Morphometric Study of the Nerve Roots Around the Lateral Mass for Posterior Foraminotomy

OBJECTIVE: Morphometric data on dorsal cervical anatomy were examined in an effort to protect the nerve root near the lateral mass during posterior foraminotomy. METHODS: Using 25 adult formalin-fixed cadaveric cervical spines, measurements were taken at the lateral mass from C3 to C7 via a total laminectomy and a medial one-half facetectomy. The morphometric relationship between the nerve roots and structures of the lateral mass was investigated. Results from both genders were compared. RESULTS: Following the total laminectomy, from C3 to C7, the mean of the vertical distance from the medial point of the facet (MPF) of the lateral mass to the axilla of the root origin was 3.2-4.7 mm. The whole length of the exposed root had a mean of 4.2-5.8 mm. Following a medial one-half facetectomy, from C3 to C7, the mean of the vertical distance to the axilla of the root origin was 2.1-3.4 mm, based on the MPF. Mean vertical distances from the MPF to the medial point of the root that crossed the inferior margin of the intervertebral disc were 1.2-2.7 mm. The mean distance of the exposed root was 8.2-9.0 mm, and the mean angle between the dura and the nerve root was significantly different between males and females, at 53.4-68.4degrees. CONCLUSION: These data will aid in reducing root injuries during posterior cervical foraminotomy.

Early Surgical Results of Minimally Invasive Posterior Foraminotomy using Tubular Retractor for Cervical Radiculopathy / 대한척추외과학회지

STUDY DESIGN: A retrospective review of the clinical and surgical outcomes in 13 patients in which minimally invasive posterior cervical foraminotomy was performed. OBJECTIVES: To report early surgical results of cervical posterior foraminotomy using a tubular retractor with minimally invasive deep muscle splitting. SUMMARY OF LITERTURE REVIEW: In previous studies of the posterior approach, good outcomes were established. The limitations of the posterior approach used to treat compression that was centrally located in the spinal canal were obvious, so the anterior approach was subsequently performed. Moreover, peri-incisional pain and discomfort related to the subperiosteal detachment of the muscle and ligament were the main limitations of this posterior approach. The use of the microendoscope allows very limited exposure with minimal tissue destruction, and has recently been used by various surgeons. MATERIALS AND METHODS: Clinical results obtained in 13 patients who underwent posterior foraminotomy from Jan 2005 through Apr 2006 were assessed using a modified Prolo outcome scale. The posterior foraminotomy was performed in a minimally invasive fashion using a tubular retractor with muscle splitting dissection. RESULTS: Eleven of 13 patients showed immediate relief of radiculopathy. Postoperative posterior cervical pain and spasm were negligible, and no surgically related complication was noted. During the follow-up period, 12 of 13 patients demonstrated a good outcome based on the modified Prolo outcome scale. CONCLUSIONS: Posterior foraminotomy using a tubular retractor is a minimally invasive surgical option for treating cervical radiculopathy and alleviating post-incisional discomfort on the neck.