A NOVEL TECHNIQUE FOR LAMINOPLASTY AUGMENTATION OF SPINAL-CANAL AREA USING TITANIUM MINIPLATE STABILIZATION - A COMPUTERIZED MORPHOMETRIC ANALYSIS

Study Design. Titanium miniplates are used to secure the posterior ele ments in the open position after expansive open-door laminoplasty. Pre operative and postoperative spinal can dimensions are measured to asse ss the effectiveness of this technique. Objectives. To develop a simpl e yet effective technique to stabilize the posterior elements after la minoplasty, and to compare preoperative and postoperative spinal canal dimensions to accepted normal values. Summary of Background Data. Exp ansive open-door laminoplasty has been offered as a simple alternative to laminectomy, which has been associated with postoperative kyphosis . Although the technique of laminoplasty is effective, a simple and re liable method of holding the posterior elements open has not been desc ribed. Methods. Ten myelopathic patients with multilevel cervical cana l stenosis secondary to spondylosis or ossification of the posterior l ongitudinal ligament were treated with an expansive open-door laminopl asty. The posterior elements were stabilized in the open position with titanium miniplates. Computer-assisted morphometric analysis was perf ormed on preoperative and postoperative computed tomography scans to o btain spinal canal dimensions. Plain radiographs were used to monitor construct integrity. Results. The preoperative sagittal canal diameter was 8.2 +/- 0.96 mm, and the canal area was 180.6 +/- 33.7 mm(2). The se dimensions increased after surgery to 16.6 +/- 1.5 mm and 321.9 +/- 29.7 mm(2), respectively. The titanium miniplate constructs did not f ail during the follow-up period (mean, 26.4 months), and the decompres sion was maintained. The single significant complication was a transie nt C5 radiculopathy. Conclusions. Normal canal dimensions can be reest ablished with open-door laminoplasty. Achieving and maintaining an inc reased sagittal canal diameter is probably the most important change i n anatomic parameters to facilitate neurologic recovery. The use of ti tanium miniplates to stabilize the posterior elements after laminoplas ty is a simple, durable, and effective technique to maintain the incre ased sagittal diameter of the spinal canal.