Clinical and radiological comparison of cases WHO underwent short segment lomber stabilization using peek rod and rigid rod systems

Introduction: This study evaluates the second-year preoperative and postoperative clinical and radiological results of 54 patients with lumbar degenerative disc disease who underwent Level-III lumbar transpedicular stabilization operation where PEEK rods and rigid rods were used between March 2017 and June 2018 in the Neurosurgery Clinic of Akdeniz University, Medical Faculty Hospital. Purpose: The purpose of this study is to compare PEEK rods and rigid rods in patients with lumbar degenerative disc disease who underwent Level-III lumbar transpedicular stabilization in terms of the development of adjacent segment disease and pseudoarthrosis radiologically and to compare the re-operate rates and the second-year ODI and VAS score changes of the two groups. Material and Method: 54 patients included in this study were mainly divided into two groups, being PEEK-rod applied group (30 patients) and rigid rod-applied group (24 patients) The medical histories of all patients were taken, and their neurological examinations were performed, during the second-year preoperative and postoperative controls, and their axial back pain and radicular pain in the second preoperative and postoperative year were questioned. The mean postoperative follow-up period is 29.6 months. Data obtained were evaluated using the VAS Scale And Oswestry Back Pain Disability Questionnaire, and the ODI and VAS scores of all patients were calculated and the changes in the ODI and VAS scores of the two groups were compared. The re-operate histories of the patients were also examined and the data of the two groups were compared. In addition, computed tomography (CT) and magnetic resonance (MR) images of all patients were taken during the preoperative, early postoperative controls and the second-year postoperative controls, and the development of adjacent segment disease and pseudoarthrosis in the second postoperative year were evaluated and the results of the two groups were compared. When evaluating the data obtained in the study, analyses were made using IBM SPSS 23.0 package program (IBM Corp, Armonk, NY). Discussion: The target in spinal surgery is to make pathological conditions, signs and symptoms physiological as much as possible. The purpose of fusion surgery is to correct the abnormal anatomy that led to these signs and symptoms, to eliminate the abnormal movement and to maintain spinal stability. In order for the patient's mobility in daily life to continue as he/she is accustomed to, the load of the segments that become immobilized as a result of fusion surgery falls on other mobile segments, which accelerates the development of degeneration and instability at neighboring levels, as shown in many studies. To avoid such consequences, stabilization systems have become and must become more physiological over time. The clinical results of existing systems will also guide biomechanical studies to be carried out in this context. Our study evaluated the clinical results, re-operate rates with ODI and VAS scores, as well as adjacent segment disease and pseudoarthrosis radiologically. It should be noted that these results are follow-up results of 24-36 months and that different results may be observed in long-term follow-ups. It is therefore extremely important to check patients at regular intervals radiologically and clinically in terms of objective evaluation of the long-term biomechanical utility of the instrument systems used, even if patients have no complaints. Patients adopting a more sedative or active lifestyle in the postoperative period may also trigger or prevent the development of pseudoarthrosis and/or adjacent segment disease. It should also be noted that the ODI and VAS scores of the patients in the postoperative period have a significant effect on the lifestyle of the patients during this period. It was observed that there was a statistically significant decrease in the second-year postoperative ODI and VAS scores of all patients compared to the preoperative values. Although the ODI and VAS scores of the patients in the PEEK rod-applied group decreased more than the ODI and VAS scores of the patients in the rigid rod-applied group, no statistically significant difference was found between the two groups in terms of change in ODI and VAS scores. Reoperation rates were also higher in the rigid rod-applied group compared to the PEEK rod-applied group, but this difference was not statistically significant. The examination of the radiological results revealed that the rates of development of pseudoarthrosis and adjacent segment disease in the rigid rod-applied group were higher than the rates in the PEEK rod-applied group, but there was no statistically significant difference between the two groups. Conclusion: It has been seen that PEEK rods are a good alternative to rigid rods in short segment lumbar transpedicular stabilization surgery performed in patients with lumbar degenerative spine, but they do not have a distinct advantage over rigid rods clinically and radiologically. Although it is not statistically significant, it should not be overlooked that PEEK rods produce more positive clinical and radiological results compared to rigid rods. Moreover, it should be kept in mind that these results are the clinical and radiological results of a study with a short follow-up period, and it should be taken into account that more meaningful clinical and radiological results can be obtained as the number of cases increases and the follow-up period increases. Key Words: PEEK rod, rigid rod, pseudoarthrosis, adjacent segment disease, re-operate