Research progress on early diagnosis of nonunion of long bones

Abstract

Nonunion showed abnormal manifestations in early healing of bone fracture, which is characterized as repeated pain and radiological evidence including expansion, distraction, atrophy, induration and a visible fracture line of fracture ends. Clinically, orthopedists make a diagnosis based mostly on the healing time and bony healing standard. There is no uniform defini-tion of nonunion. The internationally recognized definition is that fracture which is at least 9 months, and no signs of healing for 3 consecutive months. Given lack of studies for early diagnosis and treatment of nonunion, most nonunion patients who have been confirmed always possess a bad prognosis. Nonunion is classified as six types among which dystrophy nonunion is the most diffi-cult type for early diagnosis based on X-ray. Besides, given its decreased callus formation, it could result in dystrophy nonunion without stress stimulus or turn into hypertrophic nonunion with the stress. Clinical assessment of early nonunion depends on utili-ties of plain radiographs, double energy X-ray, spiral CT, quantitative CT, CT image digital technique, ultrasound, radionuclide bone imaging, MRI as well as other laboratory detection, among which ultrasound and CT image digital technique showed better applications in diagnosis. For the cases of fracture internal fixation, because the fracture ends are blocked by internal fixation, the original data such as CT and MRI are usually needed to be further digitized and then the fracture healing is accurately judged. Practically, combined with the medical history and clinical manifestation, utilities of multiple clinical detection and imaging tech-niques make an effective diagnosis of nonunion, especially in determination of difficult cases.