Author: Zura R1, Mehta S, Rocca GJ, Jones J, Steen RG.
Affiliation: 1Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA, Robert.Zura@duke.edu.
Conference/Journal: BMC Musculoskelet Disord.
Date published: 2015 Dec
Other: Volume ID: 16 , Issue ID: 1 , Pages: 498 , Special Notes: doi: 10.1186/s12891-015-0498-1. , Word Count: 331
Patient age is one of many potential risk factors for fracture nonunion. Our hypothesis is that older patients (≥60) with fracture risk factors treated with low-intensity pulsed ultrasound (LIPUS) have similar heal rate (HR) to the population as a whole. We evaluate the impact of age in conjunction with other risk factors on HR in LIPUS-treated patients with fresh fracture (≤90 days old).
The Exogen Bone Healing System is a LIPUS device approved in 1994 to accelerate healing of fresh fracture. After approval, the FDA required a Post-Market Registry to assess performance. Patient data collected from October 1994 until October 1998 were individually reviewed and validated by a registered nurse. Four distinct data elements were required to report a patient: date fracture occurred; date treatment began; date treatment ended; and a dichotomous outcome of healed v. failed, by clinical and radiological criteria. Data were used to calculate two derived variables; days to treatment (DTT) and days on treatment (DOT). Every validated fresh fracture patient with DTT, DOT, and outcome is reported.
The validated registry had 5,765 patients with fresh fracture; 73% (N = 4,190) are reported, while 13% of patients were lost to follow-up, 11% withdrew or were non-compliant, and 3% died or are missing outcome. Among treatment-compliant patients, HR was 96.2%. Logistic estimates of the odds ratio for healing are equivalent for patients age 30 to 79 years and all age cohorts had a HR > 94%. Open fracture, current smoking, diabetes, vascular insufficiency, osteoporosis, cancer, rheumatoid arthritis, and prescription NSAIDs all reduced HR, but older patients (≥60) had similar HRs to the population as a whole. DTT was significantly shorter for patients who healed (p < 0.0001).
Comorbid conditions in conjunction with aging can reduce fracture HR. Patients with fracture who used LIPUS had a 96% HR, whereas the expected HR averages 93%. Time to treatment was significantly shorter among patients who healed (p < 0.0001), suggesting that it is beneficial to begin LIPUS treatment early. Older patients (≥60) with fracture risk factors treated with LIPUS exhibit similar heal rates to the population as a whole.