1Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; and.
2Department of Orthopedic Surgery, Haeundae Bumin Hospital, Busan, South Korea.
J Neurosurg Spine. 2023 Sep 1;39(6):765-773. doi: 10.3171/2023.7.SPINE23103. Print 2023 Dec 1.
Proximal junctional fracture (PJFx) at the uppermost instrumented vertebra (UIV) or UIV+1 is the most common mechanism of proximal junctional failure (PJF). Few studies have assessed radiographic progression after PJFx development. Therefore, this study sought to identify the risk factors for radiographic progression of PJFx in the surgical treatment for adult spinal deformity.
In this retrospective study, among 317 patients aged > 60 years who underwent ≥ 5-level fusion from the sacrum, 76 with PJFx development were included. On the basis of the change in the proximal junctional angle (PJA), 2 groups were created: progression group (group P) (change ≥ 10°) and nonprogression group (group NP) (change < 10°). Patient, surgical, and radiographic variables were compared between the groups with univariate and multivariate analyses to demonstrate the risk factors for PJFx progression. The receiver operating characteristic (ROC) curve was used to calculate cutoff values. Clinical outcomes, such as visual analog scale (VAS) scores for back and leg pain, Oswestry Disability Index (ODI) score, the Scoliosis Research Society (SRS)-22 score, and the revision rate were compared between the 2 groups.
The mean age at index surgery was 71.1 years, and 67 women were enrolled in the study (88.2%). There were 45 patients in group P and 31 in group NP. The mean increase in PJA was 15.6° (from 23.2° to 38.8°) in group P and 3.7° (from 17.2° to 20.9°) in group NP. Clinical outcomes were significantly better in group NP than group P, including VAS-back score, ODI score, and SRS-22 scores for all items. The revision rate was significantly greater in group P than in group NP (53.3% vs 25.8%, p = 0.001). Multivariate analysis revealed that overcorrection relative to the age-adjusted ideal pelvic incidence (PI)-lumbar lordosis (LL) target at index surgery (OR 4.484, p = 0.030), PJA at the time of PJFx identification (OR 1.097, p = 0.009), and fracture at UIV (vs UIV+1) (OR 3.410, p = 0.027) were significant risk factors for PJFx progression. The cutoff value of PJA for PJFx progression was calculated as 21° by using the ROC curve.
The risk factors for further progression of PJFx were overcorrection relative to the age-adjusted PI-LL target at index surgery, PJA > 21° at initial presentation, and fracture at the UIV level. Close monitoring is warranted for such patients in order to not miss timely revision surgery.
最上固定椎（UIV）或 UIV+1 处的近端交界区骨折（PJFx）是近端交界区失效（PJF）最常见的机制。很少有研究评估 PJFx 发展后的放射学进展。因此，本研究旨在确定在成人脊柱畸形手术治疗中 PJFx 放射学进展的危险因素。
在这项回顾性研究中，纳入了 317 名年龄大于 60 岁、接受了从骶骨开始至少 5 个节段融合的患者，其中 76 名患者发生了 PJFx。根据近端交界角（PJA）的变化，将两组分为：进展组（组 P）（变化≥10°）和非进展组（组 NP）（变化<10°）。对两组患者进行单因素和多因素分析，比较患者、手术和放射学变量，以确定 PJFx 进展的危险因素。使用受试者工作特征（ROC）曲线计算截断值。比较两组患者的临床结果，如腰背疼痛的视觉模拟量表（VAS）评分、Oswestry 功能障碍指数（ODI）评分、脊柱侧凸研究协会（SRS）-22 评分和翻修率。
指数手术时的平均年龄为 71.1 岁，研究纳入 67 名女性（88.2%）。组 P 中有 45 名患者，组 NP 中有 31 名患者。组 P 中 PJA 的平均增加量为 15.6°（从 23.2°增加到 38.8°），组 NP 中 PJA 的平均增加量为 3.7°（从 17.2°增加到 20.9°）。组 NP 的临床结果明显优于组 P，包括 VAS-背部评分、ODI 评分和 SRS-22 所有项目评分。组 P 的翻修率明显高于组 NP（53.3%比 25.8%，p=0.001）。多因素分析显示，与年龄校正后的理想骨盆入射角（PI）-腰椎前凸（LL）目标相比，指数手术时的过度矫正（OR 4.484，p=0.030）、PJFx 诊断时的 PJA（OR 1.097，p=0.009）和 UIV 骨折（与 UIV+1 相比）（OR 3.410，p=0.027）是 PJFx 进展的显著危险因素。使用 ROC 曲线计算出 PJFx 进展的 PJA 截断值为 21°。
与指数手术时年龄校正的 PI-LL 目标相比，过度矫正、初始表现时 PJA>21°以及 UIV 骨折是 PJFx 进一步进展的危险因素。对于这些患者，需要密切监测，以免错过及时的翻修手术。
