Clinical Significance of Magnetic Resonance Image Findings according to the Lumbar Spine Instability of Patients with Lower Back Pain

OBJECTIVE: The purpose of this study was to examine the clinical significance of magnetic resonance(MR) image findings according to the lumbar spine instability of patients with lower back pain. METHOD: Total 35 patients with lower back pain underwent lateral flexion and extension radiographs of the lumbar spine as well as MR image. The L3-4, L4-L5, and L5-S1 levels were examined. Horizontal and angular displacements in dynamic radiograph of lumbar spine were used to assess the instability of lumbar spine. MR images were used to evaluate the abnormalities of intervertebral disc, change of adjacent bone marrow, annular tear, disc herniation, and presence of osteophyte. RESULTS: Of the 105 segments, 64 (61.0%) were unstable. Among the 64 unstable segments, 28 were at the L5-S1 level and 21 were at the L4-5 level, respectively. These unstable segments showed higher degree of disc degeneration and more traction osteophyte than the stable segments. No correlation was found between segmental lumbar instability and other findings of MR image. CONCLUSION: For the assessment of lumbar spine instability, dynamic radiographs should be considered in patients with higher degree of disc degeneration or presence of traction osteophyte seen in MR image.

Clinical Observation of Cotreal / 대한정형외과학회잡지

Various kinds of spinal instrumentation have been developed for treatment of spinal disorders which are associated with instability. Recently, newly designed devices using pedicle screw were developed with advantages of short segment fixation and firm internal fixation. This is a retrospective clinical and roentgenographic study to evaluate the effectiveness of Cotrel 1. Of the 27 cases, spinal stenosis were 11, spondylolisthesis were 8, spondylolysis were 4, burst fracture were 2, metastatic bone tumor was 1, and failed back syndrome was 1 case. 2. Result of clinical evaluation by Hanley's criteria at last follow up were excellent in 7(27%), Good in 15(58% ), fair in 4(15%). (1 case of metastatic bone tumor was excluded). 3. In the cases of spondylolisthesis, we tried to reduce the displacement in 2 cases of Meyerding Grade II, and 1 case was reduced and 1 case was not reduced. In the cases of of Meyerding Grade I, no further displacement was developed. 4. The complications were observed in 10(37%)cases. A) Generalized complications were 2 cases of hematoma, 3 cases of superficial infection of wound, and 1 case of nerve root irritation. B) Failure in instrmentation were 1 case of screw breakage, 1 case of complete loss of fixation between screw and rod, and 2 cases of partial loss of fixation. 5. To prevent above mentioned complications in fixation of the instrument, the following factors are recommended: 1) Selection of the adequate length of rod. 2) Fixation of the additional implant such as security bolt when instability between screw and rod is predictable. 3) Selection of the closed head screw in the fixation of proximally sided screw if possible. 6. Cotrel-Dubousset instrument has many advantages such as rigid internal fixation, anatomical reduction, and good maintenance and also effective in reduction and maintenance of spondylolisthesis and in wide posterior decompression of spinal stenosis, but for prevention of some complications, precise use of instrument and good application of surgical technique will be needed.