was associated with severe fracture (eg, open fracture, multiple fractures), high body mass index, smoking, and alcoholism. Women experienced more fractures, but men were more prone to nonunion. The nonunion rate also varied with fracture location: scaphoid, tibia plus fibula, and femur were most likely to be nonunion. The ORs for nonunion fractures were significantly increased for risk factors, including number of fractures (OR, 2.65; 95% CI, 2.34-2.99), use of nonsteroidal anti-inflammatory drugs plus opioids (OR, 1.84; 95% CI, 1.73-1.95), operative treatment (OR, 1.78; 95% CI, 1.69-1.86), open fracture (OR, 1.66; 95% CI, 1.55-1.77), anticoagulant use (OR, 1.58; 95% CI, 1.51-1.66), osteoarthritis with rheumatoid arthritis (OR, 1.58; 95% CI, 1.38-1.82), anticonvulsant use with benzodiazepines (OR, 1.49; 95% CI, 1.36-1.62), opioid use (OR, 1.43; 95% CI, 1.34-1.52), diabetes (OR, 1.40; 95% CI, 1.21-1.61), high-energy injury (OR, 1.38; 95% CI, 1.27-1.49), anticonvulsant use (OR, 1.37; 95% CI, 1.31-1.43), osteoporosis (OR, 1.24; 95% CI, 1.14-1.34), male gender (OR, 1.21; 95% CI, 1.16-1.25), insulin use (OR, 1.21; 95% CI, 1.10-1.31), smoking (OR, 1.20; 95% CI, 1.14-1.26), benzodiazepine use (OR, 1.20; 95% CI, 1.10-1.31), obesity (OR, 1.19; 95% CI, 1.12-1.25), antibiotic use (OR, 1.17; 95% CI, 1.13-1.21), osteoporosis medication use (OR, 1.17; 95% CI, 1.08-1.26), vitamin D deficiency (OR, 1.14; 95% CI, 1.05-1.22), diuretic use (OR, 1.13; 95% CI, 1.07-1.18), and renal insufficiency (OR, 1.11; 95% CI, 1.04-1.17) (multivariate P < .001 for all).



The probability of fracture nonunion can be based on patient-specific risk factors at presentation. Risk of nonunion is a function of fracture severity, fracture location, disease comorbidity, and medication use.
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Robert
R
Zura
Department of Statistics, North Carolina State University, Raleigh.
Ze
Z
Xiong
Department of Orthopaedic Surgery, New York University Langone Medical Center, New York.
Thomas
T
Einhorn
Department of Orthopaedic Surgery, Saint Louis University School of Medicine, St. Louis, Missouri.
J Tracy
JT
Watson
Department of Orthopaedic Surgery, University of North Carolina, Chapel Hill.
Robert F
RF
Ostrum
Department of Orthopaedics and Sports Medicine, Wright State University, Dayton, Ohio.
Michael J
MJ
Prayson
Department of Orthopaedic Surgery, University of Missouri, Columbia.
Gregory J
GJ
Della Rocca
Department of Orthopaedic Surgery, Hospital of the University of Pennsylvania, Philadelphia.
Samir
S
Mehta
Department of Orthoapaedic Surgery, Indiana University, Indianapolis.
Todd
T
McKinley
Department of Statistics, North Carolina State University, Raleigh.
Zhe
Z
Wang
Medical Affairs, Bioventus LLC, Durham, North Carolina.
R Grant
RG
Steen
D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D000927:Anticonvulsants / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000453:epidemiology*; D001842:Bone and Bones / Q000293:injuries* / Q000601:surgery; D015897:Comorbidity; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology*; D005260:Female; D005269:Femur / Q000293:injuries; D005360:Fibula / Q000293:injuries; D005500:Follow-Up Studies; D017102:Fracture Healing; D005599:Fractures, Ununited / Q000145:classification / Q000453:epidemiology* / Q000601:surgery; D006801:Humans; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D010003:Osteoarthritis / Q000453:epidemiology*; D065840:Protective Factors; D051437:Renal Insufficiency / Q000453:epidemiology; D012307:Risk Factors; D021361:Scaphoid Bone / Q000293:injuries; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D013978:Tibial Fractures / Q000453:epidemiology; D015599:Trauma Severity Indices; D014808:Vitamin D Deficiency / Q000453:epidemiology; D055815:Young Adult
D000701:Analgesics, Opioid; D000900:Anti-Bacterial Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000925:Anticoagulants; D000927:Anticonvulsants; D007328:Insulin