Microsurgical posterior herniotomy with en bloc laminoplasty: alternative method for treating cervical disc herniation.

Objective: At the present time, the anterior cervical discectomy and fusion procedure is widely accepted for treating cervical disc herniation. Recently, however, several authors have reported new disease due to degeneration of an adjacent segment. On the other hand, posterior discectomy, which can preserve mobility at the affected disc level, has been considered risky and technically difficult, especially for central or paracentral disc herniation. We are performing a new surgical technique, microsurgical posterior herniotomy with en bloc laminoplasty, for patients with myelopathy and radiculomyelopathy caused by cervical disc herniation. Methods: Here, the surgical outcomes and radiographic changes were retrospectively investigated. Thirty patients (13 patients with myelopathy, 13 patients with radiculomyelopathy, and 4 patients with C5 dissociated motor loss) who underwent this procedure were reviewed. The average age was 50 years (range 31-70 years), and the average follow-up period was 28 months (range 12-76 months). Neurologic improvements were evaluated using the Japanese Orthopaedic Association (JOA) Scoring System as well as radicular pain and deltoid muscle power. Postoperative axial symptoms were scored, and radiographic changes were noted. Results: The mean JOA score improvement was 74.2% (range 27.3-100%). In all 13 patients, preoperative radicular pain completely resolved after surgery. Deltoid power (in cases of C5 dissociated motor loss) markedly increased postoperatively. Cervical lordosis significantly increased at the time of the last follow-up (P = 0.01). The postoperative axial symptom score significantly correlated with the numbers of opened laminae (P = 0.03). Conclusions: This technique was safe and effective. Radiographically, the range of motion in the cervical spine and at the affected disc levels was preserved. In the future, this surgical procedure can become an alternative method for cervical disc herniation treatment.