Application of MPR in sacral nerve injury during sacral fracture.

Background: To investigate the diagnostic and clinical value of multiplanar reconstruction (MPR) with spiral computed tomography for sacral nerve injury during sacral fracture. Methods: From April 2007 to April 2009, 10 patients with sacral nerve injury during sacral fracture admitted to the Affiliated Shenjing Hospital of China Medical University were included in this study; of these, seven were men and three were women, aged around 30 years to 55 years. Hospital admission time from injury was around 1 day to 30 days for these patients. Causes of injury included six cases of car crashes, three cases of fallen heavy objects, and one case of crush injury. To evaluate fracture status of the sacral neuroforamen and relative position of fractured bone to the root of nerve, entire neuroforamen of sacral nerve was observed by MPR technique at double-oblique position (45-degree oblique coronary position and 30-degree oblique sagittal position), under which the fracture condition of sacral neuroforamen could be clearly displayed for further clinical verification. Results: According to the 1990 standard classification for spinal injury by the National Spinal Cord Injury Association and the International Spinal Cord Society, with consideration of the clinical manifestations, clinical diagnosis of all patients were as follows: six cases of injury to S1 root, two cases of injury to S2 root, two cases of injury to both S1 and S2 roots, three cases of penetration of S1 neuroforamen by fractured bone after MPR at double-oblique position, one case of injury to S2 neuroforamen, and two cases of penetration of both S1 and S2 neuroforamen by fractured bone. Diagnosis of last six patients was confirmed by surgery (observed compression of S1 and S2 nerves by fractured bones). In addition, after removal of compression causes, symptoms of the patients were significantly improved, and patients completely recovered in an average of 12 weeks. After the MPR examination at double-oblique position, the remaining four patients (3 cases of injury to S1 and 1 case of injury to S2) did not show penetration of fractured bones to neuroforamen (thus considering the diagnosis of simple neural contusion). These patients recovered well after an average of 13-week conservative therapy. Conclusion: Sacral MPR at double-oblique position can be used as a routine examination for patient with sacral fracture, which is of great significance in determining the cause of injury to sacral nerve. Furthermore, it can also provide radiologic evidences to analyze the need for surgical therapy.