Lafage Renaud, Passias Peter, Sheikh Alshabab Basel, Bess Shay, Smith Justin S, Klineberg Eric, Kim Han Jo, Elysee Jonathan, Shaffrey Christopher, Burton Douglas, Hostin Richard, Mundis Gregory, Schwab Frank, Lafage Virginie
Department of Orthopedics, Hospital for Special Surgery, New York, NY, USA.
Department of Orthopedics, NYU Langone Orthopedic Hospital, New York, NY, USA.
Global Spine J. 2023 Sep;13(7):1737-1744. doi: 10.1177/21925682211047461. Epub 2022 Feb 28.
Retrospective cohort study.
Investigate the patterns of fused lumbar alignment in patients requiring revision surgery for proximal junctional kyphosis (PJK).
Fifty patients (67.8 yo, 76% female) with existing thoraco-lumbar fusion (T10/12 to pelvis) and indicated for surgical correction for PJK were included. To investigate patterns of radiographic alignment prior to PJK revision, unsupervised 2-step cluster analysis was run on parameters describing the fused lumbar spine (PI-LL) to identify natural independent groups within the cohort. Clusters were compared in terms of demographics, pre-operative alignment, surgical parameters, and post-operative alignment. Associations between pre- and post-revision PJK angles were investigated using a Pearson correlation analysis.
Analysis identified 2 distinct patterns: Under-corrected (UC, = 12, 32%) vs over-corrected (OC, = 34, 68%) with a silhouette of .5. The comparison demonstrated similar pelvic incidence (PI) and PJK angle but significantly greater deformity for the UC vs OC group in terms of PI-LL, PI-LL offset, pelvic tilt, and sagittal vertebral axis. The surgical strategy for PJK correction did not differ between the 2 groups in terms of approach, American Society of Anesthesiologists grade, decompression, use of osteotomy, interbody fusion, or fusion length. The post-revision PJK angle significantly correlated with the amount of PJK correction within the OC group but not within the UC group.
This study identified 2 patterns of lumbar malalignment associated with severe PJK: over vs under corrected. Despite the difference in PJK etiology, both patterns underwent the same revision strategy. Future analysis should look at the effect of correcting focal deformity alone vs correcting focal deformity and underlying malalignment simultaneously on recurrent PJK rate.
回顾性队列研究。
调查因近端交界性后凸畸形（PJK）需要翻修手术的患者中融合腰椎排列的模式。
纳入50例患者（平均年龄67.8岁，76%为女性），这些患者已行胸腰段融合术（T10/12至骨盆），且因PJK需手术矫正。为了研究PJK翻修术前的影像学排列模式，对描述融合腰椎（PI-LL）的参数进行无监督两步聚类分析，以确定队列中的自然独立组。对聚类在人口统计学、术前排列、手术参数和术后排列方面进行比较。使用Pearson相关分析研究翻修前后PJK角度之间的关联。
分析确定了2种不同模式：矫正不足（UC，n = 12，32%）与矫正过度（OC，n = 34，68%），轮廓系数为0.5。比较显示两组骨盆发生率（PI）和PJK角度相似，但在PI-LL、PI-LL偏移、骨盆倾斜和矢状椎体轴方面，UC组的畸形明显大于OC组。两组在PJK矫正的手术策略上，在手术入路、美国麻醉医师协会分级、减压、截骨术的使用、椎间融合或融合长度方面没有差异。翻修后PJK角度在OC组中与PJK矫正量显著相关，而在UC组中则不然。
本研究确定了与严重PJK相关的2种腰椎排列不齐模式：矫正过度与矫正不足。尽管PJK病因不同，但两种模式都采用相同的翻修策略。未来的分析应研究单独矫正局部畸形与同时矫正局部畸形和潜在排列不齐对复发性PJK发生率的影响。
