Surgical method for cervical myelopathy caused by ossification of posterior longitudinal ligament depends on cervical sagittal alignment and shape of ossification mass. For K-line (-) patients, indirect decompression method such as laminoplasty may not be effective since posterior shift of spinal cord would not occur. Therefore, other surgical method is frequently needed in this patient group. In this article, we would review surgical methods that could be applied for patients with K-line (-) cervical myelopathy caused by ossification of posterior longitudinal ligament.

Cervical ossification of posterior longitudinal ligament (OPLL) can cause cord compression which can lead to myelopathy. Operative management including anterior fusion or laminoplasty is needed in these cases. Understanding the progression course of OPLL, risk factors of progression, and risk factors of myelopathy caused by OPLL is essential to determine the necessity, timing and method of operation. Therefore, we will review the previous study results regarding characteristics and progression course of OPLL. Furthermore, the results of study about risk factors and progression course of OPLL undergoing conservative management will be discussed.

Purpose
Preoperative and postoperative trunk asymmetry were measured by 3-D full body scanner in scoliosis patients. Measured variables between operation were compared. And also compared with radiologically measured varaibles.
Materials and Methods
From february 2011 to august 2011, 20 patients with idiopathic scoliosis were treated by surgical operation. Mean age was 17.2. Using 3-D full body scanner (Medicube®), left and right side difference of weight balance, shoulder height, shoulder volume, shoulder gradient, rib hump gradient between operation were measured. Radiologically measured apical vertebra rotation (by Nash-Moe method) and 3-D scanned rib hump gradient were compared. Also radiologically measeured shoulder height (coracoid height difference) and 3-D scanned shoulder height were compared.
Results
Mean left and right side difference between operation is ; 3.2% in weight balance, 1.1% in shoulder height, 15% in shoulder volume, 3.24° in shoulder gradient, 4.72° in rib hump gradient. Differences except shoulder height were statistically significant. Rib hump gradient has the strongest significance (p-value<0.001), and improved averagely 3.4° in 15 patients. Apical vertebra rotation and rib hump gradient showed positive relation.
Conclusion
After deformity correction operation in idiopathic scoliosis patient, most of trunk measures showed significant difference, and rib hump gradient reflected apical vertebra rotation. In conclusion, 3-D full body scanner can be useful method to evaluate trunk symmetry in idiopathic scoliosis patient.