Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?

Kim, Hee Jin; Elysée, Jonathan; Shaffrey, Christopher I.; Burton, Douglas C.; Ames, Christopher P.; Hostin, Richard A.; Bess, Shay; Klineberg, Eric O.; Smith, Justin S.; Passias, Peter G.; Schwab, Frank J.; Lafage, Renaud

doi:10.1177/2192568219879085

Cited by 8 publications

(3 citation statements)

References 23 publications

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“…Insufficient correction of global imbalance in spinal deformity surgery is an indicator of the likelihood of subsequent mechanical complications. 31,32 Kim et al 33 reported an increase in cervical SVA when PJK was present in the upper thoracic region. The compensatory action of cervical curvature after ASD corrective surgery occurs over time in case of fusion of the middle or upper thoracic segments.…”

Section: Discussionmentioning

confidence: 99%

Risk factors for unplanned reoperation after corrective surgery for adult spinal deformity

Ryu

et al. 2023

Bone Joint Res

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AimsTo determine the major risk factors for unplanned reoperations (UROs) following corrective surgery for adult spinal deformity (ASD) and their interactions, using machine learning-based prediction algorithms and game theory.MethodsPatients who underwent surgery for ASD, with a minimum of two-year follow-up, were retrospectively reviewed. In total, 210 patients were included and randomly allocated into training (70% of the sample size) and test (the remaining 30%) sets to develop the machine learning algorithm. Risk factors were included in the analysis, along with clinical characteristics and parameters acquired through diagnostic radiology.ResultsOverall, 152 patients without and 58 with a history of surgical revision following surgery for ASD were observed; the mean age was 68.9 years (SD 8.7) and 66.9 years (SD 6.6), respectively. On implementing a random forest model, the classification of URO events resulted in a balanced accuracy of 86.8%. Among machine learning-extracted risk factors, URO, proximal junction failure (PJF), and postoperative distance from the posterosuperior corner of C7 and the vertical axis from the centroid of C2 (SVA) were significant upon Kaplan-Meier survival analysis.ConclusionThe major risk factors for URO following surgery for ASD, i.e. postoperative SVA and PJF, and their interactions were identified using a machine learning algorithm and game theory. Clinical benefits will depend on patient risk profiles.Cite this article: Bone Joint Res 2023;12(4):245–255.

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Section: Discussionmentioning

confidence: 99%

Risk factors for unplanned reoperation after corrective surgery for adult spinal deformity

Ryu

et al. 2023

Bone Joint Res

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“…Studies have shown that ASD patients with upper instrumented vertebrae (UIV) located at lower thoracic vertebrae (T8-L1) have a higher incidence of PJK than patients with UIV located at upper thoracic vertebrae (T1–T7), indicating that the unfused segments of the thoracic vertebrae had a certain compensatory capacity [ 9 ]. In a sense, the development and progression of PJK may be a compensatory mechanical in the case of residual post-operative global malalignment.…”

Section: Introductionmentioning

confidence: 99%

Proximal junctional kyphosis is a compensation for post-operative negative C2-FH in ASD patients: a cross-sectional study

et al. 2022

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Background Recent studies have found that C2-FH is close to 0 cm in both standing and sitting position for asymptomatic adults. We hypothesize that the thoracic spine may compensate with PJK when the immediate post-operative C2-FH was not ideally restored in adult spinal deformity (ASD). Methods The inclusion criteria were as follows: ASD patients over 45 years old; Cobb angle > 30°; with posterior spinal correction surgery; at least 2 years follow-up. C2-FH was defined as the distance between the femoral heads to the C2 vertical line. All participants were divided into two groups according to the occurrence of PJK at the last follow-up: PJK group and non-PJK group. Results 68 ASD patients, with a minimum follow-up of 2.5 years, were included. PJK was found in 24 patients (35.3%) while the rest 44 patients remained no sagittal malalignment. Immediately post-operative C2-FH showed significant difference between PJK group and non-PJK group (p = 0.015). However, at the last follow-up, C2-FH showed no significant difference between PJK and non-PJK group and the mean value of C2-FH in both groups was approximately − 1 cm, indicating that ASD patients could develop various compensatory mechanisms to maintain sagittal global balance. The AUC was 0.84 (95%CI 0.68–0.97), indicating the well effectiveness of ROC curve and cut-off value in predicting occurrence of PJK in ASD patients. Based on the ROC curve, the optimal cut-off value of C2-FH as indicators for occurrence of PJK was − 42.3 mm. Conclusion Immediate postoperative negative global malalignment (C2-FH < − 42.3 mm) may predict proximal junctional kyphosis in ASD patients. The normal value of C2-FH, − 1 cm, may be the target of global sagittal compensation, and PJK is a compensatory mechanism. Trial registration: 2021-LCYJ-DBZ-05, 2021.07, Retrospective study.

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“…2A-B). 10 Patient risk factors for junctional kyphosis include poor bone quality (osteopenia or osteoporosis, malignancy, infection) and neuromuscular disorders. 11 Radiographic factors that may contribute to junctional kyphosis include a greater degree of preoperative junctional kyphosis as well as a high degree of sagittal malalignment as measured by SVA.…”

Section: Introductionmentioning

confidence: 99%

Failures in Thoracic Spinal Fusions and Their Management

et al. 2021

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Instrumented fixation and fusion of the thoracic spine present distinct challenges and complications including pseudarthrosis and junctional kyphosis. When complications arise, morbidity to the patient can be significant, involving neurologic injury, failure of instrumentation constructs, as well as iatrogenic spinal deformity. Causes of fusion failure are multifactorial, and incompletely understood. Most likely, a diverse set of biomechanical and biologic factors are at the heart of failures. Revision surgery for thoracic fusion failures is complex and often requires revision or extension of instrumentation, and frequently necessitates complex soft tissue manipulation to manage index level injury or to augment the changes of fusion.

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Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter?

Cited by 8 publications

References 23 publications

Risk factors for unplanned reoperation after corrective surgery for adult spinal deformity

Risk factors for unplanned reoperation after corrective surgery for adult spinal deformity

Proximal junctional kyphosis is a compensation for post-operative negative C2-FH in ASD patients: a cross-sectional study

Failures in Thoracic Spinal Fusions and Their Management

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