Magnetic resonance image findings in the early post-operative period after anterior cervical discectomy

Abstract

If early neurological deterioration occurs following anterior cervical discectomy, the patient should be evaluated by urgent MRI scanning. In order to interpret such a scan it is essential to know what the normal post-operative MRI appearance is following an uncomplicated procedure. In the lumbar spine it is well recognized that early post-operative imaging following discectomy is difficult to interpret with a high rate of false positive scans. The normal appearance of MRI in the early post-operative period was evaluated prospectively in 15 patients undergoing anterior cervical discectomy without fusion for either cervical radiculopathy or myelopathy. MRI was performed on the first post-operative day, at 6 weeks and 6 months. The successful outcome of the procedure was validated by uniform improvement of Visual Analogue Scale measurement for neck and arm pain, the Neck Disability Index and European Myelopathy Score as appropriate. In contrast to the established findings following lumbar discectomy, only two cases showed a persistent epidural mass in the first post-operative scan and this had completely resolved at 6 months. All patients had foraminal narrowing and root or cord compression pre-operatively. Sixty six percent of cases showed persistent foraminal narrowing on sequential imaging up to 6 months despite showing good symptomatic improvement. All cases demonstrated high signal in the operated disc space on T2 weighted imaging on the first post-operative day and this finding persisted in 13 of 15 scans performed at 6 weeks. Post contrast imaging demonstrated no enhancement of operated disc space and adjacent vertebral body on the first post-operative day, whereas all scans at 6 weeks showed enhancement and such enhancement persisted at 6 months in 50%. Persistent epidural filling defects are uncommon following successful anterior cervical discectomy but persistence of foraminal narrowing is common despite successful outcome. Enhancement of the disc space is also common and does not in itself imply infection.

Posterior Cervical Keyhole Foraminotomy in Treatment of Cervical Radiculopathy Following Anterior Cervical Discectomy and Fusion

“…Such technique of anterior decompression may also lead to increased residual posterior to uncovertebral junction after ACDF compared with posterior cervical keyhole foraminotomy. This finding was noticed by Bommireddy et al, 2 who reported that foraminal narrowing persisted in 66% of the first post-operative scans and did not resolve in the follow-up scans up to 6 months. Witzmann et al, 44 also emphasized the benefit of posterior cervical keyhole foraminotomy approach for removing disc fragment from lateral recess without the need for anterior cervical discectomy.…”

“…22,27,29 The outcomes following Primary ACDF for cervical disc disease have been generally excellent, with high rates of clinical improvement and minimal rates of morbidity. 17,2,28,29,31,38 Unlike primary anterior cervical surgery, revision surgery may be difficult due to scarring. 23 Fused vertebrae may interfere with disc removal and requires aggressive bone removal, distorted soft tissue and bone anatomy may lead to an overall higher morbidity and lower cure rate.…”

Rasch analysis provides new insights into the measurement properties of the neck disability index

“…The Neck Disability Index (NDI) is the most widely-used neck-specific measure in published intervention studies (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). It has been cited in over 251 scientific articles and translated into more than 20 languages (available at http:// www.cmcc.ca/Portals/0/pdfs/rs_%20NDI_manual.pdf).…”

MRI manifestations and differentiated diagnosis of postoperative spinal complications

“…During 24-48 h after operation hematoma presents low intensity or moderate intensity on T 1 WI and moderate intensity or high intensity on T 2 WI. After acute stage, lesion presents hyper-intensity on both T 1 WI and T 2 WI, and heterogeneous intensity was also observed in few cases [4,9] .…”

“…Postoperative spinal infection presents a wide array of forms such as discitis, vertebral osteomyelitis and epidural abscess [4,[9][10][11] . Clinically, severe local pain is the principal manifestation of postoperative discitis and most cases can be cured by anti-inflammation treatment.…”