Effect of overcorrection on proximal junctional kyphosis in adult spinal deformity: analysis by age-adjusted ideal sagittal alignment

• Published in: The spine journal 2022-04, Vol.22 (4), p.635-645
• Main Authors: Byun, Chan Woong, Cho, Jae Hwan, Lee, Choon Sung, Lee, Dong-Ho, Hwang, Chang Ju
• Format: Article
• Language: English
• Subjects: Adult; Adult spinal deformity; Age; Animals; Humans; Kyphosis - complications; Kyphosis - diagnostic imaging; Kyphosis - surgery; Lordosis - diagnostic imaging; Lordosis - etiology; Lordosis - surgery; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - surgery; Postoperative Complications - epidemiology; Postoperative Complications - etiology; Proximal junctional kyphosis; Retrospective Studies; Sagittal alignment; Spinal Fusion - adverse effects; Spinal Fusion - methods; Visual Analog Scale
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2021.10.019

•Overcorrected patients had a significantly higher PJK rate in the age-adjusted analysis (48.3%, 26.5%, and 13.3% for groups O, I, and U, respectively; p=.041).•The degree of postoperative LL correction relative to the PI is a risk factor for the development of PJK (11.4° for PJK vs. 0.2° for non-PJK, p=.033).•Inferior clinical outcomes (back VAS and ODI) were found in patients with PJK.•To reduce the risk of PJK, surgeon's should take age-adjusted parameters into account and exercise caution not to overcorrect patients with low PI. The effect of the degree of lumbar lordosis (LL) correction on proximal junctional kyphosis (PJK) has not been analyzed in context of the age-adjusted sagittal alignment goal. To determine the effect of sagittal correction on the incidence of PJK after an age-adjusted analysis in patients with adult spinal deformity (ASD). Retrospective comparative study. Seventy-eight ASD patients who underwent deformity correction. Visual analog scale (VAS), Oswestry Disability Index (ODI), and imaging. This study included 78 ASD patients who underwent deformity correction and were followed-up more than 2 years. Patients were grouped according to the degree of LL correction relative to pelvic incidence (PI) by adjusting for age using the following formula: (age-adjusted ideal PI - LL) - (postoperative PI - LL). These were group U (undercorrection; 10˚, N=29). Various clinical and radiological parameters were compared among groups. The risk factors for PJK were also evaluated. The overall incidence of PJK was 32.1% (25/78), with significantly higher PJK rate in group O (48.3%) compared with groups U (13.3%) and I (26.5%) (p=.041). The degree of postoperative LL correction relative to the PI by adjusting for age was a risk factor for the development of PJK (11.4° for PJK vs. 0.2° for non-PJK, p=.033). In addition, 2-year postoperative VAS (7.0 vs. 3.4, p