Role of modified open-door laminoplasty in the treatment of multilevel cervical spinal stenosis: a retrospective analysis of 43 cases.

Background And Purpose: Symptomatic degenerative multilevel cervical spinal stenosis--beside other methods--is often treated using the open-door laminoplasty. This procedure aims to decompress the spinal cord and preserve the stability of the cervical spine. The efficiency and safety of the method was proved by numerous Japanese and American studies, also the technique related complications are well known. We treated 43 patients with symptomatic multilevel cervical spine stenosis using the open-door laminoplasty as a surgical procedure of choice in the National Institute of Clinical Neurosciences between 2009 and 2012. In this article we analyse our results and the related literature is discussed.

Methods: Symptomatic patients with a minimum of three-segment cervical spine stenosis and radiologically proved myelopathy or with electrophisiologically verified subclinical myelopathy were selected for laminoplasty. Patients in whom cervical kyphosis was present were operated on using laminectomy and posterior fusion. Postoperative control CT, MRI and/or X-ray images were made after the surgery and at six weeks, three, six and 12 months after the operation and in the same time neurological evaluation was performed. The modified Japanase Orthopaedic Association (mJOA) scale value was assigned to patients preoperatively, six weeks, three, six and 12 months after the operation. The statistical difference between the groups of data was tested by chi square test.

Results: The average follow-up time was 27 months (minimum seven, maximum 42). According to the mJOA scale, 26 patient's condition (61%) improved, in 13 cases (30%) remained unchanged, and in one case (2%) we detected neurological deterioration. We lost three patients during the follow up period. The median of mJOA preoperatively was 12 (minimum eight, maximum 18), while six week postoperative mJOA was 14 (minimum 10, maximum 17). Three, six and 12 months mean value of mJOA was 14 which shows that the improvement in patients' condition remained stable at one year after surgery. The difference was statistically significant (p < 0.05). The canal's average anteroposterior diameter on CT was 8.29 ± 0.92 mm at the level of C III, while after the operation we measured 15.16 ± 1.02 mm; 7.54 ± 0.62 mm at the level of C IV before, and 15.29 ± 0.2 mm after; 9.05 ± 0.48 mm at the level of C V before and 17.23 ± 0.4 mm after the surgery. The differences proved to be significant (p = 0.0001).

Conclusion: According to our experiences the modified open-door laminoplasty is an efficient and safe method for the treatment of symptomatic multilevel cervical spinal stenosis.