Analysis of sagittal spinopelvic parameters in proximal junctional kyphosis after long-segment fixation to the pelvis for lumbar degenerative diseases

Background Proximal junctional kyphosis (PJK) is a common long-term complication of lumbar degenerative scoliosis, but few studies have examined PJK after long-segment posterior spinal fixation extending to the pelvis for lumbar degenerative diseases. Therefore, this study aimed to identify potential causative factors by analyzing and comparing the sagittal spinopelvic parameters between patients with and without PJK after long-segment internal fixation extending to the pelvis for lumbar degenerative diseases. Methods This retrospective study enrolled patients who underwent posterior long-segment internal fixation extending to the pelvis with selective decompression and bone graft fusion for lumbar degenerative diseases at the First Medical Center of PLA General Hospital, China, from January 2015 to January 2019. The changes and differences in sagittal spinal-pelvis-joint parameters were compared between and within groups. Results In total, 108 patients were included in this study. The long-segment internal fixation group comprised 55 patients (males: n = 31; mean age: 63.1 ± 8.5 years). When seated, the changes of Sagittal Vertical Axis (SVA), Lumbar Lordosis (LL), T1 Pelvic Angle (TPA), T1 Spinopelvic Inclination (T1SPI), and PJA were significantly different (P <0.05). Conclusions The changes in sagittal parameters underscore the need to consider the overall sagittal alignment of the spine and its relationship with the pelvis and hip to improve the patients’ quality of life and reduce the incidence of long-term complications after spinal surgery. Clinical trial number: not applicable