Risk factors for proximal junctional kyphosis in adult spinal deformity patients with concurrent osteoporosis undergoing long-segment spinal fusion surgery
10.3760/cma.j.cn121113-20230917-00178
- VernacularTitle:合并骨质疏松症的脊柱畸形长节段融合术后近端交界性后凸的危险因素
- Author:
Honghao YANG
1
;
Zhangfu LI
;
Hanwen ZHANG
;
Xinuo ZHANG
;
Yong HAI
Author Information
1. 首都医科大学附属北京朝阳医院骨科，北京 100020
- Keywords:
Osteoporosis;
Spinal fusion;
Kyphosis;
Risk factors
- From:
Chinese Journal of Orthopaedics
2024;44(11):740-747
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity patients with concomitant osteoporosis undergoing long-segment spinal fusion surgery.Methods:A retrospective analysis was conducted on 76 adults spinal deformity patients with osteoporosis who underwent long-segment spinal fusion surgery at the Department of Orthopaedics, Beijing Chaoyang Hospital, between June 2013 and December 2019. The cohort included 19 males and 57 females, with a mean age of 66.26±6.10 years (range, 54-78 years). Patients were categorized into two groups based on the occurrence of PJK within a 2-year postoperative follow-up: the PJK group (21 cases) and the non-PJK group (55 cases). Comparative analyses were performed on baseline characteristics, surgical details, preoperative and postoperative spinal-pelvic parameters, Hounsfield Units (HU) of the vertebral bodies, and paraspinal muscle morphology between the groups. Spinal-pelvic parameters included the main Cobb angle, lumbar lordosis (LL), lumbosacral lordosis (LSL), sagittal vertical axis (SVA), T 1 pelvic angle (TPA), pelvic tilt (PT), sacral slope (SS), and pelvic incidence (PI). Preoperative CT was used to measure HU values at the upper instrumented vertebra (UIV), UIV+1, and UIV+2. Paraspinal muscle morphology, including the relative functional cross-sectional area (rFCSA) and functional muscle-fat index (FMFI) at the L 4 lower endplate level, was assessed using preoperative MRI. Optimal cutoff values for HU and paraspinal muscle parameters were determined using receiver operating characteristic curve analysis. Multivariable logistic regression was employed to identify independent risk factors for PJK. Results:Significant differences were observed between the PJK and non-PJK groups in preoperative PT (17.60°±8.39° vs. 24.12°±9.37°), postoperative LL (35.61°±10.62° vs. 42.22°±13.11°), LSL (30.24°±10.10° vs. 35.87°±11.12°), and SVA (37.82°±20.46° vs. 21.37°±17.35°). The differences were statistically significant ( P<0.05). The HU values of UIV (113.62±17.25 vs. 133.94±16.61), UIV+1 (123.14±16.03 vs. 138.27±13.69), and UIV+2 (121.00±15.91 vs. 134.47±15.53) were significantly lower in the PJK group ( P<0.05). Optimal cutoff values for HU at UIV, UIV+1, and UIV+2 were identified as 120.72, 127.51, and 121.50, respectively. Significant differences were also found in rFCSA (156.87±48.06 vs. 204.87±50.16) and FMFI (0.31±0.10 vs. 0.23±0.09). The differences were statistically significant( P<0.05), with optimal cutoff values of 175.43 for rFCSA and 0.24 for FMFI. Multivariable logistic regression analysis indicated that postoperative SVA [ OR=1.049, 95% CI (1.003, 1.097), P=0.037], HU of UIV [ OR=0.938, 95% CI (0.887, 0.991), P=0.024], and rFCSA of paraspinal muscles [ OR=0.883, 95% CI (0.792, 0.983), P=0.023] were independent risk factors for PJK. Conclusion:Reduced HU values of the UIV, decreased rFCSA of lumbar paraspinal muscles, and inadequate sagittal alignment correction are independent risk factors for PJK in adult spinal deformity patients with osteoporosis undergoing long-segment spinal fusion surgery.
