Reliability Of Imaging In The Assessment Of Injuries Of The Soft Tissue In Hyperextension Injury Of Cervical Spine

Hyperextension injuries of the cervical spine constitute 25-50% of all severe traumatic cervical cord injuries. Hyperextension injury of cervical spine can result in the severe injuries of the anterior longitudinal ligament(ALL) and disc which contribute to spinal stability .The purpose of this study was to assess the reliability of diagnosis for injuries of the soft tissue in hyperextension injury of cervical spine using magnetic resonance imaging(MRI)and X-ray examination,also to evaluate the clinical value of intraoperative cervical discography for injuries of the soft tissue in hyperextension injury of cervical spine.The study consisted of twenty patients of hyperextension injury of cervical spine (10 male and 2female, range 36-59 years ,mean age 48.6 years)were undergone anterior approach operation or anterior and posterior contemporary approach operation from August 2007 to December 2008.The injuries were caused by traffic accident for 7 cases which accounting for 58.3 percent of all cases, falling for 4 cases(33.3%), slipping for 1 case(8.3%).Twenty patients undergoing magnetic resonance imaging , anteroposterior and lateral X-ray examination .The criteria of X-ray examination of soft tissue injuries is widened intervertebral space .The discontinuity of spinal ligaments before adjacent vertebral space appear as black stripes on MRI suggested as a sign of ALL rupture . Disc injury on MRI showed that signal changes such as T2WI high signal or mixed signal, morphological changes such as blurred nucleus, adjacent vertebral space changes or disc herniation . The imaging of 12 patients were assessed independently by one consultant radiologists and one spinal surgeon who didn't take part in a clinical diagnosis and treatment of patients. Interobserver correlation for each assessment was determined using the kappa statistic. Seven cases of all were undergone anterior approach operation ,five cases were undergone anterior and posterior contemporary approach operation. During the anterior approach operation, disc and anterior longitudinal ligament injuries were examined and recorded,also intraoperative cervical discography were done in four cases. The result of operations research in disc and anterior longitudinal ligament, which was diagnosed by one spinal operator and one spinal assistant, suggested as the diagnosis standard of disc and anterior longitudinal ligament injuries. Rupture of anterior longitudinal ligament means its injury, disc injury showed rupture of annulus or disc rupture.The result of ALL injuries on X-ray examination: The injuries of soft tissue at 17 of 72 disc levels(23.6%)by Observer 1,and the injuries of soft tissue at 20 of 72 disc levels(27.8%)by Observer 2. Interobserver consistency of the signal changes for the assessment of soft tissue injuries was substantial (Kappa value=0.715). The result of ALL injuries on MRI: The rupture of ALL at 24 of 72 disc levels(33.3%)on T1WI and at 17 of 72 disc levels(23.6%)on T2WI by Observer 1.The rupture of ALL at 29 of 72 disc level(s40.3%)on T1WI and at 19 of 72 disc levels(26.4%)on T2WI by Observer . Interobserver consistency of T1WI and T2WI for the assessment of ALL injury was substantial (Kappa value=0.733, 0.630)。The result of disc injuries on MRI:The signal changes of disc at 21 of 72 disc levels(29.2%)on MRI and the morphological changes of disc at 18 of 72 disc levels(25%)on MRI by Observer 1.The signal changes of disc at 26 of 72 disc levels(36.1%)on MRI and the morphological changes of disc at 20 of 72 disc levels(27.8%)on MRI by Observer 1. Interobserver consistency of the signal changes for the assessment of disc injury was substantial (Kappa value=0.654),Interobserver consistency of the morphological changes for the assessment of disc injury was almost perfect (Kappa value=0.857). The result of operations research :The result of operations research showed 12 case with haematoma and oedema at the anterior of the vertebral body. The result also showed 17 disc levels (47.2%) with ALL injuries and 14 disc levels(38.9%) with disc injuries. One disc level(2.8%) appeared with posterior longitudinal ligament injury. The distribution of ALL injuries from the C2-3 to C7-T1 were : 0 disc level,1 disc level,4 disc levels,8 disc levels,4 disc levels and 0 disc level. The distribution of disc injuries from the C2-3 to C7-T1 were : 0 disc level,1 disc level,4 disc levels,6 disc levels,3disc levels and 1 disc level .In the 12 cases, the result of operations research were detection of 36 disc levels which compared With the preoperative diagnosis of MRI and X-ray examination on the corresponding disc levels.To assess the reliability of diagnosis for the soft tissue injuries in hyperextension injury of cervical spine using MRI and X-ray examination .The reliability of diagnosis for the soft tissue injuries in hyperextension injury of cervical spine using X-ray examination : The sensitivity was 35.3%,41.2%;specificity:47.4%,42.1%; and accuracy:41.7%,41.7%,positive predictive value:41.7%,41.7%;negative predictive value:45.0%,44.4% by Observer1 and Observer2. Interobserver consistency of X-ray examination for the assessment of soft tissue injuries was substantial (Kappa value= 0.664).The reliability of diagnosis for ALL injuries in hyperextension injury of cervical spine using MRI : The sensitivity of T1WI and T2WI in ALL injuries was 76.5%,70.6%;specificity: 68.4%,63.2%; and accuracy:72.2%,72.2%,positive predictive value:68.4%,63.2%;negative predictive value:76.5%,71.4% by Observer1.The sensitivity of T1WI and T2WI in ALL injuries was 64.7%,58.8%;specificity:78.9%,73.7%; and accuracy:72.2%,66.7%;positive predictive value:73.3%,66.7%;negative predictive value:71.4%,66.7% by Observer 2.Interobserver consistency of T1WI for the assessment of ALL injury was substantial (Kappa value=0.719). Interobserver consistency of T2WI for the assessment of ALL injury was moderate (Kappa value=0.543).The reliability of diagnosis for disc injuries in hyperextension injury of cervical spine using MRI :The sensitivity of The signal changes of disc and the morphological changes of disc in disc injuries was 28.6%,64.3%;specificity, 59.1%,81.8%; and accuracy, 47.2%,75.0%;positive predictive value,30.8%,69.2%;negative predictive value,56.5%,78.3% by Observer1.The sensitivity of The signal changes of disc and the morphological changes of disc in disc injuries was 46.7%,57.1%;specificity, 45.5%,77.3%;and accuracy, 45.9%,69.4%;positive predictive value,36.8%,61.5%;negative predictive value,55.5%,73.9% by Observer2. Interobserver consistency of the signal changes for the assessment of disc injury was substantial (Kappa value= 0.618), Interobserver consistency of the morphological changes for the assessment of disc injury was almost perfect (Kappa value= 0.869).The result of diagnosis for 4 disc injuries and 4 disc level ALL injuries in 4 case of 12 case hyperextension injury of cervical spine using intraoperative cervical discography,which was the same as the result of operations research.Intraoperative cervical discography is effective and supplemental method of evaluating the injuries of the soft tissue in hyperextension injury of cervical spine. Discontinuity of the"black stripe"in T1WI or T2WI is unreliable in assessing the injuries of the ALL in hyperextension injury of cervical spine , T1WI is reliable than T2WI . Signal changes or morphological changes of the cervical disc in MRI are unreliable in assessing the injuries of the disc in hyperextension injury of cervical spine , morphological changes are reliable than signal changes . X-ray examination (widened intervertebral space) is unreliable in assessing the injuries of the soft tissue in hyperextension injury of cervical spine .