Study design: A multicenter, retrospective analysis of cervical epidurograms.
Objectives: To determine the effectiveness of the loss of resistance (LOR) technique in identifying the cervical epidural space. To delineate the pattern of epidural contrast spread during cervical epidural steroid injections.
Background: Previous studies have shown that if performed without fluoroscopy, the LOR technique can result in inaccurate needle placement in up to 30% of lumbar epidural steroid injections. To date, no study has examined accuracy of LOR technique and pattern of radiographic contrast spread in cervical epidural levels.
Methods: Epidurograms of 38 cervical epidural steroid injections in 31 patients were reviewed. The number of LOR attempts and pattern of contrast spread was analyzed. The effects of age, gender, MRI results, previous cervical laminectomy, and the physician's level of training were correlated with results.
Results: The authors found a 53% rate of false LOR during the first attempt to enter the epidural space. Unilateral epidural contrast spread was found in 51% and ventral epidural spread was found in 28% of cases. The average number of cervical vertebral levels covered with 2 mL of contrast was 3.14, with significantly wider spread noted in those patients who had not undergone previous cervical laminectomy. Other variables did not influence the accuracy of needle placement and pattern of epidural contrast spread.
Conclusions: The loss of resistance technique may not be an adequate method for ensuring accurate needle placement in blindly performed cervical epidural injections. The use of epidurography can improve the accuracy of needle placement and medication delivery to targeted areas of pathology.