Anterior Cervical Microforaminotomy / 한양의대학술지

Anterior cervical microforaminotomy is the one of surgical options for treating cervical spondylotic lesions manifested by radiculopathy or myelopathy. This minimally invasive surgical procedure is gaining popularity due to the recent trends of avoidance of spinal fusion resulting in loss of the physiologic spinal motion and developing a future adjacent segment syndrome. Although the spinal fusion still remains a gold standard procedure for degenerative cervical spinal diseases, the eager for maintaining the function of the motion segment is another issue for contemporary spinal surgeons. Anterior cervical microforaminotomy is a target-oriented operation that decompresses the nerve root or spinal cord without destruction of the spinal anatomical functional unit. Unlike to other procedures including total or partial resection of the intervertebral disc, this surgical procedure removes only a small part of the uncovertebral joint or vertebral body. Through this narrow corridor, adequate decompression of the nerve root or spinal cord can be achieved while preserving functional motion. Technical variations of the original anterior cervical microforaminotomy have been continuously developed to minimize the concerns for the postoperative disc height loss and instability. As of now, the anterior cervical microforaminotomy and its technical variations have been proved to be an excellent procedure for treating the cervical spondylotic radiculopathy from literatures review. But the long-term clinical results and the efficacy of the procedure for cervical myelopathy still remain to be seen.

Morphometric Measurement of the Anatomical Landmark in Anterior Cervical Microforaminotomy

OBJECTIVE: The lack of anatomical knowledge for the anterior cervical microforaminotomy is liable to injure the neurovascular structures. The surgical anatomy is examined with special attention to the ventral aspect exposed in anterior cervical microforaminotomy. METHODS: In 16 adult formalin fixed cadaveric cervical spine, the author measured the distances from the medical margin of the longus colli to the medical wall of the ipsilateral vertebral artery and the angle for the ipsilateral vertebral artery. The distances from the lateral margin of the posterior longitudinal ligament to the medial margin of the ipsilateral medial wall of the vertebral artery, to the ipsilateral dorsal root ganglion was measured too. RESULTS: The distance from the medial margin of the longus colli to the ipsilateral vertebral artery was 13.3~14.7mm and the angle for the ipsilateral vertebral artery was 41~42.5 degrees. The range of distance from the lateral margin of the posterior longitudinal ligament to the ipsilateral vertebral artery was 11.9~16.1mm, to the ipsilateral dorsal root ganglion was 11.6~12.9mm. CONCLUSION: These data will aid in reducing neurovascular injury during anterior cervical approaches.

Midterm Follow-up Results of Anterior Cervical Microforaminotomy

OBJECTIVE: We have previously reported excellent early clinical results of anterior cervical microforaminotomy(ACMF) for patients who have cervical radiculopathy from either disc herniation or foraminal stenosis. ACMF is being accepted as a minimal invasive functional spinal surgery, but their long-term outcome is unknown. The goal of this study is to evaluate the midterm clinical and radiological results of ACMF. METHODS: We had undertaken a questionnaire survey and retrospective analysis of 42 patients with cervical radiculopathy who had undergone ACMF from 1998 to 2001. Clinical data from 33 patients(one-level operation in 20 patients, two-level in 13 patients) and radiological data from 21 patients were analysed. RESULTS: Thirty-three patients answered for the questionnaires. Mean follow-up was 48 months(ranged from 26 to 64 months). The surgical outcome was excellent in 18 patients(54.6%) and good in 11 patients(33.3%). One patient showed poor outcome, but there was no case of recurrence, reoperation or additive surgery. Twenty-four patients(79%) satisfied with the results of their surgery. On the average, the loss of disc height was 1.02mm(18% of preoperative disc height), average increase of displacement was 0.83mm, decrease of sagittal plane angulation was 2.03 degrees. All the patients maintained stability during follow-up period. CONCLUSION: In the midterm, ACMF appears to be safe and effective method for the treatment of cervical radiculopathy. To prevent disc height loss and retrolisthesis, skilled disc-preserving technique of ACMF is required and modified technique preserving anterior part of uncovertebral joint may be advantageous.