Kazuhiro Maio

A prospective randomized study of clinical outcomes in patients with cervical compressive myelopathy treated with open-door or French-door laminoplasty.

Study Design. A prospective randomized clinical study. Objective. To compare the clinical outcomes of open-door and French-door laminoplasties. Summary of Background Data. Expansive laminoplasty for cervical compressive myelopathy is well established and a variety of modifications procedures have been developed. The procedures are mainly classified into open-door and French-door. It has never been prospectively investigated as to which surgical procedure, open-door or French-door laminoplasty, results in a more favorable outcome. Methods. After informed consent was obtained from 40 patients, they were randomized into 2 surgical groups A and B. Patients in group A had open-door laminoplasty, and patients in group B underwent French-door laminoplasty with reattachment of the spinous process and extensor musculatures. The following criteria were evaluated: operation time, blood loss, perioperative complications, Japanese Orthopedic Association (JOA) scores, recovery rates, axial pain, and short-form 36 (SF-36). For radiographic evaluation, cervical lordosis was reviewed as lordotic angles, which were measured at C2–C7. Results. Although the operation time was significantly less in group A as compared with group B, the mean blood loss in group A was significantly more than group B. Perioperative complications occurred more frequently in group A than in group B. Although there were no significant differences in postoperative JOA scores and recovery rates between the 2 groups, axial pain was significantly decreased in group B at final follow-up. The scores of every subscale of the SF-36 were higher in group B than group A. Conclusion. Perioperative complications occurred more frequently in open-door laminoplasty than in French-door laminoplasty. JOA scores and recovery rates suggested that both open-door and French-door laminoplasties could be similarly effective in decompressing the spinal cord. Axial pain was improved in French-door laminoplasty but became worse in open-door laminoplasty. SF-36 suggested that French-door laminoplasty could be more beneficial than open-door laminoplasty for patients with cervical compressive myelopathy.

Surgical Procedures and Clinical Results of Endoscopic Decompression for Lumbar Canal Stenosis

The purpose of this study was to evaluate the surgical indication and clinical outcomes of endoscopic decompression for lumbar spinal canal stenosis. From September 1998 to March 2002, 250 consecutive patients underwent posterior endoscopic surgery for lumbar radiculopathy. Among these patients, 27 were treated by posterior endoscopic decompression for lumbar canal stenosis. There were 19 men and 8 women, and their average age was 60 ± 12.8 years. The major preoperative symptom was neurologic claudication, sometimes accompanied by sciatica. Clinical outcomes were evaluated by the Japanese Orthopedic Association (JOA) scoring system for lumbar disease (maximum score, 29). Among the 27 patients, the average JOA score was 13.7 ± 3.8 preoperatively, which improved to 26.4 ± 2.8 postoperatively. The average operation time was 56 min for one level, and the average blood loss was 46ml for one level. There were no interoperative complications. The microendoscopic decompression technique is characterized by a small skin incision, less invasion of paraspinal muscle, and a small dead space. The ipisilateral approach and contralateral endoscopic decompression can be performed under the midline posterior structures the same as microsurgical decompression. This endoscopical decompression minimizes resection of the pathologic compression tissues and affords a safe procedure. The clinical outcome was excellent and patient satisfaction was good in most cases.

Can postoperative deltoid weakness after cervical laminoplasty be prevented by using intraoperative neurophysiological monitoring

Laminoplasty, frequently performed in patients with cervical myelopathy, is safe and provides relatively good results. However, motor palsy of the upper extremities, which occurs after decompression surgery for cervical myelopathy, often reduces muscle strength of the deltoid muscle, mainly in the C5 myotome. The aim of this study was to investigate prospectively whether postoperative deltoid weakness (DW) can be predicted by performing intraoperative neurophysiological monitoring (IONM) during cervical laminoplasty and to clarify whether it is possible to prevent palsy using IONM. We evaluated the 278 consecutive patients (175 males and 103 females) who underwent French-door cervical laminoplasty for cervical myelopathy under IONM between November 2008 and December 2016 at our hospital. IONM was performed using muscle evoked potential after electrical stimulation to the brain [Br(E)-MsEP] from the deltoid muscle. Seven patients (2.5%) developed DW after surgery (2 with acute and 5 with delayed onset). In all patients, deltoid muscle strength recovered to ≥ 4 on manual muscle testing 3–6 months after surgery. Persistent IONM alerts occurred in 2 patients with acute-onset DW. To predict the acute onset of DW, Br(E)-MsEP alerts in the deltoid muscle had both a sensitivity and specificity of 100%. The PPV of persistent Br(E)-MsEP alerts had both a sensitivity and specificity of 100% for acute-onset DW. There was no change in Br(E)-MsEP in patients with delayed-onset palsy. The incidence of deltoid palsy was relatively low. Persistent Br(E)-MsEP alerts of the deltoid muscle had a 100% sensitivity and specificity for predicting a postoperative acute deficit. IONM was unable to predict delayed-onset DW. In only 1 patient were we able to prevent postoperative DW by performing a foraminotomy.

Clinical Outcomes of Posterior Endoscopic Discectomy for Central Disc Herniation and Posterior Endplate Lesions in the Lumbar Spine

The purpose of this study was to evaluate the results and the reliability of microendoscopic discectomy (MED) on the central protruded lumbar disc. From September 1998 to December 2001, we performed MED on 200 patients (mean age, 36.3 ± 15.1 years). Among these, 28 patients who present with central disc protrusion underwent disc extraction. Central disc herniation was seen in 17 patients (mean age, 29.8 ± 8.4 years). Posterior endplate lesions were found in 11 patients (mean age, 16.8 ± 5.6 years). Evaluation of the operative results used the Japanese Orthopaedic Association (JOA) scoring sytem. Twenty-seven of 28 patients underwent endoscopic surgery. The remaining patient was a case of open conversion in which the early version of the disposable endoscope was used. The METRx reusable endoscope posed no special problems. The average JOA score of patients with central disc herniation was 12.9 ± 0.9 preoperatively, which improved to 27.8 ± 0.9 postoperatively. The average operation time was 66.5 min per segment. The average JOA score of those with endplate lesions was 17.7 ± 1.8, which improved to 27.8 ± 1.8. The average operative time was 105.9min. There were no special interoperative complications to report.

Clinical Outcomes of Microendoscopic Discectomy for Extraforaminal Lumbar Disc Herniation

The microendoscopic discectomy (MED) system for lumbar disc herniation has been developed in recent years. We applied the MED system to the treatment of extraforaminal lumbar disc herniation. The purpose of this Chapter is to present the clinical results of the MED system for cases of extraforaminal lumbar disc herniation. We performed operations using the MED system on eight patients suffering from extraforaminal lumbar disc herniation. The mean age was 57.4 years. Herniation affected discs at the L2-3 (one patient), L3-4 (one patient), L4-5 (two patients), and L5-S1 (four patients) levels. We recorded the operation time, blood loss, and time until the resumption of walking, and used the Japanese Orthopaedic Association (JOA) score for low back pain in evaluating the clinical results. The mean operation time was 90.1 min. The mean blood loss was 12.3g. All patients began to walk within 6 h postoperatively. The mean JOA score improved from a preoperative 8.2 to a postoperative 25.8. There were no complications. The MED system allows treatment of extraforaminal lumbar disc herniation with good visualization, less pain, and early return to daily activity. Our results showed that the MED system is beneficial in the treatment of extraforaminal lumbar disc herniation.