Anterior and Posterior Surgical Treatment with Wedged Cage (SynCage(R)) in Lumbar Degenerative Kyphosis / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: Prospective study. OBJECTIVES: Analyzing the clinical outcome of operative treatment in lumbar degenerative kyphosis (LDK) by means of anterior and posterior operation using Wedged cage (SynCage(R)) and pedicle screws. SUMMARY OF LITERATURE REVIEW LDK is common in old farmers who have worked in a stooping posture for decades and is a quite rigid form of kyphosis accompanied by adjacent instability, dystrophic changes of vertebral bodies and weakness of back and hip extensors. For surgical treatment, restoration and maintenance of lumbar lordosis is mandatory for global balance. Anterior release and restoration of disc space with the same morphologic cage seems to be a quite anatomic and harmonious approach. MATERIALS AND METHODS: Ten LDK patients, who underwent anterior interbody fusion using Wedged cage (SynCage(R)) and posterior fusion with pedicle screws between 2000 to 2001, were followed up for more than 2 years. The operation was done in one or two stages. We performed anterior release, gradual widening of the intervertebral space with wedge trials of increasing size, insertion of wedged cages filled with auto-, allo- or synthetic bone and posterior pedicle fixation and fusion. We measured the lumbar lordotic angle, sacral inclination, fusion segmental angle, thoracic kyphotic angle and vertical axis line in preoperative, immediate postoperative and follow-up standing X-ray. RESULTS: Mean fusion segments using Wedged cage were 2.8 segments for anterior interbody fusion and 3.4 segments for posterior fusion. Mean sagittal correction angle was 40.3 degrees with mean correction loss of 2.6 degrees. Whole lordosis was 6.9 degrees kyphosis preoperatively, which was corrected to 33.4 degrees lordosis postoperatively and 30.8 degrees lordosis at last follow-up. Mean sacral inclination was corrected from 18.2 degrees preoperatively to 37.8 degrees postoperatively and 30.7 degrees at follow-up. Vertical axis line was corrected from 11.4 cm preoperatively to 0.4 cm postoperatively and 1.3cm at follow-up. Thoracic lordosis was corrected spontaneously without any surgical extension to the thoracic spine by mean 19.9 degrees(0.2 degrees lordosis preoperatively to 19.7 degrees kyphosis at follow-up). Loss of cardinal signs occurred in 70-80 % of patients and satisfactory clinical results were shown in 90% of patients. CONCLUSIONS: Anterior and posterior fusion using Wedged cage (SynCage(R)) and pedicle screws showed high efficiency in the correction and maintenance of LDK. It is a good modality in the surgical treatment of lumbar degenerative kyphosis.