Usefulness of Prone Cross-Table Lateral Radiographs in Vertebral Compression Fractures

BACKGROUND: Dynamic radiographs are recommended to investigate non-healing evidence such as the dynamic mobility or intravertebral clefts in osteoporotic vertebral compression fractures (VCFs). However, it is difficult to examine standing flexion and extension lateral radiographs due to severe pain. The use of prone cross-table lateral radiographs (PrLRs) as a diagnostic tool has never been proposed to our knowledge. The purpose of this study is to clarify the usefulness of PrLRs in diagnosis and treatment of VCFs. METHODS: We reviewed 62 VCF patients examined with PrLRs between January 1, 2008 and June 30, 2011. To compare the degree of pain provoked between standing extension lateral radiographs (StLRs) and PrLRs, numeric rating scale (NRS) scores were assessed and compared by a paired t-test. Vertebroplasty was done for 40 patients and kyphoplasty was done for 9 patients with routine manners. To assess the degree of postural reduction, vertebral wedge angles (VWA) and vertebral height ratios (VHR) were calculated by using preoperative StLRs, PrLRs, and postoperative lateral radiographs. Two variables derived from changes in VWA and VHR between preoperative and postoperative radiographs were compared by a paired t-test. RESULTS: The average NRS scores were 6.23 +/- 1.67 in StLRs and 5.18 +/- 1.47 in PrLRs. The degree of pain provocation was lower in using PrLRs than StLRs (p < 0.001). The average changes of VWA between preoperative and postoperative status were 5.24degrees +/- 6.16degrees with PrLRs and 3.46degrees +/- 3.47degrees with StLRs. The average changes of VHR were 0.248 +/- 0.178 with PrLRs and 0.148 +/- 0.161 with StLRs. The comparisons by two variables showed significant differences for both parameters (p = 0.021 and p < 0.001, respectively). The postoperative radiological status was reflected more precisely when using PrLRs than StLRs. CONCLUSIONS: In comparison with StLR, the PrLR was more accurate in predicting the degree of restoration of postoperative vertebral heights and wedge angles, and provoked less pain during examination. The PrLR could be a useful diagnostic tool to detect intravertebral cleft or intravertebral dynamic instability.

Subacute Delayed Ascending Myelopathy after Spinal Cord Injury from Flexion-distraction Injury of Low Thoracic Spine: A Case Report

STUDY DESIGN: A case report. OBJECTIVES: To report a rare case of subacute delayed ascending myelopathy. SUMMARY OF LITERATURE REVIEW: After low spinal cord injury, the cord injury may proceed to a proximal level and lead to subacute delayed ascending myelopathy. The patient suffered from orthostatic hypotension, weakness and sensory loss in the upper extremities and dyspnea. MRI showed more proximal progression of the spinal cord injury. There is no prevention or treatment for this condition. MATERIALS AND METHODS: A 62-year-old man fell from heights and had 11th thoracic spine flexion-distraction injury. Upon arrival at the hospital, he was found to suffer from lower extremity weakness and sensory loss, but showed no neurologic symptom in his upper extremities. Two days later, we performed posterior instrumentation with fusion, and no postoperative neurologic symptom change was detected. One week after the fall, he suffered from dyspnea, upper extremity weakness and sensory loss. MRI was taken and we discovered that his spinal cord injury had proceeded to the 2nd cervical spine level. RESULTS: Three months later, he showed little improvement in his upper extremity motor power, but not to the extent of the previous low spinal injury. CONCLUSION: Physicians should pay attention to the upper extremity and respiratory function of the patient with low spinal cord injury, because the level of spinal cord injury may proceed to a proximal level.