Clinical outcomes of microendoscopic decompression surgery for cervical myelopathy

Retrospective study on the results of microendoscopic decompression surgery for the treatment of cervical myelopathy. The purpose of this study was to describe the microendoscopic laminoplasty (MEL) technique as the surgical method in the treatment of cervical myelopathy, and to document the clinical outcomes for MEL surgery. Endoscopic surgery poses several challenges for the aspiring endoscopic surgeons, the most critical of which is mastering hand-eye coordination. With training in live animal and cadaver surgery, the technical progress has reduced the problem of morbidity following surgery. The authors have performed microendoscopic decompression surgery on more than 2,000 patients for lumbar spinal canal stenosis. Fifty-one patients underwent the posterior decompression surgery using microendoscopy for cervical myelopathy at authors' institute. The average age was 62.9 years. The criteria for exclusion were cervical myelopathy with tumor, trauma, severe ossification of posterior longitudinal ligament, rheumatoid arthritis, pyogenic spondylitises, destructive spondylo-arthropathies, and other combined spinal lesions. The items evaluated were neurological evaluation, recovery rates; these were calculated following examination using the Hirabayashi's method with the criteria proposed by the Japanese Orthopaedic Association scoring system (JOA score). The mean follow-up period was 20.3 months. The average of JOA score was 10.1 points at the initial examination and 13.6 points at the final follow-up. The average recovery rate was 52.5%. The recovery rate according to surgical levels was, respectively, 56.5% in one level, 46.3% in two levels and 54.1% in more than three levels. The complications were as follows: one patient sustained a pin-hole-like dura mater injury inflicted by a high-speed air-drill during surgery, one patient developed an epidural hematoma 3 days after surgery, and two patients had the C5 nerve root palsy after surgery. The epidural hematoma was removed by the microendoscopy. All two C5 palsy improved with conservative therapy, such as a neck collar. These four patients on complications have returned to work at the final follow-up. This observation suggests that the clinical outcomes of microendoscopic surgery for cervical myelopathy were excellent or showed good results. This minimally invasive technique would be helpful in choosing a surgical method for cervical myelopathy.