Clinical Observation of Cotreal - Dubousset Instrumentation in Lumbar Spine Disorders Associated with Instability

Choi, Ik Soo; Kim, Young Doo; Jeong, Jin Mo

Abstract

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 -Dubousset instrumentation as internal fixation device of spine and to analyze the causes of some complications. We analyzed 27 cases of lumbar spine disorders associated with instability which was fixed with Cotrel-Dubousset instrument form Nov. 1987 to Feb. 1989. And the minimal follow up period was 13 months. The results obtained were as follows: 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.