Power Doppler Assessment of the Neovascularization During Uncomplicated Fracture Healing of Long Bones in Dogs and Cats

Abstract

The aims of this prospective study were to test the feasibility of assessing neovascularization with power Doppler ultrasonography and to investigate its usefulness to follow fracture healing of long bones in dogs and cats. A total of 51 patients (44 dogs and seven cats) were followed. Fracture types differed from simple to comminuted. Therapy ranged from external coaptation to plate osteosynthesis. Patients were followed with radiography, B-mode real time and power Doppler ultrasonography every 2-4 weeks until the fracture was healed. All fractures healed uneventfully. A semi-quantitative numerical score based on signal intensity, vessel area, and number of Doppler signals was assigned and the mean value was used to compare patients and examinations. Time postoperatively was divided into periods of 10 days. No Doppler signal was present during the first 10 days. The mean of the scores was highest between 11 and 20 days postoperatively and the median of the scores peaked between 21 and 30 days. A gradual decrease was seen thereafter. The mean of the scores was zero at 71-80 days and the median at 51-0 days postoperatively for the grouped results. In all positive power Doppler examinations, signals were present in and close to the callus. In seven patients (five dogs and two cats) signals were also present in the peripheral soft tissues in one of the follow up examinations. The normal healing process of fractured bones can be visualized using power Doppler ultrasonography and follows a distinctive time-dependent pattern.

Power Doppler sonography in the assessment of neovascularization following surgical fracture repair in sheep: case report

“…New vessels have been shown to form over the course of the regenerative process, then to regress as healing progresses (RISSELADA et al, 2006). Similar events were documented in the case studied, with clear detection of new blood vessels within 14 and 21 days after surgery, which regressed progressively from day 28.…”

“…Detection of neovascularization during the bone healing process is thought to be an excellent sign (RISSELADA et al, 2006). New vessels have been shown to form over the course of the regenerative process, then to regress as healing progresses (RISSELADA et al, 2006).…”

“…The relationship between neovascularization and fracture union has been emphasized (RISSELADA et al, 2006;CHEUNG et al, 2012;). The possibility of detecting new vessel formation during the postoperative follow-up of large animals submitted to fracture repair might bring significant contributions, particularly for prognostication.…”

“…Bone vascularization is a prerequisite for proper bone healing; therefore, if blood flow cannot be restored, delayed healing or fracture nonunion may result (CHEUNG et al, 2012). Assessment of neovascularization contributes to early recognition of fracture union or nonunion (RISSELADA et al, 2006).…”

“…New vessels are known to form and then regress over the course of the fracture healing process. Power Doppler imaging is indicated to evaluate this process, given other methods, such as scintigraphy and intraosseous venography, are invasive and require general anesthesia (RISSELADA et al, 2006).…”