Proximal Junctional Problems in Surgical Treatment of Lumbar Degenerative Sagittal Imbalance Patients and Relevant Risk Factors

Abstract

Study Design: Retrospective study. Objectives: As we analyze the incidence and the risk factor for proximal junctional problem after surgical treatment of lumbar degenerative sagittal imbalance, we want to contribute to reducing the junctional problem of surgical treatment of lumbar degenerative sagittal imbalance. Summary of Literature Review: Surgical treatment of degenerative spinal deformity has increased. Rigid fixation was a risk factor for degenerative change of adjacent segment and failure, and it remains a big challenge for the junctional problem of surgical treatment. However, research on the correlation with risk factors is rare. Materials and Methods: Forty four patients (mean age 66.5; range, 50-74) who had surgery due to lumbar degenerative sagittal imbalance were evaluated by the risk factor associated with junctional problems from January, 2005 to December, 2011. The risk factors were analyzed by surgical factor (proximal fusion level, using iliac screw, correction or undercorrection of lumbar lordosis compared with pelvic incidence) and patient factor (age, bone marrow density, body mass index). Results: Junctional problems occurred in 18 patients (41%) out of 44 patients. Among these problems, there were 10 cases of fractures, 8 cases of junctional kyphosis, and 4 cases of proximal screw pull out. . Among the risk factors, only the correction or undercorrection of lumbar lordosis compared with pelvic incidence in surgical factor was statistically significant. Other surgical factors and patient factors were not statistically significant. Conclusions: Junctional problems after a surgical treatment of lumbar degenerative sagittal imbalance were common. However, we could not know the exact risk factor of junctional problems except the degree of correction of lumbar lordosis compared with pelvic incidence, because most of the risk factors were not statistically significant. So, further evaluations of the risk factor of lumbar degenerative sagittal imbalance are required.